WO2020055635A1

WO2020055635A1 - Glass manufacturing apparatus and methods for using the same

Info

Publication number: WO2020055635A1
Application number: PCT/US2019/049446
Authority: WO
Inventors: Xinghua Li; Anping Liu; Michael Yoshiya Nishimoto; William Anthony Whedon
Original assignee: Corning Incorporated
Priority date: 2018-09-14
Filing date: 2019-09-04
Publication date: 2020-03-19
Also published as: TW202021708A

Abstract

A glass manufacturing apparatus and a method of using the same can include a laser and an optical fiber. The optical fiber can include a first end and a second end. The laser is optically coupled to the first end of the fiber. The second end of the optical fiber can face a molten material travel path. Using the apparatus, a laser beam can be transmitted from the laser into the first end of the optical fiber. The laser beam can be propagated along the optical fiber to the first end of the optical fiber to the second end of the optical fiber. The laser beam can be transmitted from the second end of the fiber to impinge a target location of a molten material flowing along the molten material travel path to heat a portion of the molten material at the target location.

Description

GLASS MANUFACTURING APPARTUS AND METHODS FOR USING THE

SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 62/731,180 filed on September 14, 2018 the contents of which are relied upon and incorporated herein by reference in their entirety as if fully set forth below.

FIELD

[0001] The present disclosure relates generally to a glass manufacturing apparatus and methods for using the same and, more particularly, to a glass manufacturing apparatus comprising a laser and methods for using the same.

BACKGROUND

[0002] Glass sheets can be used in photovoltaic applications or display applications, for example liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), and plasma display panels (PDPs). Glass sheets are commonly fabricated by a flowing molten glass to a forming body whereby a glass web may be formed by a variety of web forming processes, for example, slot draw, float, down-draw, fusion down-draw, rolling, tube drawing, or up- draw. The glass web may be periodically separated into individual glass sheets. For a variety of applications, controlling a thickness of a glass sheet is desirable.

SUMMARY

[0003] The following presents a simplified summary of the disclosure to provide a basic understanding of some embodiments described in the detailed description.

[0004] In accordance with some embodiments, a glass manufacturing apparatus can comprise an optical fiber and a laser. The optical fiber can comprise a first end and a second end. The laser can be optically coupled to the first end of the optical fiber. The second end of the optical fiber can face a molten material travel path. [0005] In some embodiments, the glass manufacturing apparatus can further comprise a housing comprising a wall defining an interior area. The optical fiber can at least partially extend through a passage in the wall of the housing.

[0006] In further embodiments, the passage through the wall of the housing of the glass manufacturing apparatus can comprise a cross-sectional passage area perpendicular to an elongated axis of the optical fiber. The cross-sectional passage area is in a range from about 0.01 millimeters² to about 500 millimeter².

[0007] In further embodiments, the passage through the wall of the housing of the glass manufacturing apparatus can comprise a cross-sectional passage area perpendicular to an elongated axis of the optical fiber. The cross-sectional passage area is in a range from about 0.01 micrometers² to about 5 millimeter².

[0008] ln some embodiments, the glass manufacturing apparatus can comprise a tube. The optical fiber can at least partially extend through the tube.

[0009] In further embodiments, the tube of the glass manufacturing apparatus can comprise a ceramic material.

[0010] In other embodiments, the glass manufacturing apparatus can further comprise a forming vessel. The second end of the optical fiber can face a target location below the forming vessel.

[0011] In still other embodiments, the glass manufacturing apparatus can further comprise a forming vessel. The second end of the optical fiber can face a target location on a surface of the forming vessel.

[0012] In some embodiments, the laser of the glass manufacturing apparatus can be configured to emit a laser beam comprising a wavelength in a range from about 760 nanometers (nm) to about 5,000 nanometers.

[0013] In some embodiments, the laser of the glass manufacturing apparatus can be configured to emit a laser beam comprising a wavelength in a range from about 760 nanometers (nm) to about 1,700 nanometers.

[0014] In some embodiments, the laser of the glass manufacturing apparatus can comprise a laser diode.

[0015] In further embodiments, the laser diode of the glass manufacturing apparatus can comprise an AlGaAs laser diode, an InGaAsP laser diode, or an InGaAsN laser diode.

[0016] In some embodiments, the optical fiber of the glass manufacturing apparatus can comprise a plurality of optical fibers further comprising corresponding second ends. The second ends of the plurality of optical fiber can face the molten material travel path and be arranged as an array in a direction transverse to the molten material travel path.

[0017] In other embodiments, the optical fiber of the glass manufacturing apparatus can comprise sapphire, fused silica, or quartz.

[0018] In accordance with other embodiments, a method of manufacturing glass using the glass manufacturing apparatus can comprise flowing molten material along the molten material travel path. The method can also comprise transmitting a laser beam from the laser into the first end of the optical fiber. The method can further comprise propagating the laser beam along the optical fiber from the first end of the optical fiber to the second end of the optical fiber. The method can additionally comprise transmitting the laser beam from the second end of the optical fiber. Also, the method can comprise impinging a target location of the molten material with the laser beam. The portion of the molten material at the target location is heated.

[0019] In some embodiments, the method of manufacturing glass can further comprise determining a deviation of a thickness of the portion of the molten material from a predefined thickness. Heating the target location with the laser beam can decrease a viscosity of the portion of the molten material to reduce the deviation of the thickness of the portion of the molten material from the predefined thickness.

[0020] In further embodiments, the target location of the molten material can be position below the forming vessel in the method of manufacturing glass. The laser beam can heat the portion of molten material comprising a glass ribbon extending below the forming vessel.

[0021] In other embodiments, method of manufacturing glass can further comprise impinging a laser beam on a surface of a forming vessel. The laser beam can heat a portion of the surface of the forming vessel.

[0022] In some embodiments, a wavelength of the laser beam in the method of glass manufacturing can be in a range from about 760 nanometers (nm) to about 5,000 nanometers.

[0023] In some embodiments, a wavelength of the laser beam in the method of glass manufacturing can be in a range from about 760 nanometers (nm) to about 1,700 nanometers.

[0024] In other embodiments, the laser beam impinging on the target location of the molten material in the method of manufacturing glass can comprise a power density in a range from about 1 watt/centimeter² (W/cm²) to about 2,000 watts/centimeter².

[0025] In other embodiments, the laser beam impinging on the target location of the molten material in the method of manufacturing glass can comprise a power density in a range from about 1 watt/centimeter² (W/cm²) to about 200 watts/centimeter².

[0026] In still some embodiments, the laser in the method of manufacturing glass can comprise a laser diode.

[0027] In further embodiments, the laser diode in the method of manufacturing glass can comprise an AlGaAs laser diode, an InGaAsP laser diode, or an InGaAsN laser diode.

[0028] In other embodiments, the laser beam impinging the target location of the molten material can comprise an absorption depth of the molten material of about 50 micrometers (pm) or more in the method of manufacturing glass.

[0029] In some other embodiments, the laser beam can impinge the target location of the molten material at an about normal angle of incidence in the method of manufacturing glass.

[0030] In other embodiments, a maximum width across the molten material travel path of the target location of the molten material impinged by the laser beam can be in a range from about 100 micrometers (pm) to about 30 millimeters (mm) in the method of manufacturing glass.

[0031] In still other embodiments, the second end of the optical fiber can be moved relative to the molten material travel path.

[0032] In yet other embodiments, the optical fiber can comprise a plurality of optical fibers comprising corresponding second ends in a method of manufacturing glass. The corresponding second ends of the plurality of optical fibers can face the molten material travel path and be arranged as an array in a direction transverse to the molten material travel path. Also, impinging the target location of the molten material comprises impinging the molten material at a plurality of locations with respective laser beams.

[0033] Additional features and advantages of the embodiments disclosed herein will be set forth in the detailed description that follows, and in part will be clear to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and character of the embodiments disclosed herein. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure, and together with the description explain the principles and operations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] These and other features, aspects and advantages are better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0035] FIG. 1 schematically illustrates an exemplary embodiment of a glass manufacturing apparatus in accordance with some embodiments of the disclosure;

[0036] FIG. 2 shows a cross-sectional view of a glass manufacturing apparatus taken along lines 2— 2 of FIG. 1 in accordance with some embodiments of the disclosure;

[0037] FIG. 3 is an enlarged view 3 of FIG. 2;

[0038] FIG. 4 illustrates another cross-sectional view of a glass manufacturing apparatus taken along lines 2— 2 of FIG. 1 in accordance with some embodiments of the disclosure;

[0039] FIG. 5 is an enlarged view 5 of FIG. 4;

[0040] FIG. 6 illustrates a right cross-sectional view of a glass manufacturing apparatus taken along lines 6— 6 of FIG. 2;

[0041] FIG. 7 illustrates an alternative right cross-sectional view of a glass manufacturing apparatus taken along lines 6— 6 of FIG. 2;

[0042] FIG. 8 illustrate a cross-sectional view of a glass manufacturing apparatus taken along lines 8— 8 of FIG. 6 in accordance with the embodiments of the disclosure;

[0043] FIG. 9 illustrates a side view of a glass manufacturing apparatus taken along lines 9— 9 of FIG. 7 in accordance with the embodiments of the disclosure; and [0044] FIG. 10 illustrates a temperature profile as a function of distance for different combinations of materials using an exemplary embodiment, in accordance with the embodiments of the disclosure.

DETAILED DESCRIPTION

[0045] Embodiments will now be described more fully hereinafter with reference to the accompanying drawings in which exemplary embodiments are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0046] In some embodiments, methods of separating a glass web may be used in conjunction with a glass manufacturing apparatus configured to fabricate a glass ribbon although other glass processing apparatus may be provided in further embodiments. In some embodiments, the glass manufacturing apparatus can comprise a slot-draw apparatus, float-bath apparatus, down-draw apparatus (e.g. fusion draw apparatus), up-draw apparatus, press-rolling apparatus, or other glass ribbon manufacturing apparatus. The glass ribbon from any of these processes may then be subsequently divided to provide glass sheets suitable for further processing into a desired application (e.g., a display application). For example, the glass sheets can be used in a wide range of display applications, including liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), or the like. Glass sheets may need to be transported from one location to another. The glass sheets may be transported with a conventional support frame designed to secure a stack of glass sheets in place. Moreover, interleaf material can be placed between each sheet of glass to help prevent contact and therefore preserve the pristine surfaces of the glass sheets.

[0047] As schematically illustrated in FIG. 1, in some embodiments, a glass manufacturing apparatus 100 can include a glass forming apparatus 101 including a forming vessel 140 designed to produce a glass ribbon 103 from a quantity of molten material 121. As used herein, the term“glass ribbon” refers to material after it is drawn from the forming vessel 140 even when the material is not in a glassy state (i.e., above its glass transition temperature). In some embodiments, the glass ribbon 103 can include a central portion 152 disposed between opposite, relatively thick edge beads formed along a first outer edge 153 and a second outer edge 155 of the glass ribbon 103. Additionally, in some embodiments, a glass sheet 104 can be separated from the glass ribbon 103 along a separation path 151 by a glass separator 149 (e.g., scribe, score wheel, diamond tip, laser). In some embodiments, before or after separation of the glass sheet 104 from the glass ribbon 103, the relatively thick edge beads formed along the first outer edge 153 and the second outer edge 155 can be removed to provide the central portion 152 as a glass sheet 104 having a more uniform thickness.

[0048] In some embodiments, the glass manufacturing apparatus 100 can include a melting vessel 105 oriented to receive batch material 107 from a storage bin 109. The batch material 107 can be introduced by a batch delivery device 111 powered by a motor 113. In some embodiments, a controller 115 can optionally be operated to activate the motor 113 to introduce a desired amount of batch material 107 into the melting vessel 105, as indicated by arrow 117. The melting vessel 105 can heat the batch material 107 to provide molten material 121. In some embodiments, a glass melt probe 119 can be employed to measure a level of molten material 121 within a standpipe 123 and communicate the measured information to the controller 115 by way of a communication line 125.

[0049] Additionally, in some embodiments, the glass manufacturing apparatus 100 can include a first conditioning station including a fining vessel 127 located downstream from the melting vessel 105 and coupled to the melting vessel 105 by way of a first connecting conduit 129. In some embodiments, molten material 121 can be gravity fed from the melting vessel 105 to the fining vessel 127 by way of the first connecting conduit 129. For example, in some embodiments, gravity can drive the molten material 121 through an interior pathway of the first connecting conduit 129 from the melting vessel 105 to the fining vessel 127. Additionally, in some embodiments, bubbles can be removed from the molten material 121 within the fining vessel 127 by various techniques.

[0050] In some embodiments, the glass manufacturing apparatus 100 can further include a second conditioning station including a mixing chamber 131 that can be located downstream from the fining vessel 127. The mixing chamber 131 can be employed to provide a homogenous composition of molten material 121, thereby reducing or eliminating inhomogeneity that may otherwise exist within the molten material 121 exiting the fining vessel 127. As shown, the fining vessel 127 can be coupled to the mixing chamber 131 by way of a second connecting conduit 135. In some embodiments, molten material 121 can be gravity fed from the fining vessel 127 to the mixing chamber 131 by way of the second connecting conduit 135. For example, in some embodiments, gravity can drive the molten material 121 through an interior pathway of the second connecting conduit 135 from the fining vessel 127 to the mixing chamber 131.

[0051] Additionally, in some embodiments, the glass manufacturing apparatus 100 can include a third conditioning station including a delivery vessel 133 that can be located downstream from the mixing chamber 131. In some embodiments, the delivery vessel 133 can condition the molten material 121 to be fed into an inlet conduit 141. For example, the delivery vessel 133 can function as an accumulator and/or flow controller to adjust and provide a consistent flow of molten material 121 to the inlet conduit 141. As shown, the mixing chamber 131 can be coupled to the delivery vessel 133 by way of a third connecting conduit 137. In some embodiments, molten material 121 can be gravity fed from the mixing chamber 131 to the delivery vessel 133 by way of the third connecting conduit 137. For example, in some embodiments, gravity can drive the molten material 121 through an interior pathway of the third connecting conduit 137 from the mixing chamber 131 to the delivery vessel 133. As further illustrated, in some embodiments, a delivery pipe 139 can be positioned to deliver molten material 121 to the inlet conduit 141 of the forming vessel 140.

[0052] Various embodiments of forming vessels can be provided in accordance with features of the disclosure including a forming vessel with a wedge for fusion drawing the glass ribbon, a forming vessel with a slot to slot draw the glass ribbon, or a forming vessel provided with press rolls to press roll the glass ribbon from the forming vessel. By way of illustration, the forming vessel 140 shown and disclosed below can be provided to fusion draw the molten material 121 off a root 145 of a forming wedge 209 to produce the glass ribbon 103. For example, in some embodiments, the molten material 121 can be delivered from the inlet conduit 141 to the forming vessel 140. The molten material 121 can then be formed into the glass ribbon 103 based at least in part on the structure of the forming vessel 140. For example, as shown, the molten material 121 can be drawn off the bottom edge (e.g., root 145) of the forming vessel 140 along a draw path extending in a draw direction 154 of the glass manufacturing apparatus 100. In some embodiments, edge directors can direct the molten material 121 off the forming vessel 140 and define, at least in part, a width“W” of the glass ribbon 103. In some embodiments, the width“W” of the glass ribbon 103 can extend between the first outer edge 153 of the glass ribbon 103 and the second outer edge 155 of the glass ribbon 103.

[0053] In some embodiments, the width“W” of the glass ribbon 103 can be about 20 millimeters (mm) or more, about 50 mm or more, about 100 mm or more, about 500 mm or more, about 1,000 mm or more, about 2,000 mm or more, about 3,000 mm or more, about 4000 mm or more, although other widths can be provided in further embodiments. In some embodiments, the width“W” of the glass ribbon 103 can be in a range from about 20 mm to about 4,000 mm, from about 50 mm to about 4,000 mm, from about 100 mm to about 4,000 mm, from about 500 mm to about 4,000 mm, from about 1,000 mm to about 4,000 mm, from about 2,000 mm to about 4,000 mm, from about 3,000 mm to about 4,000 mm, from about 20 mm to about 3,000 mm, from about 50 mm to about 3,000 mm, from about 100 mm to about 3,000 mm, from about 500 mm to about 3,000 mm, from about 1,000 mm to about 3,000 mm, from about 2,000 mm to about 3,000 mm, from about 2,000 mm to about 2,500 mm, and all ranges and subranges therebetween.

[0054] FIGS. 2 and 4 show cross-sectional perspective views of the glass manufacturing apparatus 100 along lines 2— 2 of FIG. 1, according to various embodiments of the disclosure. In some embodiments, the forming vessel 140 can include a trough 201 oriented to receive the molten material 121 from the inlet conduit 141. The forming vessel 140 can further include the forming wedge 209 including a pair of downwardly inclined converging surface portions 207a, 207b extending between opposed ends 210a, 210b (see FIG. 1) of the forming wedge 209. The pair of downwardly inclined converging surface portions 207a, 207b of the forming wedge 209 can converge along the draw direction 154 to intersect along a bottom edge of the forming wedge 209 to define the root 145 of the forming vessel 140. A draw plane 213 of the glass manufacturing apparatus 100 can extend through the root 145 along the draw direction 154. In some embodiments, the glass ribbon 103 can be drawn in the draw direction 154 along the draw plane 213. As shown, the draw plane 213 can bisect the forming wedge 209 through the root 145 although, in some embodiments, the draw plane 213 can extend at other orientations relative to the root 145. [0055] Throughout the disclosure, the molten material travel path 229 is defined as the path that the molten material 121 follows from when it enters the forming vessel 140 until it has cooled to its strain point (i.e., the temperature at which the viscosity of the molten material 121 comprising the glass ribbon 103 exceeds 10^{14 5} Poise). The molten material 121 may cool to its strain point as a glass ribbon 103 before it reaches the separation path 151, although the molten material 121 may cool to its strain point after it crosses the separation path 151 as a glass sheet 104 in further embodiments. For instance, as shown in FIGS. 2-5, the molten material travel path 229 can be defined as the path the molten material 121 travels as it flows over the inclined converging surface portions 207a, 207b and/or the path that the glass ribbon 103 travels after it is drawn off the root 145 of the forming wedge 209.

[0056] Additionally, in some embodiments, the molten material 121 flows into the trough 201 of the forming vessel 140 and then overflows from the trough 201 by simultaneously flowing over corresponding weirs 203a, 203b and downward over the outer surfaces 205a, 205b of the corresponding weirs 203a, 203b. Respective streams of molten material 121 flow along corresponding downwardly inclined converging surface portions 207a, 207b of the forming wedge 209 to be drawn off the root 145 of the forming vessel 140, where the flows converge and fuse into the glass ribbon 103. The glass ribbon 103 can then be drawn off the root 145 in the draw plane 213 along the draw direction 154. In some embodiments, the glass separator 149 (see FIG. 1) can then separate the glass sheet 104 from the glass ribbon 103 along the separation path 151. As illustrated, in some embodiments, the separation path 151 can extend along the width“W” of the glass ribbon 103 between the first outer edge 153 and the second outer edge 155. Additionally, in some embodiments, the separation path 151 can extend perpendicular to the draw direction 154 of the glass ribbon 103. Moreover, in some embodiments, the draw direction 154 can define a direction along which the glass ribbon 103 can be fusion drawn from the forming vessel 140. In some embodiments, the glass ribbon 103 can include a speed as it traverses along draw direction 154 of about 1 millimeters per second (mm/s) or more, about 10 mm/s or more, about 50 mm/s or more, about 100 mm/s or more, or about 500 mm/s or more, for example, in a range from about 1 mm/s to about 500 mm/s, from about 10 mm/s to about 500 mm/s, from about 50 mm/s to about 500 mm/s, from about 100 mm/s to about 500 mm/s, and all ranges and subranges therebetween. [0057] As shown in FIGS. 2 and 4, in some embodiments, the glass ribbon 103 is drawn from the root 145 with a first major surface 215a of the glass ribbon 103 and a second major surface 215b of the glass ribbon 103 facing opposite directions and defining an average thickness“T” of the glass ribbon 103. In some embodiments, the average thickness“T” of the central portion 152 of the glass ribbon 103 can be about 2 mm or less, about 1 mm or less, about 500 micrometers ((mi), about 300 pm or less, about 200 pm or less, about 100 pm or less, although other thicknesses may be provided in further embodiments. For example, in some embodiments, the average thickness“T” of the glass ribbon 103 can be in a range from about 50 pm to about 750 pm, from about 100 pm to about 700 pm, from about 200 pm to about 600 pm, from about 300 pm to about 500 pm, from about 50 pm to about 500 pm, from about 50 pm to about 700 pm, from about 50 pm to about 600 pm, from about 50 pm to about 500 pm, from about 50 pm to about 400 pm, from about 50 pm to about 300 pm, from about 50 pm to about 200 pm, or from about 50 pm to about 100 pm, including all ranges and subranges of thicknesses therebetween. In addition, the glass ribbon 103 can include a variety of compositions including, but not limited to, soda- lime glass, aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, alkali- containing glass, or alkali -free glass, any of which may be free of lithia or not.

[0058] In some embodiments, as shown in FIGS. 2-5, the glass manufacturing apparatus 100 can comprise a housing 218 with a housing wall 220 defined between an inner surface 222 and an outer surface 223 of the housing wall 220. In some embodiments, an interior 221 of the housing 218 can be at least partially defined by the inner surface 222 of the housing wall 220. In some embodiments, the housing wall 220 at least partially surrounds the forming vessel 140 so that the forming vessel 140 and a portion of the glass ribbon 103 are positioned within the interior 221 of the housing 218. As shown, a bulk material of the housing 218, located between the inner surface 222 and the outer surface 223, comprises a first material, which may be a ceramic or other material with a low thermal conductivity. Without wishing to be bound by theory, materials comprising lower thermal conductivities tend to comprise better insulating properties than materials with higher thermal conductivities ln some embodiments, the first material comprises a thermal conductivity of about 150 W m ¹ K ¹ or less, 50 W nr¹ K ¹ or less, of about 30 W nr¹ K ¹ or less, in a range from about 0.01 W nr¹ K ¹ to about 150 W nr¹ K ¹, in a range from about 0.01 W nr¹ K ¹ to about 50 W m ¹ K ¹, or in a range from about 0.25 W m ¹ K ¹ to about 30 W m ¹ K ¹, although other thermal conductivities may be permissible in other embodiments.

[0059] Also, the first material maintains its mechanical properties and dimensional stability at an operating temperature of the interior 221 of the housing 218 when there is molten material 121 in the forming vessel 140. ln some embodiments, the operating temperature may be about 500°C or more, about 800°C or more, about l000°C or more, about 1200° or more, about l500°C or more, about l700°C or less, or about l600°C or less. In some embodiments, the operating temperature may be in a range from about 500°C to about l700°C, from about 800°C to about l700°C, from about l000°C to about l700°C, from about 1200° to about l700°C, from about 500°C to about l600°C, from about 800°C to about l600°C, from about l000°C to about l600°C, or from about 1200° to about l600°C. ln some embodiments, the first material comprises a melting temperature above l600°C. If the first material comprises an amorphous material, the operating temperature may be below the glass transition temperature of that material. In some embodiments, the first material comprises boron nitride (BN), silicon carbide (SiC), zirconium dioxide (ZrC ), a SiAlON (i.e., a combination of alumina and silicon nitride and can have a chemical formula such as Sii2-m-nAl_m+nO_nNi6-n, Sie-nAlnOnNs-n, or Si2-nAl_nOi+_nN2-n, where m, n, and the resulting subscripts are all non-negative integers), aluminum nitride (A1N), graphite, alumina (AI2O3), silicon nitride (S13N4), fused quartz, mullite (i.e., a mineral comprising a combination of aluminum oxide and silicon dioxide), or a combination of two or more of the aforementioned materials.

[0060] The glass manufacturing apparatus 100 comprises one or more heating apparatus 226a, 226b. For example, as shown in FIGS. 2 and 4, the glass manufacturing apparatus 100 may comprise a first heating apparatus 226a and a second heating apparatus 226b with the draw plane 213 positioned between the first heating apparatus 226a and the second heating apparatus 226b. Although two heating apparatus 226a, 226b are shown, a single heating apparatus or more than two heating apparatus may be provided in further embodiments. FIG. 3 is an enlarged view taken at view 3 of FIG. 2 and FIG. 5 is an enlarged view taken at view 5 of FIG. 4. Both FIGS. 3 and 5 discuss features of the first heating apparatus 226a, which will be described more fully with the understanding that such description can also apply to one or more other heating apparatus such as the second heating apparatus 226b. In some embodiments, as shown in FIGS. 2-5, a passage 307 extends through the housing 218 from the outer surface 223 of the housing wall 220 to the inner surface 222 of the housing wall 220. In some embodiments, as shown in FIGS. 2-5, a tube 309 comprising a second material may be positioned within the passage 307 although the passage 307 may be provided without a tube 309 and/or comprise a second material in other embodiments (e.g., see FIGS. 6 and 8).

[0061] In some embodiments, the tube 309 comprises the second material that may be the same as the first material of the housing wall 220. In some embodiments, the second material may comprise a thermal conductivity that is about the same or greater than a thermal conductivity of the first material. In further embodiments, the second material may still comprise a melting temperature of about l600°C or more. For example, the first material may comprise a thermal conductivity less than about 25 W nr¹ K ¹ (e.g., fused quartz, fused silica, zirconium dioxide, mullite, a SiAlON, graphite) and the second material may comprise a thermal conductivity of about 30 W m ¹ K ¹ or more (e.g., silicon nitride, boron nitride, alumina, silicon carbide, aluminum nitride). In some embodiments, the second material may serve to homogenize temperatures within the passage 307 relative to a passage without the second material (e.g., without a tube 309).

[0062] In some embodiments, as shown in FIGS. 7 and 9, the tube 309, if provided, can comprise a plurality of tubes 309a-i that can be positioned with a corresponding one of a plurality of passages 307a-i (i.e., surrounded by the first material of the housing 218). In some embodiments, one or more of the tubes may be fixedly mounted within the corresponding passage. Fixed mounting may be achieved, for example, by press fitting the tube within the passage. In some embodiments, the tube 309 may comprise a lining of the passage 307 that can coat the passage 307.

[0063] ln further embodiments, as shown, one or more of the tubes may be adjustably mounted within the corresponding passage. For instance, a mounting device (e.g., threaded connection) may be adjusted to provide a desired axial adjustment of the tube within the corresponding passage. As shown in FIG. 7, for example, the tubes 309a-f and 309h-i may have outer ends that are adjusted to be flush with a recessed surface 701 of a recess 703 countersunk from the inner surface 222 of the housing wall 220. Alternatively, as shown by tube 309g, the tube may be axially adjusted within the passage 307g such that the end of the tube 309g is not flush with the recessed surface 701. For instance, as shown, the end of the tube 309g can be recessed within the passage 307g although the end of the tube may be adjusted to extend from the passage into the recess 703 and/or the interior 221 of the housing 218 in further embodiments. The ability to axially adjust the tubes relative to the passages, may permit adjustment of the optical fiber relative to the housing while maintaining thermal shielding of the optical fiber. Furthermore, adjustable mounting can facilitate insertion of the tube when installing the tube and/or optical fiber. Still further, adjustable mounting can facilitate removal of a tube and corresponding optical fiber for replacement with another tube and corresponding optical fiber.

[0064] In some embodiments, the tube 309 can comprise a thickness 310 (see FIG. 3) measured between an outer dimension of the tube 309 and an inner dimension of the tube 309. In some embodiments, the thickness 310 of the tube 309 that can be about 100 nm or more, about 1 pm or more, about 10 pm or more, about 50 pm or more, about 2,000 pm or less, about 990 pm or less, about 490 pm or less, about 400 pm or less, about 300 pm or less, about 200 pm or less, or about 100 pm or less. In some embodiments, the thickness 310 of the tube 309 can be in a range from about 100 nm to about 2,000 pm, from about 1 pm to about 2,000 pm, from about 10 pm to about 2,000 pm, from about 50 pm to about 2,000 pm, from about 100 nm to about 990 pm, from about 1 pm to about 990 pm, from about 10 pm to about 990 pm, from about 50 pm to about 990 pm, from about 100 nm to about 490 pm, from about 1 pm to about 490 pm, from about 10 pm to about 490 pm, from about 50 pm to about 490 pm, from about 100 nm to about 400 pm, from about 1 pm to about 400 pm, from about 10 pm to about 400 pm, from about 50 pm to about 400 pm, from about 100 nm to about 300 pm, from about 1 pm to about 300 pm, from about 10 pm to about 300 pm, from about 50 pm to about 300 pm, from about 100 nm to about 200 pm, from about 1 pm to about 200 pm, from about 10 pm to about 200 pm, from about 50 pm to about 200 pm, from about 100 nm to about 100 pm, from about 1 pm to about 100 pm, from about 10 pm to about 100 pm, or from about 50 pm to about 100 pm.

[0065] In other embodiments, as shown in in FIGS. 6 and 8, the second material may comprise a portion of the housing 218 surrounding the passage 307 without a tube 309. In some embodiments, the passage 307 may be in the portion of the housing wall 220 comprising the second material. In some embodiments, as shown in FIGS. 6 and 8, the passage 307 may not be provided with a tube 309. In some embodiments, although not shown, the above -referenced tube 309 comprising a second material (from FIGS. 7 and 9) can optionally be positioned within the passage 307 also comprising a second material (from FIGS. 6 and 8) so that tube 309 can be adjusted or interchanged independent from the housing 218 itself.

[0066] The passage 307 may comprise a cross-section (e.g., in the plane of FIGS. 8 and 9 and perpendicular to an elongated axis of the passage 307) with a cross-sectional passage area. In some embodiments the cross-sectional passage area can be about 0.01 mm² or more, about 0.02 mm² or more, about 0.04 mm² or more, about 0.06 mm² or more, about 0.1 mm² or more, about 500 mm² or less, about 100 mm² or less, about 50 mm² or less, about 10 mm² or less, about 5 mm² or less, about 1 mm² or less, about 0.8 mm² or less, about 0.4 mm² or less, about 0.2 mm² or less, or about 0.1 mm² or less. In some embodiments, the cross-sectional passage area can be in a range from about 0.01 mm² to about 500 mm², from about 0.02 mm² to about 500 mm², from about 0.04 mm² to about 500 mm², from about 0.06 mm² to about 500 mm², from 0.1 mm² to about 500 mm², from about 0.01 mm² to about 100 mm², from about 0.02 mm² to about 100 mm², from about 0.04 mm² to about 100 mm², from about 0.06 mm² to about 100 mm², from 0.1 mm² to about 100 mm², from about 0.01 mm² to about 50 mm², from about 0.02 mm² to about 50 mm², from about 0.04 mm² to about 50 mm², from about 0.06 mm² to about 50 mm², from 0.1 mm² to about 50 mm², from about 0.01 mm² to about 10 mm², from about 0.02 mm² to about 10 mm², from about 0.04 mm² to about 10 mm², from about 0.06 mm² to about 10 mm², from 0.1 mm² to about 10 mm², from about 0.01 mm² to about 5 mm², from about 0.02 mm² to about 5 mm², from about 0.04 mm² to about 5 mm², from about 0.06 mm² to about 5 mm², from 0.1 mm² to about 5 mm², from about 0.01 mm² to about 1 mm², from about 0.02 mm² to about 1 mm², from about 0.04 mm² to about 1 mm², from about 0.06 mm² to about 1 mm², from about 0.1 mm² to about 1 mm², from about 0.01 mm² to about 0.8 mm², from about 0.02 mm² to about 0.8 mm², from about 0.04 mm² to about 0.8 mm², from about 0.06 mm² to about 0.8 mm², from about 0.1 mm² to about 0.8 mm², from about 0.01 mm² to about 0.4 mm², from about 0.02 mm² to about 0.4 mm², from about 0.04 mm² to about 0.4 mm², from about 0.06 mm² to about 0.4 mm², from about 0.1 mm² to about 0.4 mm², from about 0.01 mm² to about 0.2 mm², from about 0.02 mm² to about 0.2 mm², from about 0.04 mm² to about 0.2 mm², from about 0.06 mm² to about 0.2 mm², from about 0.1 mm² to about 0.2 mm², from about 0.01 mm² to about 0.1 mm², from about 0.02 mm² to about 0.1 mm², from about 0.02 mm² to about 0.1 mm², from about 0.04 mm² to about 0.1 mm², or from about 0.1 mm² to about 0.6 mm². In some embodiments, the cross-sectional passage area can be minimized to reduce the amount of heat transferred through the passage 307 while still accommodating an optical fiber 305 (discussed below) that may extend into the passage 307, a tube 309 if present, and a laser beam 301 (discussed below).

[0067] As shown in FIG. 2, the heating apparatus 226a, 226b may also comprise a laser 601 that can comprise a gas laser, an excimer laser, a dye laser, or a solid-state laser. Example embodiments of gas lasers include helium, neon, argon, krypton, xenon, helium-neon (HeNe), xenon-neon (XeNe), carbon dioxide (C0₂), coper (Cu) vapor, gold (Au) vapor, cadmium (Cd) vapor, ammonia, hydrogen fluoride (HF), and deuterium fluoride (DF). Example embodiments of excimer lasers include chlorine, fluorine, iodine, or dinitrogen oxide (N2O) in an inert environment comprising argon (Ar), krypton (Kr), xenon (Xe), or a combination thereof. Example embodiments of dye lasers include those using organic dyes such as rhodamine, fluorescein, coumarin, stilbene, umbelliferone, tetracene, or malachite green dissolved in a liquid solvent. Example embodiments of solid-state lasers include crystal lasers, fiber lasers, and laser diodes. Crystal-based lasers comprise a host crystal doped with a lanthanide, or a transition metal. Example embodiments of host crystals include yttrium aluminum garnet (YAG), yttrium lithium fluoride (YLF), yttrium othoaluminate (YAL), yttrium scandium gallium garnet (YSSG), lithium aluminum hexafluoride (LiSAF), lithium calcium aluminum hexafluoride (LiCAF), zinc selenium (ZnSe), ruby, forsterite, and sapphire. Example embodiments of dopants include neodymium (Nd), titanium (Ti), chromium (Cr), iron (Fe), erbium (Er), holmium (Ho), thulium (Tm), ytterbium (Yb), dysprosium (Dy), cerium (Ce), gadolinium (Gd), samarium (Sm), and terbium (Tb). Example embodiments of solid crystals include ruby, alexandrite, chromium fluoride, forsterite, lithium fluoride (LiF), sodium chloride (NaCl), potassium chloride (KC1), and rubidium chloride (RbCl). Laser diodes can comprise heterojunction or PIN diodes with three or more materials for the respective p-type, intrinsic, and n-type semiconductor layers. Example embodiments of laser diodes include AlGalnP, AlGaAs, InGaN, InGaAs, InGaAsP, InGaAsN, InGaAsNSb, GalnP, GaAlAs, GalnAsSb, and lead (Pb) salts. Some laser diodes can represent exemplary embodiments because of their size, tunable output power, and ability to operate at room temperature (i.e., about 20°C to about 25°C). As described below, fiber lasers comprise an optical fiber further comprising a cladding with any of the materials listed above for crystal lasers or laser diodes. [0068] The laser 601 is configured to emit a laser beam 301 (see FIG. 3) comprising a wavelength. The laser 601 may be operated such that the wavelength of the laser beam 301 is reduced by half (i.e., frequency doubled), reduced by two-thirds (i.e., frequency tripled), reduced by three-fourths (i.e., frequency quadrupled), or otherwise modified relative to a natural wavelength of a laser beam 301 produced by the laser 601. In some embodiments, the wavelength of the laser beam 301 may be about 760 nanometers (nm) or more, about 900 nm or more, about 980 nm or more, about 5,000 nm or less, about 4,000 nm or less, about 3,000 nm, or less, about 1,700 nm or less, about 1,660 nm or less, about 1,570 nm or less, about 1,330 nm or less, or about 1, 100 nm or less. In some embodiments, the wavelength of the laser beam 301 may be in a range from about 760 nm to about 5,000 nm, from about 760 nm to about 4,000 nm, from about 760 nm to about 3,000 nm, from about 760 nm to about 1,700 nm, from about 760 nm to about 1,660 nm, from about 760 nm to about 1,570 nm, from about 760 nm to about 1,330 nm, from about 760 nm to about 1,100 nm, from about 900 nm to about 5,000 nm, from about 900 nm to about 4,000 nm, from about 900 nm to about 3,000 nm, from about 900 nm to about 1,700 nm, from about 900 nm to about 1,660 nm, from about 900 nm to about 1,570 nm, from about 900 nm to about 1,330 nm, from about 900 nm to about 1,100 nm, from about 980 nm to about 5,000 nm, from about 980 nm to about 4,000 nm, from about 980 nm to about 3,000 nm, from about 980 nm to about 1,700 nm, from about 980 nm to about 1,660 nm, from about 980 nm to about 1,570 nm, from about 980 nm to about 1,330 nm, or from about 980 to about 1, 100 nm. Exemplary embodiments of a laser diode capable of producing a laser beam 301 with a wavelength within the aforementioned ranges include an AlGaAs, an InGaAsP, an InGaAsN laser diode. Exemplary embodiments of a laser 601 (other than a diode laser) capable of producing a laser beam 301 with a wavelength within the aforementioned ranges include a He-Ne gas laser, an Ar gas laser, an iodine excimer laser, a Nd doped YAG solid-state laser, a Nd doped YLF solid-state laser, a Nd doped YAP solid-state laser, a Ti doped sapphire solid-state laser, a Cr doped LiSAF solid-state laser, a chromium fluoride solid-state laser, a forsterite solid-state laser, a LiF solid-state laser, and a NaCl solid-state laser. Exemplary embodiments of a laser 601 that can produce a laser beam 301 with a wavelength within the aforementioned ranges when frequency-doubled include a XeNe gas laser, a HF gas laser, a Ho doped YAG solid-state laser, an Er doped YAG solid-state laser, a Tm doped YAG solid-state laser, a KC1 solid-state laser, a RbCl solid-state laser, and an AlGaln laser diode. Exemplary embodiments of a laser 601 that can produce a laser beam 301 with a wavelength within the aforementioned ranges when frequency-tripled include a HeNe gas laser, a DF gas laser, and a Pb salt laser diode.

[0069] As shown in FIGS. 3 and 5, the heating apparatus 226a, 226b can also comprise an optical fiber 305. The optical fiber 305 can comprise a first end 607 (see FIGS. 2 and 4) and a second end 306 (see FIGS. 2-5) opposite the first end 607. Throughout the disclosure, the length of an optical fiber is defined as the distance between a first point at the first end 607 of the optical fiber 305 and a second point at the second end 306 of the optical fiber 305 when the optical fiber 305 is straightened so that it is aligned with an elongated axis and the first point and the second point are as far apart as possible. Referring to FIGS. 6 and 7, in some embodiments, the optical fiber 305 can comprise a plurality of optical fibers 305a-i that can each include a length defined as the distance between the first end 607a-i of the optical fiber 305a-i and a second end 306a-i of the optical fiber 305a-i when the optical fiber 305a-i is straightened so that it is aligned with an elongated axis. In some embodiments, the length of the optical fiber 305 (e.g., the length of an optical fiber of the plurality of optical fibers 305a-i) may be about 100 mm or more, about 1 m or more, about 2 m or more, about 5 m or more, about 2,000 m or less, about 50 m or less, about 30 m or less, about 20 m or less, or about 10 m or less. In some embodiments, the length of the optical fiber 305 may be in a range from about 100 mm to about 2,000 m, from about 100 mm to about 50 m, from about 100 mm to about 30 m, from about 100 mm to about 20 m, from about 100 mm to about 10 m, from about 1 m to about 2,000 m, from about 1 m to about 50 m, from about 1 m to about 30 m, from about 1 m to about 20 m, from about 1 m to about 10 m, from about 2 m to about 30 m, from about 2 m to about 20 m, from about 2 m to about lOm, or from about 5 m to about 10 m. In some embodiments, all the optical fibers 305a-i of the plurality of optical fibers may comprise substantially the same length. In other embodiments, at least one of the optical fibers of the plurality of optical fibers may comprise a different length than another optical fiber of the plurality of optical fibers.

[0070] The optical fiber 305 (e.g., each optical fiber of the plurality of optical fibers 305a-i) can comprise a core (i.e., center) comprising an optical material. Throughout the disclosure, a width of the core of an optical fiber is defined as a distance between a first point at a second end of the optical fiber and a second point at the second end of the optical fiber, where the first point and the second point comprise the same material as the center of the second end of the fiber and the first point and the second point are as far apart as possible. For example, the width of the core of an optical fiber can be equal to the diameter when the core of the second end of the optical fiber is circular. When the core of the second end of the optical fiber is elliptical, the width is equal to twice the semi-major axis. In some embodiments, the width of the core of the optical fiber 305 can be about 1 pm or more, about 5 pm or more, about 9 pm or more, about 50 pm or more, about 62.5 pm or more, about 550 pm or less, about 490 pm or less, about 400 pm or less, about 360 pm or less, about 255 pm or less, or about 145 pm or less ln some embodiments, the width of the core of the optical fiber 305 can be in a range from about 1 pm to about 550 pm. from about 1 pm to about 490 pm, from about 1 pm to about 400 pm, from about 1 pm to about 360 pm, from about 1 pm to about 255 pm, from about 1 pm to about 145 pm, from about 5 pm to about 550 pm, from about 5 pm to about 490 pm, from about 5 pm to about 255 pm, from about 9 pm to about 550 pm, from about 9 pm to about 490 pm, from about 9 pm to about 400 pm, from about 9 pm to about 360 pm, from about 9 pm to about 250 pm, from about 9 pm to about 144 pm, from about 50 pm to about 550 pm, from about 50 pm to about 490 pm, from about 50 pm to about 400 pm, from about 50 pm to about 144 pm, from about 62.5 pm to about 550 pm, from about 62.5 pm to about 550 pm, from about 62.5 pm to about 490 pm, from about 62.5 pm to about 400 pm, from about 62.5 pm to about 360 pm, from about 62.5 pm to about 255 pm, from about 62.5 pm to about 150 pm.

[0071] In some embodiments, the optical material in the core of the optical fiber 305 (e.g., each optical fiber of the plurality of optical fibers 305a-i) may comprise sapphire, fused silica, quartz, or a combination thereof. In further embodiments, the optical material may be doped with an optical amplifier such as erbium (Er), ytterbium (Yb), neodymium (Nd), or germanium dioxide (Ge0₂). In some embodiments, the optical fiber 305 may comprise a cladding surrounding the core. In further embodiments, the cladding may comprise a lower refractive index than a refractive index of the core. In even further embodiments, the cladding may comprise fused silica, quartz, sapphire, or gas, for example air, nitrogen, or argon. In other even further embodiments, the cladding may comprise any of the material listed above for laser diodes or crystal lasers. Doping, cladding, or a combination of the two may be desirable to modify the amplitude of a laser beam 301 being transmitted by the optical fiber 305 (i.e., the optical fiber may be a fiber laser). In some embodiments, the core of the optical fiber 305 may comprise a circular cross-section. An optical fiber with a core comprising a circular cross-section can provide the laser beam 301 exiting the second end 306 of the optical fiber 305 with a smooth (i.e., homogenous and symmetric) intensity profile. In some embodiments, the first end 607 of the optical fiber 305 may comprise a circular cross-section, and the second end 306 of the optical fiber 305 may comprise a circular cross-section. Providing the optical fiber 305 with a circular cross-section can, in some embodiments, be used with a passage 307 and/or tube 309 with a circular cross-section.

[0072] As shown in FIGS. 6 and 7, in some embodiments, the laser 601 can comprise a plurality of lasers 601a-i (see FIG. 6) or a plurality of lasers 601a-f (see FIG. 7). As shown in FIG. 6, each laser of the plurality of lasers 601a-i can be optically coupled to the first end 607a-i of the respective optical fiber 305a-i. As such, at least some of a laser beam 301 generated by each corresponding laser of the plurality of lasers 601 a-i can be transmitted into the first end 607a-i of the optical fiber 305a-i, through the length of the optical fiber 305a-i, and out the second end 306a-i of the corresponding optical fiber of the plurality of optical fibers 305a-i. In some embodiments, each laser of the plurality of lasers 601a-i can coupled to each corresponding first end 607a-i of the optical fiber of the plurality of optical fibers 305a-i without a lens or other optics positioned therebetween. In other embodiments, a lens or other optical component can be placed between the laser 601 a-i and the first end 607a-i of the optical fiber 305a-i to direct the laser beam 301 to the core (i.e., center) of the first end 607a-i of the optical fiber 305a-i. It can be desirable to direct the laser beam 301 to the core of the first end 607a-i of the optical fiber 305a-i, which can reduce an attenuation (i.e., loss of intensity) of the laser beam 301 while the laser beam 301 is transmitted from the first end 607a-i to the second end 306a-i of the optical fiber 305a-i. A focal length of the lens can be chosen to desirably couple the laser beam 301 from the laser 601a-i into the first end 607a-i of the optical fiber 305a-i based on properties (e.g., a diameter of a portion of the core, a numerical aperture) of the optical fiber 305a-i, and properties (e.g., divergence) of the laser 601a-i, and the distance from the laser 601a-i to the lens as well as the distance from the lens to the first end 607a-i of the optical fiber 305a-i. In further embodiments, the lens may be a spherical lens, which can be desirable if the laser 601a-i (e.g., a laser diode) generates a homogenous (i.e., no astigmatism) laser beam 301. In other further embodiments, the lens may be aspheric (e.g., elliptical) correct any astigmatism of the laser beam 301. In some embodiments, as shown in FIG. 7, optically coupling the laser beam 301 to the first end 607a-i of the optical fiber 305a-i may comprise a beam splitter 705a-c and a relay fiber 707a-c, as discussed below. In some embodiments, the distance of the lens to the first end 607a-i of the optical fiber 305a-i may be varied to control a fraction of the laser beam 301 coupled into the optical fiber 305a-i. In some embodiments, the optical fibers 305a-i can comprise single-mode optical fibers. In some embodiments, the optical fibers 305a-i can comprise multi -mode fibers.

[0073] In some embodiments, as shown in FIGS. 3 and 5-9, the optical fiber 305 can extend into the passage 307 in the housing 218. In further embodiments, the optical fiber 305 can extend fully through the housing 218 in the passage 307, as illustrated by optical fiber 305e in FIG. 7. In even further embodiments, the optical fiber 305 can extend fully through the tube 309 in the passage 307, as further illustrated by optical fiber 305e in FIG. 7. In other further embodiments, as shown in FIGS. 2-5, the optical fiber 305 can partially extend through the tube 309 in the passage 307. For instance, as shown in FIG. 7, the optical fibers 305a-d and 305f-i only extend partially through the tube 309. In other embodiments, although not shown, the optical fiber 305 may partially extend through the tube 309 in a portion of the tube 309 outside of the passage 307. In still other embodiments, although not shown, the optical fiber 305 may not extend into the passage 307 in the housing 218 at all with only the laser beam 301 being transmitted through the passage 307 in the housing 218. It is to be understood that the position of the optical fiber 305 relative to the passage 307 in the housing 218 can be used in combination with either the embodiments shown in FIGS. 6 and 8, where the second material surrounds the passage 307 and extends away from the passage 307 for a distance, or the embodiments shown in FIGS. 7 and 9, where the tube 309 inside the passage 307 comprises a second material and the material surrounding the passage 307 comprises a first material.

[0074] In some embodiments, as shown in FIGS. 3 and 5, the tube 309 may be held in place by a faceplate 311 and/or the faceplate 311 may act to cap the passage 307 to minimize heat loss through the passage 307. The faceplate 311 may be connected to the outer surface 223 of the housing 218 by a fastener 313 or other attachment device. In some embodiments, the fastener 313 can comprise a rivet, a nail, a screw, a bolt, a snap, a clasp, a buckle, a hook-and-loop fastener, a latch, a cable tie, a strap, a pin, or a peg. Additionally, the faceplate 311 may act to minimize thermal loss from any space between an interior surface of the tube 309 and the surface of the passage 307 in the housing 218. In some embodiments, as shown in FIGS 6 and 7, the faceplate 311 may comprise a plurality of faceplates 311a-i for each corresponding passage 307a-i and/or corresponding tube 309a-i. In other embodiments, although not shown, a single faceplate may extend across all passages associated with a heating apparatus (e.g., 226a, 226b).

[0075] The optical fiber 305 can be positioned so that the second end 306 of the optical fiber 305 faces the molten material travel path 229. In some embodiments, as shown in FIGS. 2-7, the optical fiber 305 partially extends through the passage 307. In some embodiments, although not shown, the optical fiber 305 faces the passage 307 but does not extend into the passage 307. In some embodiments, although not shown, an optical fiber 305 may fully extend through the passage 307 and protrude beyond the inner surface 222 of the housing 218 into the interior 221. In some embodiments, an optical element may be placed between the second end 306 of the optical fiber 305 and the molten material travel path 229. In some embodiments, a distance between the second end 306 of the optical fiber 305 and the optical element may be fixed by attaching the optical element to a transparent material (e.g., a material suitable to be used as the core of the optical fiber 305) and the second end 306 of the optical fiber 305, where a refractive index of the transparent material is about the same or less than a refractive index of the core of the optical fiber 305. In other embodiments, a distance between the second end 306 of the optical fiber 305 and the optical element may be variable. For example, the optical element may be attached to an end of the passage 307 closest to the interior 221 of the housing 218 while the optical fiber 305 can be moved independently in the passage 307. An exemplary optical element may be a collimating lens, which acts to control the divergence of a laser beam 301 exiting the second end 306 of the optical fiber 305. In some embodiments, the collimating lens may be spherical, elliptical, or cylindrical. In some embodiments, there may be more than one lens as part of the optical element.

[0076] A power density and/or size of the laser beam 301 impinging on a portion of the molten material 121 on the molten material travel path 229 can be achieved in a wide range of ways such as one or more of: adjusting a position of the second end 306 of the optical fiber 305, the type of optical element, or a position of the optical element. Throughout the disclosure, a width of a laser beam 301 impinging on a portion of molten material 121 is defined as the distance in a direction across a molten material travel path 229 (i.e., perpendicular to the draw direction 154 and parallel to a draw plane 213) between a first point on the molten material 121 impinged by the laser beam 301 and a second point on the molten material 121 impinged by the laser beam 301 with an intensity of about 13.5 % (i.e., l/e²) of a maximum intensity of the laser beam 301 at a location on the molten material 121, where the first point and the second point are as far apart as possible in the direction across the molten material travel path 229. In some embodiments, the maximum width of the laser beam 301 can be about 100 pm or more, about 200 pm or more, about 500 pm or more, about 1 mm or more, about 2 mm or more, about 5 mm or more, about 10 mm or more, about 30 mm or less, about 20 mm or less, or about 15 mm or less. In some embodiments, the maximum width of the laser beam 301 can be in a range from about 100 pm to about 30 mm, from about 100 pm to about 20 mm, from about 100 pm to about 15 mm, from about 200 pm to about 30 mm, from about 200 pm to about 20 mm, from about 200 pm to about 15 mm, from about 500 pm to about 30 mm, from about 500 pm to about 20 mm, from about 500 pm to about 15 mm, from about 1 mm to about 30 mm, from about 1 mm to about 20 mm, from about 1 mm to about 15 mm, from about 2 mm to about 30 mm, from about 2 mm to about 20 mm, from about 2 mm to about 15 mm, from about 5 mm to about 30 mm, from about 5 mm to about 20 mm, from about 5 mm to about 15 mm, from about 10 mm to about 30 mm, from about 10 mm to about 20 mm, or from about 15 mm to about 20 mm. Throughout the disclosure an area of the molten material 121 impinged by a laser beam 301 is defined as a portion of the molten material 121 impinged by the laser beam 301 with an intensity of about 13.5 % (i.e., l/e²) of a maximum intensity of the laser beam 301, where the area is measured at a surface of the molten material 121 closest to the second end 306 of the optical fiber 305.

[0077] Throughout the disclosure, the power of a laser beam 301 is the average power of the laser beam 301 transmitted from a second end 306 of an optical fiber 305 as measured using a thermopile. In some embodiments, a power of the laser beam 301 can be controlled by controlling optical elements between the laser 601 and the second end 306 of the optical fiber 305. In some embodiments, a power of the laser beam can be controlled by adjusting the parameters of the laser (e.g., electrical current or voltage, optical pumping conditions). Throughout the disclosure, a power density of a laser beam 301 is the power of the laser beam 301 divided by the area of the molten material 121 impinged by the laser beam 301, as defined above. In some embodiments, the power density of the laser beam 301 can be about 1 watt/centimeter² (W/cm²) or more, about 2 W/cm² or more, about 5 W/cm² or more, about 10 W/cm² or more, about 20 W/cm² or more, about 2,000 W/cm² or less, about 1,000 W/cm² or less, about 500 W/cm² or less, about 200 W/cm² or less, about 100 W/cm² or less, or about 50 W/cm² or less. In some embodiments the power density of the laser beam 301 can be in a range from about 1 W/cm² to about 2,000 W/cm², from about 1 W/cm² to about 1,000 W/cm², from about 1 W/cm² to about 500 W/cm², from about 1 W/cm² to about 200 W/cm², from about 1 W/cm² to about 100 W/cm², from about 1 W/cm² to about 50 W/cm², from about 2 W/cm² to about 2,000 W/cm², from about 2 W/cm² to about 1,000 W/cm², from about 2 W/cm² to about 500 W/cm², from about 2 W/cm² to about 200 W/cm², from about 2 W/cm² to about 100 W/cm², from about 2 W/cm² to about 50 W/cm², from about 5 W/cm² to about 2,000 W/cm², from about 5 W/cm² to about 1,000 W/cm², from about 5W/cm² to about 500 W/cm², from about 5 W/cm² to about 200 W/cm², from about 5 W/cm² to about 100 W/cm², from about 5 W/cm² to about 50 W/cm², from about 10 W/cm² to about 2,000 W/cm², from about 10 W/cm² to about 1,000 W/cm², from about 10 W/cm² to about 500 W/cm², from about 10 W/cm² to about 200 W/cm², from about 10 W/cm² to about 100 W/cm², from about 10 W/cm² to about 50 W/cm², from about 20 W/cm² to about 2,000 W/cm², from about 20 W/cm² to about 1,000 W/cm², from about 20 W/cm² to about 500 W/cm², from about 20 W/cm² to about 200 W/cm², from about 20 W/cm² to about 100 W/cm², or from about 20 W/cm² to about 50 W/cm².

[0078] Throughout the disclosure, a target location is defined as a location to be impinged by a laser beam. Referring to FIG. 3, a target location 303a on the molten material 121 can be defined as a location where the laser beam 301 impinges on a portion of the molten material 121 as it travels along the molten material travel path 229. In some embodiments, as shown in FIGS. 2 and 3, the target location 303a on the molten material 121 may be elevationally above the root 145 of the forming vessel 140. In further embodiments, the laser beam 301 may impinge on a portion of the inclined converging surface 207a of the forming vessel 140 at a target location 303b on a surface of the forming vessel 140. In some embodiments, it can be desirable for the target location 303a to be above the root 145 of the forming vessel 140 because the molten material 121 typically moves slower than the molten material 121 below the root 145, which means that a portion of the molten material 121 may be impinged by the laser beam 301 longer when the target location 303a is above the root 145 than if the target location 303a is below the root 145. Further, it may be desirable for the target location 303a to be above the root 145 of the forming vessel 140 to correct a deviation in a thickness of a portion of the molten material 121 that is specific to the corresponding side of the forming vessel 140. For example, one of the weirs 203a, 203b of the forming vessel 140 may comprise an imperfection that produces a“streak” where the molten material is thicker than desired; heating the molten material 121 on the corresponding side of the forming vessel 140 at the outer surface 205a, 205b and/or the inclined converging portion 207a, 207b can ameliorate this“streak” before the molten material 121 converges at the root 145 and is drawn. Still further, it may be beneficial in some embodiments to provide the target location 303a above the root 145 to allow energy passing through the molten material to be captured by the forming vessel at the target location 303b. As such, the forming vessel may be heated further at target location 303b and/or the laser beam may be reflected from the forming vessel to further heat the portion of the molten material traveling over the second target location 303b while being directly heated by the laser beam 301 at the first target location 303a. Consequently, heating efficiency of heating the desired location of the molten material may be achieved in some embodiments by simultaneously directly heating the molten material 121 at the first target location 303a with the laser beam 301 while also further indirectly heating the molten material 121 with the portion of the forming vessel heated by the laser beam 301 and/or reflecting the laser beam from the forming vessel at the second target location 303b.

[0079] In other embodiments, as shown in FIG. 5, the laser beam 301 can impinge a portion of the molten material 121 at a target location 503 on the molten material 121 as it travels along the molten material travel path 229 below the root 145 of the forming vessel 140. It can be desirable for the laser beam 301 to impinge a target location 503 below the root 145 of the forming vessel 140.

[0080] In some embodiments, as shown in FIGS. 3 and 5, the laser beam 301 of the first heating apparatus 226a may be parallel with the laser beam 301 of the second heating apparatus 226b. In other embodiments, although not shown, the laser beam 301 of the first heating apparatus 226a may not be parallel with the laser beam of the second heating apparatus 226b. In some embodiments, as shown in FIG. 3, the laser beam 301 of the first heating apparatus 226a and the laser beam 301 of the second heating apparatus 226b may impinge on portions of the molten material 121 that may be at the same elevational position on the draw plane 213. In other embodiments, as shown in FIG. 5, the laser beam 301 of the first heating apparatus 226a and the laser beam 301 of the second heating apparatus 226b may impinge on portions of the molten material 121 that may be at different elevational positions on the draw plane 213. It is to be understood that any of the arrangements of the laser beam 301 of the first heating apparatus 226a may be parallel with the laser beam 301 of the second heating apparatus 226b can be used in combination with embodiments where the target location 303a is above the root 145 of the forming vessel 140, the target location 503 is below the root of the forming vessel, or a hybrid of these embodiments where the laser beam 301 of the first heating apparatus 226a impinges a target location 303a above the root 145 of the forming vessel 140 and the laser beam 301 of the second heating apparatus 226b impinges a target location 503 below the root 145 of the forming vessel. Further, it is to be understood that either position of the target location 303a, 503 relative to the root 145 of the forming vessel can be used in combination with the position of the optical fiber 305 relative to the passage 307 in the housing 218 discussed above as well as with either the embodiments shown in FIGS. 6 and 8, where the second material surrounds the passage 307 and extends away from the passage 307 for a distance, or FIGS. 7 and 9, where the tube 309 inside the passage 307 comprises a second material and the material surrounding the passage 307 comprises a first material.

[0081] Throughout the disclosure, an angle of incidence is defined as an angle formed by an intersection of a plane defined by a surface of a molten material 121 at the target location 303 closest to a second end 306 of an optical fiber 305 and a line running through a center of the second end 306 of the optical fiber and a center of the target location 303 of the molten material 121 on the molten material travel path 229. In some embodiments, the angle of incidence can be about 70° or more, about 80° or more, about 85° or more, about 88° or more, about 90°, about 110° or less, 100° or less, about 95° or less, about 92° or less, or about 90°. In some embodiments, the angle of incidence can be in a range from about 70° to about 110°, from about 80° to about 100°, from about 85° to about 95°, from about 88° to about 92°. Throughout the disclosure an angle of incidence can be considered“about normal” when it is in a range from about 80° to about 100°, from about 85° to about 95°, from about 88° to about 92°, or about 90°. In some embodiments, the passage 307 may be inclined to make the angle of incidence about normal when the target location 303, discussed below, is above the root 145 of the forming vessel 140.

[0082] The molten material 121 may comprise an absorption depth at a wavelength of a laser beam 301. Throughout the disclosure, an absorption depth of a material is defined as thickness of the material at which an intensity (e.g., power, power density) of a laser beam 301 decreases to 36.8 % (i.e., l/e) of an initial intensity of the laser beam 301. Without wishing to be bound by theory, it is possible to estimate the absorption depth using the Beer-Lambert law, which predicts that intensity decreases exponentially with the thickness of the material divided by the absorption depth. For some materials, the absorption depth may change with temperature. Unless otherwise specified, absorption depth was measured at about l000°C. In some embodiments, the molten material 121 may comprise an absorption depth at a wavelength of the laser beam 301 of about 50 pm or more, about 100 pm or more, about 200 pm or more, about 500 pm or more, about 1,000 pm or more, about 2,000 pm or more, about 5,000 pm or more, about 10,000 pm or more, about 20,000 pm or more, about 50,000 pm or more, or about 500,000 pm or less. In some embodiments, the molten material 121 may comprise an absorption depth at a wavelength of the laser beam 301 in a range from about 50 pm to about 500,000 pm, from about 100 pm to about 500,000 pm, from about 200 pm to about 500,000 pm, from about 500 pm to about 500,000 pm, from about 1,000 pm to about 500,000 pm, from about 2,000 pm to about 500,000 pm, from about 5,000 pm to about 500,000 pm, from about 10,000 pm to about 500,000 pm, from about 20,000 pm to about 500,000 pm, or from about 50,000 pm to about 500,000 pm. It can be desirable for the absorption depth to be greater than the thickness of the molten material so that the entirety of the molten material in the portion where the laser beam 301 impinges is heated by the laser beam 301.

[0083] FIG. 10 illustrates the temperature profile as a function of distance for different combinations of materials using an exemplary embodiment in accordance with the disclosure. The hormonal axis (x-axis) represent a position across (i.e. perpendicular to) the draw direction along the molten material travel path. The vertical axis (y-axis) represents a surface temperature of the material. The center of the target location of the laser beam corresponds to a point on the x-axis where the curves 1001, 1003, 1005 have a maximum value on the y-axis. In this example, the molten material is a substantially alkali-free aluminosilicate material, the molten material is moving at a speed of about 10 mm/s in the draw direction, and the wavelength of the laser beam 301 is about 976 nm. The conditions are identical for all curves other than whether the target location is above or below the root and whether the temperature plot is of the molten material or the forming vessel. The curve 1001 marked with diamonds shows the temperature profile of the molten material when the target location is below the root of the forming vessel. The curve 1003 marked with squares shows the temperature profile of the forming vessel when the target location is above the root of the forming vessel. The curve 1005 marked with triangles shows the temperature profile of the molten material when the target location is above the root of the forming vessel. The curves 1001, 1003, 1005 show that heating is localized at the target location and that the temperature profile is substantially symmetric across the x-axis (i.e., across the draw direction). The temperature increase of the molten material from the center of the target location relative to a baseline of the temperature profile is greater when the target location is above the root of the forming vessel as indicated by curve 1005 than when the target location is below the root of the forming vessel as indicated by curve 1001. Consequently, an increase in efficiency of heating the target area can be achieved by locating the target location elevationally above the root 145 of the forming wedge 209 as indicated by comparing the increased heating achieved by curve 1005 when compared to the heating achieved by curve 1001.

[0084] In some embodiments, as shown in FIGS. 6-9, the optical fiber 305 may comprise the plurality of optical fibers 305a-i. In some embodiments, there may be 1 or more, 2 or more, 4 or more, 9 or more, 16 or more, 24 or more, 100 or less, 50 or less, 40 or less, or 30 or less optical fibers in the plurality of optical fibers 305a-i. In some embodiments, the number of optical fibers in the plurality of optical fibers 305a-i can be from 1 to 100, from 1 to 50, from 1 to 40, from 1 to 30, from 2 to 100, from 2 to 50, from 2 to 40, from 2 to 30, from 4 to 100, from 4 to 50, from 4 to 40, from 4 to 30, from 9 to 100, from 9 to 50, from 9 to 40, from 9 to 30, from 16 to 100, from 16 to 50, from 16 to 40, from 16 to 30, from 24 to 100, from 24 to 50, from 24 to 40, or from 24 to 30. Each optical fiber of the plurality of optical fibers comprises a respective first end 607 and a second end 306. In some embodiments, the second end 306 of each optical fiber of the plurality of optical fibers 305a-i may be arranged in an array in a first direction transverse to the molten material travel path 229 (i.e., perpendicular to the draw direction 154) so that each second end 306 of the plurality of optical fibers 305a-i faces the molten material travel path 229. In further embodiments, as shown in FIG. 8 and 9, the plurality of optical fibers 305a-i may be staggered in a direction perpendicular to the first direction. In some embodiments, as shown in FIGS. 8 and 9, the plurality of optical fibers 305a-i may be arranged into more than one row. In some embodiments, the cross-sectional passage area of the passage 307 discussed above may apply to each passage of a plurality of passages that can each have an optical fiber of the plurality of optical fibers 305a-i and optionally a tube 309 extending at least partially through the corresponding passage 307.

[0085] In some embodiments, as shown in FIGS. 6 and 7, the laser 601 may comprise a plurality of lasers 601a-i (FIG. 6) or a plurality of lasers 601a-f (FIG. 7). In some embodiments, there may be 1 or more, 2 or more, 4 or more, 9 or more, 100 or less, 50 or less, 40 or less, 30 or less, or 20 or less lasers in the plurality of lasers. In some embodiments, the number of lasers in the plurality of lasers can be from 1 to 100, from 1 to 50, from 1 to 40, from 1 to 30, from 1 to 20, from 2 to 100, from 2 to 50, from 2 to 40, from 2 to 30, from 2 to 20, from 4 to 100, from 4 to 50, from 4 to 40, from 4 to 30, from 4 to 20, from 9 to 100, from 9 to 50, from 9 to 40, from 9 to 30, or from 9 to 20. In some embodiments, as shown in FIG. 6, the number of lasers in the plurality of lasers 601 a-i may be equal to the number of optical fibers in the plurality of optical fibers 305a-i, and each laser of the plurality of lasers 601 a-i can be optically coupled to a corresponding optical fiber of the plurality of optical fibers 305a-i. In other embodiments, as shown in FIG. 7, the number of lasers in the plurality of lasers 601 a-f can be less than the number of optical fibers in the plurality of optical fibers 305a-i. For example, a beam splitter 705a-c can allow a laser of the plurality of lasers 601 a-f to be optically coupled to more than 1 optical fiber of the plurality of optical fibers 305a-i as shown in FIG. 7. As shown, the beam splitter 705a-c may be optically coupled to a laser of the plurality of lasers 601 a-f through a relay fiber 707a- c. For example, the first end 607b of an optical fiber 305b of the plurality of optical fibers 305a-i can be optically coupled to a laser 601b of the plurality of lasers 601a-f because the corresponding laser 601b can be optically coupled to a relay fiber 707a optically coupled to a beam splitter 705a that can be further optically coupled to the first end 607b of the corresponding optical fiber 305b. In some further embodiments, all the optical fibers of the plurality of optical fibers 305a-i can be optically coupled to a single laser using a series of beam splitters. In other further embodiments, the number of beam splitters between a laser 601 and a first optical fiber of the plurality of optical fibers 305a-i can be different than the number of beam splitters between the laser 601 and a second optical fiber of the plurality of optical fibers 305a-i. In some embodiments, the power of a laser beam 301 transmitted through the first optical fiber may be one-half, one-quarter, one-eight, etc. the power of a laser beam 301 transmitted through the second optical fiber even though both optical fibers of the plurality of optical fibers 305a-i are optically coupled to the same laser 601. ln some embodiments, a first laser of the plurality of lasers may be different from a second laser of the plurality of lasers. In some embodiments, a laser beam 301 transmitted from a first laser of the plurality of lasers may comprise a different wavelength than another laser beam 301 transmitted from a second laser of the plurality of lasers. An exemplary embodiment of a beam splitter 705a-c can be a fiber optical coupler that acts as beam splitter 705a-c for a laser beam 301 within an optical fiber 305 or a relay fiber 707a-c. Other example embodiments of a beam splitter 705a-c can act on a laser beam 301 outside of an optical fiber 305 or a relay fiber 707a-c and comprise a metal- coated mirror (e.g., half-silvered mirror), or a pellicle, or a waveguide. It is to be understood that a beam splitter 705a-c can be used with any of the embodiments discussed above.

[0086] The glass manufacturing apparatus 100 comprising a laser 601 and an optical fiber 305 as described herein can be used in a method of manufacturing glass. First, molten material 121 can flow from the forming vessel 140 along the molten material travel path 229. Then, a laser beam 301 can be transmitted from the laser 601 into the first end 607 of the optical fiber 305. The laser beam 301 can propagate along the optical fiber 305 from the first end 607 of the optical fiber 305 to the second end 306 of the optical fiber 305. Further, the laser beam 301 can be transmitted from the second end 306 of the optical fiber 305 toward the molten material travel path 229. Then, the laser beam 301 can impinge a target location 303a, 303b, 503 while molten material 121 is flowing along the molten material travel path 229. The laser beam 301 can heat a portion of the molten material 121 that is at the target location 303a, 303b, 503. The laser beam 301 can also decrease a viscosity of a portion of the molten material 121 that is at the target location 303a, 303b, 503. In some embodiments, the target location 303a, 303b, 503 may be chosen by determining a portion of the molten material 121 comprising a thickness with a deviation from a predefined thickness, where the deviation is greater than a predetermined threshold. As such, heating the target location 303a, 303b, 503 can be achieved by impinging the laser beam 301 at the target location 303a, 303b, 503 to reduce a viscosity of the portion of the molten material 121 at the target location which can reduce the deviation of the thickness of the portion of the molten material 121 from the predefined thickness.

[0087] In some embodiments, as shown in FIGS. 6 and 7, the optical fiber 305 may comprise a plurality of optical fibers 305a-i that can be arranged as an array in a direction transverse to the molten material travel path 229, as described above ln further embodiments, each optical fiber of the plurality of optical fibers 305a-i can transmit a laser beam 301 from the corresponding second end 306 to impinge the target location(s) 303a, 303b, 503 with the plurality of laser beams 301. In some embodiments, there may be fewer laser beams impinging the target locations than there are optical fibers in the plurality of optical fibers 305a-i and/or lasers in the plurality of lasers because, for example, one or more lasers of the plurality of lasers is not operated and/or one or more optical fibers of the plurality of optical fibers 305a-i is not optically coupled to one or more lasers.

[0088] In some embodiments, a first laser beam impinging the molten material 121 at a first location may be different than a second laser beam impinging the molten material 121 at a second location, as described below ln some further embodiments, a first optical fiber of the plurality of optical fibers 305a-i that transmitted the first laser beam may have been moved closer to the molten material travel path 229 than a second optical fiber of the plurality of optical fibers 305a-i that transmitted the second laser beam. In some further embodiments, a first optical fiber (e.g., optical fiber 305e in FIG. 7) of the plurality of optical fibers 305a-i that transmitted the first laser beam may have been moved closer to the molten material travel path 229 than a second optical fiber of the plurality of optical fibers 305a-i that transmitted the second laser beam. In some further embodiments, a second optical fiber (e.g., optical fiber 305g in FIG. 7) of the plurality of optical fibers 305a-i that transmitted the second laser beam may have been moved away from the draw plane 213 along with the corresponding tube (e.g., tube 306g in FIG. 7). In other further embodiments, although not shown, a tube may protrude beyond the inner surface 222 of the housing 218 into the interior 221. In other further embodiments, optical components between the first optical fiber of the plurality of optical fibers 305a-i that transmitted the first laser beam and the molten material 121 may have been adjusted to change the width and/or height of the first laser beam incident on the molten material 121. In other further embodiments, a power of a first laser of the plurality of lasers that transmitted the first laser beam may have been decreased, as described above. In other further embodiments, optical components (e.g., beam splitter) between the first laser of the plurality of lasers that transmitted the first laser beam and the first optical fiber of the plurality of optical fibers 305a-i that transmitted the first laser beam may have been adjusted.

[0089] In some embodiments, as shown in FIG. 5, the target location 503 of the molten material 121 may be below the root 145 of the forming vessel 140. Consequently, a portion of the molten material 121 can comprise a glass ribbon 103 (see FIGS. 1-5) at the target location 503, and the laser beam 301 can heat the portion of the molten material 121 comprising the glass ribbon 103 (see FIGS. 1-5). As described above, the term“glass ribbon” is used to describe material below the root 145 of the forming vessel even when the material is not in a glassy state (i.e., above its glass transition temperature). In other embodiments, as shown in FIG. 2, the target location 303a can be above the root 145 of the forming vessel 140. In further embodiments, the laser beam 301 can heat a surface portion (e.g., a portion of the inclined surface 207a, 207b) of the forming vessel 140 at the second target location 303b, in addition to the target location 303a of the molten material 121. In even further embodiments, a portion of the laser beam 301 may reflect off the surface portion (i.e., a portion of the inclined surface 207a, 207b) of the forming vessel 140 at the target location 303b to heat the portion of molten material 121 at the target location 303a again, as demonstrated by the data presented in FIG. 10 discussed above.

[0090] As used herein the terms "the," "a," or "an," mean "at least one," and should not be limited to "only one" unless explicitly indicated to the contrary. Thus, for example, reference to "a component" includes embodiments having two or more such components unless the context clearly indicates otherwise.

[0091] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term“about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. If a numerical value or end-point of a range in the specification recites“about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by“about,” and one not modified by“about.” It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0092] The terms“substantial,”“substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a“substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, as defined above, “substantially similar” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially similar” may denote values within about 10% of each other, for example within about 5% of each other, or within about 2% of each other.

[0093] As used herein, the terms“comprising” and“including,” and variations t hereof, shall be construed as synonymous and open ended, unless otherwise indicated. A list of elements following the transitional phrases comprising or including is a non-exclusive list, such that elements in addition to those specifically recited in the list may also be present.

[0094] It should be understood that while various embodiments have been described in detail with respect to certain illustrative and specific examples thereof, the present disclosure should not be considered limited to such, as numerous modifications and combinations of the disclosed features are possible without departing from the scope of the following claims.

Claims

What is claimed is:

1. A glass manufacturing apparatus comprising: an optical fiber comprising a first end and a second end;

a laser optically coupled to the first end of the optical fiber; and

a molten material travel path, wherein the second end of the optical fiber faces the molten material travel path.

2. The glass manufacturing apparatus of claim 1, further comprising:

a housing comprising a wall defining an interior area, wherein the molten material travel path extends within the interior area of the housing and the optical fiber at least partially extends through a passage in the wall of the housing.

3. The glass manufacturing apparatus of claim 2, wherein the passage comprises a cross-sectional passage area perpendicular to an elongated axis of the optical fiber, wherein the cross-sectional passage area is in a range from about 0.01 millimeters² to about 500 millimeter².

4. The glass manufacturing apparatus of claim 2, wherein the passage comprises a cross-sectional passage area perpendicular to an elongated axis of the optical fiber, wherein the cross-sectional passage area is in a range from about 0.01 millimeters² to about 5 millimeter².

5. The glass manufacturing apparatus of any one of claims 1-4, further comprising a tube, the optical fiber at least partially extending through the tube.

6. The glass manufacturing apparatus of claim 5, wherein the tube comprises a ceramic material.

7. The glass manufacturing apparatus of any one of claims 1-6, further comprising a forming vessel, the second end of the optical fiber facing a target location below the forming vessel.

8. The glass manufacturing apparatus of any one of claims 1-6, further comprising a forming vessel, the second end of the optical fiber facing a target location on a surface of the forming vessel.

9. The glass manufacturing apparatus of any one of claims 1-8, wherein the laser is configured to emit a laser beam comprising a wavelength in a range from about 760 nanometers to about 5,000 nanometers.

10. The glass manufacturing apparatus of any one of claims 1-8, wherein the laser is configured to emit a laser beam comprising a wavelength in a range from about 760 nanometers to about 1,700 nanometers.

11. The glass manufacturing apparatus of any one of claims 1-10, wherein the laser comprises a laser diode.

12. The glass manufacturing apparatus of claim 11, wherein the laser diode comprises an AlGaAs laser diode, an InGaAsP laser diode, or an InGaAsN laser diode.

13. The glass manufacturing apparatus of any one of claims 1-12, wherein the optical fiber comprises a plurality of optical fibers comprising corresponding second ends facing the molten material travel path and arranged as an array in a direction transverse to the molten material travel path.

14. The glass manufacturing apparatus of any one of claims 1-13, where the optical fiber comprises sapphire, fused silica, or quartz.

15. A method of manufacturing glass with the glass manufacturing apparatus of claim 1, comprising:

flowing molten material along the molten material travel path;

transmitting a laser beam from the laser into the first end of the optical fiber; propagating the laser beam along the optical fiber from the first end of the optical fiber to the second end of the optical fiber;

transmitting the laser beam from the second end of the optical fiber;

impinging a target location of the molten material with the laser beam; and heating a portion of the molten material at the target location.

16. The method of claim 15, further comprising determining a deviation of a thickness of the portion of the molten material from a predefined thickness, wherein heating the target location with the laser beam decreases a viscosity of the portion of the molten material to reduce the deviation of the thickness of the portion of the molten material from the predefined thickness.

17. The method of claim 15 or claim 16, further comprising a forming vessel, wherein the target location of the molten material is positioned below the forming vessel, wherein the laser beam heats the portion of the molten material comprising a glass ribbon extending below the forming vessel.

18. The method of claims 15 or claim 16, further comprising a forming vessel, wherein the laser beam further impinges a surface of the forming vessel, the laser beam heating a portion of the surface of the forming vessel.

19. The method of any one of claims 15-18, wherein a wavelength of the laser beam is in a range from about 760 nanometers to about 5,000 nanometers.

20. The method of any one of claims 15-18, wherein a wavelength of the laser beam is in a range from about 760 nanometers to about 1,700 nanometers.

21. The method of any one of claims 15-20, wherein the laser beam impinging on the target location of the molten material comprises a power density in a range from about 1 watt/centimeter² to about 2,000 watts/centimeter².

22. The method of any one of claims 15-20, wherein the laser beam impinging on the target location of the molten material comprises a power density in a range from about 1 watt/centimeter² to about 200 watts/centimeter².

23. The method of any one of claims 15-22, wherein the laser comprises a laser diode.

24. The method of claim 23, wherein the laser diode comprises an AlGaAs laser diode, an InGaAsP laser diode, or an InGaAsN laser diode.

25. The method of any one of claims 15-24, wherein the laser beam impinging the target location of the molten material comprises an absorption depth of the molten material of about 50 micrometers or more.

26. The method of any one of claims 15-25, further comprising the laser beam impinging the target location of the molten material at an about normal angle of incidence.

27. The method of any one of claims 15-26, wherein a maximum width across the molten material travel path of the target location of the molten material impinged by the laser beam is in a range from about 100 micrometers to about 30 millimeters.

28. The method of any one of claims 15-27, wherein the second end of the optical fiber is moved relative to the molten material travel path.

29. The method of any one of claims 15-28, wherein the optical fiber comprises a plurality of optical fibers comprising corresponding second ends facing the molten material travel path and arranged as an array in a direction transverse to the molten material travel path, and impinging the target location of the molten material comprises impinging a plurality of locations of the molten material with respective laser beams.