CN103308976A - Optical fiber assembly and manufacturing method thereof - Google Patents

Abstract

A fiber optic assembly for hermetically sealing at least one optical fiber to an optical package is disclosed. The fiber optic assembly includes at least one optical fiber, an inner cylindrical portion, an outer tube portion configured to generally enclose the inner cylindrical portion, and a mounting mechanism for retaining the at least one optical fiber in a predetermined position within at least a portion of the fiber optic assembly. At least one optical fiber is hermetically sealed to the outer tube portion at one end of the outer tube portion. A method of manufacturing the fiber optic assembly is also disclosed. These components maintain the fiber in its predetermined alignment during all subsequent processes.

Description

Optical fiber assembly and method of manufacturing the same

technical field

The present invention relates to optical components and in particular, but not exclusively, to fiber optic assemblies for forming fiber optic lens arrays.

Background technique

In optical communication systems, information is transmitted via a carrier wave in the optical frequency band generated by a source such as a laser or a light emitting diode. Optical communication systems are more than adequate for traditional communication systems because of their significantly increased channel count and the ability to use materials other than expensive copper cables to transmit information. Optical fibers are common devices used to transport or guide waves in the optical frequency range from one point to another. The carrier in the optical frequency band is confined within the optical fiber while transmitting. To be useful, an optical fiber must have properties such as low optical transmission loss, low optical absorption, ease of fabrication, controllable refractive index, and high heat resistance.

In many applications, it is desirable to use multiple optical fibers in the communication path for a compact and cost-effective design. To achieve this goal, dual or multiple components can be combined into one package. Examples include dual pump lasers, dual detectors (PD), and balanced receivers. However, in dual components such as those described above, the two types of fiber need to be separately secured within a single package, and the above typically require two feedthrough ports. An optical package with multiple optical ports obviously increases alignment time and difficulty, and results in a larger package size for a single port package.

In addition to these problems, the fibers in multi-chip laser devices are randomly bent and aligned. In some cases, high alignment sensitivity requires the fiber to be perfectly aligned in all directions for best results. It is therefore very important to precisely align two or more fibers, as any misalignment will create alignment issues and therefore risk failure and long-term reliability.

Contents of the invention

In view of the foregoing background, it is an object of the present invention to provide alternative fiber optic assemblies and methods of manufacturing the same.

The above objects are achieved by the combination of features of the independent claims; the dependent claims disclose further advantages of embodiments of the invention.

Those skilled in the art can understand other objects of the present invention from the following description. Therefore, the above object statement is not exhaustive, but only serves to explain some of the above many objects of the present invention.

Accordingly, one aspect of the present invention relates to a fiber optic assembly for hermetically sealing at least one optical fiber to an optical package. The fiber optic assembly includes at least one optical fiber, an inner cylindrical portion, an outer tube portion configured to generally enclose the inner cylindrical portion, and a mounting mechanism for retaining the at least one optical fiber in a predetermined position within at least a portion of the fiber optic assembly. At least one optical fiber is hermetically sealed to the outer tube portion at one end of the outer tube portion.

In another aspect of the present invention, it relates to a method of manufacturing an optical fiber assembly, wherein the optical fiber assembly is used to seal at least one optical fiber to an optical package, the manufacturing method comprising the steps of: aligning at least one optical fiber at a predetermined position; Assembling an inner cylindrical portion and an outer tube portion around at least one optical fiber; the inner cylindrical portion is generally encapsulated by the outer tube portion; and hermetically sealing the at least one optical fiber to the outer tube portion.

There are many advantages to the present invention. One advantage is that in a fiber optic assembly as described in the present invention, the relative positions and orientations are predetermined, fixed and hermetically sealed in a single process in the fiber optic assembly. As an example, two optical fibers sealed and secured in accordance with the present invention will remain in their predetermined orientation and orientation during all subsequent handling. The two optical fibers so fixed will not bend or cross each other, thus preventing possible entanglement or damage of the two optical fibers.

In addition, embodiments of the present invention will maintain a certain predetermined gap between two optical fibers, wherein the gap is designed to match the distance (pitch) between the components that need to be aligned. Accordingly, the fiber optic assemblies of the present invention are suitable for most multiple component applications, including those where the distance between components is variable. Furthermore, by assembling two or more optical fibers together into an assembly, the size of the entire assembly can be minimized, especially compared to traditional designs where only two optical fibers are placed inside a metal tube. Accordingly, the fiber optic assembly design of the present invention results in a fiber optic assembly having the benefit of simple construction and low cost.

It should be appreciated that the present invention provides benefits for various fiber optic technology applications. One example is a fiber optic assembly adapted to cooperate with a semiconductor optics package. In this package, there are a plurality of semiconductor optical devices in one package, and a plurality of optical fibers through a single port of the package are connected to the plurality of semiconductor optical devices. Optical fibers hermetically sealed by the fiber optic assembly can thus be hermetically sealed to a single port of the semiconductor optics package in which the relative positions and orientations of the optical fibers are fixed. In this configuration, the application of high power lasers is possible while maintaining a small welding area and an economical design.

Description of drawings

The foregoing and other features of the invention will become apparent from the following description of a preferred embodiment, given by way of example only, when taken in conjunction with the accompanying drawings, in which:

Figure 1a shows the structure of a dual fiber optic assembly with grooved features according to one embodiment of the present invention;

Figure 1b is a cross-sectional view of the fiber optic assembly shown in Figure 1a taken along line A-A;

Figure 2 shows the construction of the outer tube portion suitable for the fiber optic assembly shown in Figure 1a;

Figure 3 shows the inner cylindrical portion of the fiber optic assembly shown in Figure 1a, wherein two optical fibers are held within the inner cylindrical portion;

Figure 4a shows the structure of a dual fiber optic assembly with dual bore features according to another embodiment of the present invention;

Figure 4b is a cross-sectional view of the fiber optic assembly shown in Figure 4a taken along line B-B;

Figure 5 shows a portion of the interior of the fiber optic assembly shown in Figure 4a;

Figure 6 shows an outer tube portion suitable for the fiber optic assembly shown in Figure 4a; and

Figure 7 shows the structure of a dual fiber optic assembly with dual inner hole features according to another embodiment of the present invention;

Figure 8a shows a cross-sectional view of the fiber optic assembly shown in Figure 7 along its radial direction;

Figure 8b is a cross-sectional view of the fiber optic assembly shown in Figure 8a taken along line A-A;

Figure 9 shows a flow chart of steps in a fiber optic assembly manufacturing process according to one embodiment of the present invention;

Figure 10 shows a flow chart of steps in a fiber optic assembly manufacturing process according to another embodiment of the present invention.

Detailed ways

Referring now to Figures 1a and 1b, one embodiment of a fiber optic assembly is shown. In this embodiment, fiber optic assembly 20 is used to seal two optical fibers to an optical component package. Two uncoated (or called bare) optical fibers 22 enter the optical fiber assembly 20 through one end of the optical fiber assembly 20 . In one embodiment, the uncoated fiber 22 is a lensed fiber capable of coupling directly to a laser component, such as a laser pump, at its end remote from the fiber assembly 20 . At a certain length, the uncoated optical fiber 22 entering the fiber optic assembly 20 is coated so as to have a protective sheath, and the protective sheath is removed at a portion closer to the lens side, where the coated optical fiber 24 passes through the fiber optic assembly 20. The other end leaves the fiber optic assembly 20 . The coated portion of optical fiber 24 extending from fiber optic assembly 20 is then used to transmit optical signals over physical distances and to enable connection to other external laser equipment. In one embodiment, the optical fiber is coated on portions of the optical fiber prior to assembly into the fiber optic assembly.

As shown in FIGS. 1a and 1b, fiber optic assembly 20 has a hypotube or outer tube portion 30, an inner cylindrical portion 28 disposed within outer tube portion 30, and an assembly mechanism (not shown). The hypotube is preferably a long metal tube with mechanical properties. The inner cylindrical portion 28 is secured to the outer tube portion 30 such that rotation of the inner cylindrical portion 28 relative to the outer tube portion 30 is prevented. In one embodiment, the inner cylindrical portion 28 is made of glass and the outer tube portion 30 is a metal tube, preferably made of Kovar. Kovar is an alloy of nickel, iron and cobalt.

As shown in FIGS. 1 b and 3 , two grooves 23 are formed on the circumference of the inner cylindrical portion 28 , and each uncoated optical fiber 22 is placed in a corresponding one of the grooves 23 . In a particular embodiment, the two grooves 23 are also referred to as fitting mechanisms in the fiber optic assembly 20 . Preferably, each groove 23 is in the shape of a letter V, and the inner angle and depth of the groove are designed to accommodate a specific type of coated optical fiber. In a preferred embodiment, two grooves 23 are located on the circumference of the inner cylindrical portion 28 along its diameter, wherein the two grooves 23 are symmetrical about the center of the inner cylindrical portion 28 (not shown). This enables the two uncoated optical fibers 22 to remain parallel within the fiber optic assembly 20 with a predetermined spacing between the two uncoated optical fibers 22 as the uncoated optical fibers 22 are relatively constrained with respect to each other by the inner cylindrical portion 28 . In other words, the positioning (orientation) and orientation of the optical fiber 22 is fixed by the groove 23 . In one embodiment, the spacing between uncoated fibers 22 is the same as the distance between semiconductor optics in a two-chip pump.

Returning to FIG. 1a, at the end of the fiber optic assembly 20 where the uncoated optical fiber 22 enters the fiber optic assembly 20, there is a hermetic seal 26 through which a portion of the uncoated optical fiber 22 is sealed to the outer tube portion 30. Preferably, the two uncoated optical fibers 22 are hermetically sealed to the outer tube part 30 at the aforementioned ends of the outer tube part 30 using glass or solder. Solder is used when bare optical fiber needs to be coated with metal in the soldered section prior to assembly. At the other end of the fiber optic assembly 20 where the coated portion of the optical fiber 24 exits the fiber optic assembly 20, the opening of the outer tube portion 30 is preferably sealed with epoxy. In this way, the inner cylindrical portion 28 is hermetically sealed (hermetically sealed) within the outer tube portion 30 and thus protected from the external environment.

Turning to FIG. 2, the outer tube portion 30 is shown primarily comprising two parts. It includes a narrower portion 34 and a wider portion 38 . The inner diameter of the wider portion 38 is greater than the inner diameter of the narrower portion 34 . The inner cylindrical portion 28 is configured to fit snugly within the narrower portion 34 . In other words, the optical fiber within the narrower portion 34 is in the form of the uncoated optical fiber 22 when the optical fiber within the narrower portion 34 is seated within the V-shaped groove of the inner cylindrical portion 28 . However, when the fiber extends from the narrower portion 34 to the wider portion 38, the uncoated fiber becomes a coated fiber (not shown). The inner diameter of the wider portion 38 therefore needs to be larger than the inner diameter of the narrower portion 34 in order to accommodate the increased diameter of the fiber due to the coating. The opening 36 of the outer tube portion 30 adjacent the narrower portion 34 can be used to apply glass/solder to hermetically seal the uncoated fiber as described above. As mentioned above, the remaining free space within the wider portion 38 is sealed with epoxy.

In the above-described embodiments, the uncoated portion 22 of the optical fiber is sealed to the outer tube portion 30 by using glass or solder. Since the outer tube portion 30 is made of metal, the entire fiber optic assembly 20 can be easily sealed to the optical component package. Additionally, the grooves on the inner cylindrical portion 28 ensure that the relative position of the uncoated optical fiber 22 remains constant within the fiber optic assembly.

In another embodiment of the present invention as shown in Figures 4a and 4b, the fiber optic assembly 120 has a double bore structure to confine the optical fiber therein. Here, components similar to those in FIGS. 1 a and 1 b are labeled with like reference numerals with a prefix "1". In this embodiment, fiber optic assembly 120 also includes outer tube portion 130, inner cylindrical portion 128, and an assembly mechanism (not shown). However, this embodiment differs from the first embodiment shown in Figures 1a and 1b in that the assembly mechanism of the fiber optic assembly is different from the previously described assembly mechanism. In the current embodiment, the fitting mechanism no longer includes a groove formed on the circumference of the inner cylindrical portion 128 . Instead, the assembly mechanism now includes a sleeve 134 formed in the inner cylindrical portion 128 as best shown in FIGS. 4b and 5 . The coated portion of the optical fiber 124 exits the fiber optic assembly 120 via the other end of the fiber optic assembly 120 . Uncoated optical fiber 122 is hermetically sealed to outer tube portion 130 with seal 126 in a similar manner as described above.

Figure 5 shows the mechanism of the inner cylindrical portion 128 of the structure in the embodiment shown in Figures 4a and 4b. The inner cylindrical portion 128 basically includes two portions, a restricting portion 136 and a sleeve portion 134 . Ferrule portion 134 includes two bores 129 through which each uncoated optical fiber 122 passes through a respective one of the two bores 129 . Restricted portion 136 has a wider end 139 and a narrower end 137 . In a preferred embodiment, restricting portion 136 is in the shape of a tapered tube. Narrower end 137 is coupled to the second end of sleeve portion 134 . Two uncoated optical fibers (not shown) enter fiber optic assembly 120 through a first end of ferrule portion 134 and extend through narrower end 137 to confinement portion 136 . The coated portions (not shown) of the two optical fibers then exit the fiber optic assembly via the wider end 139 of the restricting portion 136 .

Since the two holes disposed in the ferrule portion 134 are parallel to each other and spaced apart by a certain gap, the inner hole 129 also keeps the two uncoated optical fibers 122 parallel and spaced apart by a predetermined distance. In other words, the position and orientation of the optical fiber 122 is fixed by the bore 129 of the ferrule portion 134 . Similar to the above, the optical fiber within the ferrule portion 134 is in the form of the uncoated optical fiber 122 when the optical fiber within the ferrule portion 134 is located within the bore 129 of the ferrule portion 134 . However, when the fiber extends from ferrule portion 134 to confinement portion 136, the uncoated fiber becomes a coated fiber (not shown), which results in confinement portion 136 having a larger diameter than ferrule portion 134 in order to accommodate the The diameter by which the fiber diameter increases. As mentioned above, the remaining free space within the restricted portion 136 is sealed with epoxy.

FIG. 6 shows the shape of the outer tube portion 130 of the fiber optic assembly 120 . The opening 138 of the outer tube portion 130 can be used to apply glass/solder to hermetically seal the uncoated fiber as described above. It should be noted that the diameter of the cavity 140 of the outer tube portion 130 is uniform because in this embodiment the inner cylindrical portion 128 also has a uniform diameter along its longitudinal axis.

Returning to FIG. 4 a , the limiting member 132 is secured to the opposite end of the outer tube portion 130 to the other end that hermetically seals the two uncoated optical fibers 122 to the outer tube portion 130 . Preferably, the limiting member 132 is sealed to the opposite end using epoxy. It can be seen that a portion of the two coated optical fibers 124 passes through the restricting member 132, which thereby prevents the two coated optical fibers 124 from bending. Restricting components, also known as bend limiters, prevent flexible optical fibers from excessive bending at the interface between the fiber and fiber optic assembly. Depending on the application, the bend limiter can be made of a rigid material such as metal, or a resilient material such as rubber.

In another embodiment of the present invention as shown in FIG. 7, FIG. 8a and FIG. 8b, the fiber optic assembly 220 has a double bore structure to confine the fiber therein. Here, components similar to those in Figures 4a and 4b are labeled with like reference numerals with a "2" prefix. In this embodiment, fiber optic assembly 220 also includes outer tube portion 230, inner cylindrical portion 228, and an assembly mechanism (not shown). However, this embodiment differs from the second embodiment shown in FIGS. 4 a and 4 b in that the fitting mechanism for the two inner holes 129 is formed in the outer tube portion 230 instead of in the inner cylindrical portion 228 . The uncoated fiber (not shown) entering the fiber optic assembly 220 is partially coated, wherein the coated fiber (not shown) exits the fiber optic assembly 220 via the other end of the fiber optic assembly 220 . Uncoated optical fiber is sealed to outer tube portion 230 with a seal (not shown) in a similar manner to that described above.

8a and 8b, the outer tube part 230 mainly includes two hollow parts, namely a first cavity 240 and a second cavity (not shown). The outer tube portion 230 also includes two holes 229 formed in a circumferential portion of the outer tube portion 230 . In a preferred embodiment, each of the two holes 229 has an opening communicating with a second cavity (not shown). When the inner cylindrical part 228 is placed in the second cavity, the opening of the hole 229 is closed by a part of the circumference of the inner cylindrical part 228, as shown above in Fig. 8a. Each uncoated optical fiber (not shown) passes through a corresponding one of the two holes 229 . Two uncoated optical fibers (not shown) enter the fiber optic assembly 220 through the first end of the hole 229 and extend to the first cavity 240 through the second end of the hole 229 . Additionally, the opening 238 of the outer tube portion 230 can be used to apply glass/solder to hermetically seal the uncoated fiber as described above.

In one embodiment, the two inner holes disposed in the outer tube portion 230 are parallel to each other with a certain gap therebetween. In other words, the position and orientation of the optical fiber is fixed by the inner bore 229 of the outer tube portion 230 . Similar to the above, the optical fiber is in the form of an uncoated optical fiber within the inner bore 229 of the outer tube portion 230 . However, when the fiber extends from the bore 229 to the first cavity 240, the uncoated fiber becomes a coated fiber (not shown). The remaining free space in the first cavity 240 can be sealed with epoxy as described above.

Referring to Figure 9, there are shown steps in a method of manufacturing a fiber optic assembly for sealing at least two optical fibers to an optical package. The steps of such a method according to one embodiment are shown in FIG. 7 . The resulting fiber optic assembly is similar to that shown in Figures 4a, 4b. The method starts at step 200 where two optical fibers are provided. A portion of the fiber is in the form of an uncoated fiber that can be coupled directly to a two-chip pump. Another part of the fiber is in the form of coated fiber, which is suitable for laying over a certain physical distance. In step 202, two optical fibers are aligned parallel to each other and spaced apart from each other by a predetermined distance. The next step is then to assemble the inner cylindrical part and the outer tube part around the optical fiber, wherein the inner cylindrical part is generally encapsulated by the outer tube part. In step 204, the inner cylindrical portions of the bare uncoated portions of the two optical fibers are formed. For example, the inner cylindrical portion may be formed by transitioning glass solder around the optical fiber from a molten state to a solidified state. Accordingly, the ferrule portion is positioned such that the two optical fibers pass through the inner cylindrical portion, and the position and predetermined spacing of the two optical fibers are maintained by the rigid inner cylindrical portion. At step 206, the outer tube portion is coupled to the inner cylindrical portion, wherein the inner cylindrical portion is received within the outer tube portion. In one embodiment, the outer tube portion is a metal tube encapsulating the inner glass portion. At step 208, the uncoated portions of the two optical fibers are hermetically sealed to the outer tube portion such that the two optical fibers are sealed to the optical package when the outer tube portion is sealed to the external optical component package. Finally, at step 210, the opening of the outer tube portion adjacent to the coated optical fiber is preferably sealed with epoxy. Fiber optic assemblies with recessed features to confine uncoated fibers can also be fabricated using a method similar to that described above.

In one embodiment, a restricting member, preferably a rigid tube, is secured to the other end of the outer tube portion opposite the other end to which the two uncoated optical fibers are hermetically sealed to the outer tube portion. At step 210, the constraining member is attached to the fiber optic assembly using epoxy sealing.

Referring to FIG. 10 , a flowchart depicts steps in a method of manufacturing an optical fiber assembly for sealing at least one optical fiber in accordance with another embodiment of the present invention. The fiber optic assembly thus formed is similar to the one shown in Figures 8a and 8b. The method starts at step 300 where two optical fibers are provided. A portion of the optical fiber is manufactured by removing the plating and forming the end of the optical fiber as needed. Another part of the fiber is in the form of a coated fiber, which is suitable for deployment over a certain physical distance. At step 302, two optical fibers are positioned and spaced apart from each other by a predetermined distance. The next step is then to assemble the inner cylindrical part and the outer tube part around the optical fiber, wherein the inner cylindrical part is generally encapsulated by the outer tube part. At step 304, an outer tube portion is assembled around the two optical fibers. The outer tube part includes two inner holes, also known as the assembly mechanism of the fiber optic assembly. Preferably, similarly to Fig. 8a, two inner holes are formed in the circumferential portion of the outer tube part. The outer tube portion and thus the two inner bores are positioned such that each of the two optical fibers is placed within a respective one of the two bores. Thus, the two optical fibers pass through the outer tube portion, and the parallel position and predetermined spacing of the two optical fibers defined in the alignment step 302 are maintained by the rigid outer tube portion. At step 306, the inner cylindrical portion is inserted into the outer tube portion, whereby the inner cylindrical portion is generally encapsulated by the outer tube portion. In one embodiment, the outer tube portion is a metal tube encapsulating the inner glass portion. In step 308, the uncoated portions of the two optical fibers are hermetically sealed to the outer tube portion such that when the outer tube portion is sealed to the external optical component package to form a hermetically sealed seal, the two optical fibers are hermetically sealed to the optical package . Finally, at step 310, the opening of the outer tube portion adjacent to the coated optical fiber is preferably sealed with epoxy. Fiber optic assemblies with recessed features to confine uncoated fibers can also be fabricated using a method similar to that described above.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the foregoing is to be considered illustrative and not restrictive, it being understood that while only exemplary embodiments have been shown and described, the The above does not in any way limit the scope of the invention. It should be appreciated that any feature described herein can be used with any embodiment. Exemplary embodiments herein are not mutually exclusive of each other, or exemplary embodiments herein are not exclusive of other embodiments not cited herein. Accordingly, the present invention also provides embodiments comprising combinations of one or more of the above-described exemplary embodiments. Variations and modifications may be made to the foregoing presented herein without departing from the spirit and scope of the invention. Accordingly, such limitations should be imposed only as indicated by the appended claims.

It should be understood that, if any prior art publication is referred to herein, in Australia or any other country, such reference is not to be taken as constituting that publication forming part of the common general knowledge in the art.

In the above embodiments, the distance between two uncoated optical fibers in the fiber optic assembly can be adjusted according to the specific application of the fiber optic assembly. For example, the pitch can be designed such that two uncoated fibers can be precisely coupled to a 980 nm dual-chip pump. However, for those skilled in the art, the spacing between uncoated fibers within a fiber optic assembly can also be changed to other values depending on the laser component to which the uncoated fibers are coupled.

In order to hermetically seal the uncoated optical fiber to the outer tube portion, the embodiments described above use glass or solder. However, this is only shown as an exemplary embodiment and virtually any type of material suitable for the purpose of sealing an uncoated optical fiber may be used. Similarly, the opening of the outer tube portion may be sealed using a material other than epoxy as long as it provides the same or a similar effect.

In the embodiments described above and shown in the drawings, there are only two optical fibers within the fiber optic assembly, which are suitable for coupling to a two-chip pump. However, it should be appreciated by those skilled in the art that any number of optical fibers, such as one, three, four or five optical fibers, may be sealed in accordance with the spirit of the invention, depending on the particular application.

In the above, the fiber entering the fiber optic assembly is confined at the end of the fiber optic assembly adjacent to the uncoated fiber. The optical fiber exiting the fiber optic assembly is defined at that end of the fiber optic assembly adjacent to the coated optical fiber. However, the terms "entering" and "exiting" are only meant to better explain the preferred embodiment and should not be considered as limitations imposed on the present invention. For example, in some cases, the two ends of a fiber optic assembly where the fibers "enter" and "exit" the fiber optic assembly are interchangeable.

In the claims following the preceding description of the invention and in the foregoing description of the invention, the words "comprise" or words such as "comprises" or The variant of "comprising" is used in a broad sense, that is, the stated features are explicitly present, but it does not exclude the existence or addition of additional features in various embodiments of the present invention.

As used in this specification and claims, "coupled" or "connected" means directly or indirectly optically coupled or linked via one or more optical devices, unless otherwise stated.

Claims (39)

1. A fiber optic assembly for sealing at least one optical fiber to an optical package, the fiber optic assembly comprising: a) inner cylindrical part; b) an outer tube portion arranged to substantially encapsulate said inner cylindrical portion; c) an assembly mechanism for splicing said at least one optical fiber at a predetermined location within at least a portion of said fiber optic assembly; Wherein said at least one optical fiber is hermetically sealed to said outer tube portion at one end of said outer tube portion. 2. The fiber optic assembly of claim 1, wherein the at least one optical fiber is sealed to the optical package when the outer tube portion is sealed to the optical package. 3. The fiber optic assembly of claim 1 , wherein the assembly mechanism further comprises a ferrule portion formed within the inner cylindrical portion, the ferrule portion including at least one inner bore configured to configured to receive the at least one optical fiber passing through the bore. 4. The fiber optic assembly of claim 3, wherein the inner cylindrical portion further includes a restricting portion having a wider end and a narrower end; the narrower end being coupled to the ferrule portion second end; the at least one optical fiber enters the fiber optic assembly via the first end of the ferrule portion and extends to the restricting portion via the narrower end of the restricting portion; the at least one An optical fiber exits the fiber optic assembly via the wider end of the restricting portion; thereby, retaining the at least one optical fiber at the predetermined position within the inner cylindrical portion of the fiber optic assembly. 5. The fiber optic assembly of claim 4, wherein the restrictive portion is a tapered tube. 6. The fiber optic assembly of claim 3, wherein the fiber optic assembly includes two optical fibers and the ferrule portion includes two bores; the two bores are parallel to each other for retaining the at least two optical fibers parallel, and make a predetermined distance between any two of the at least two optical fibers. 7. The fiber optic assembly according to claim 1, wherein said assembly mechanism further comprises at least one groove formed on the circumference of said inner cylindrical portion; each of said at least one optical fiber is placed in said at least one optical fiber. corresponding one of the at least one groove. 8. The fiber optic assembly according to claim 7, wherein said fiber optic assembly comprises two optical fibers; two said grooves are formed on said circumference of said inner cylindrical portion; said two grooves hold two The two optical fibers are parallel, so that there is a predetermined distance between the two light rays. 9. The fiber optic assembly of claim 7, wherein the at least one groove is V-shaped. 10. The fiber optic assembly of claim 1 , wherein said assembly mechanism further comprises at least one inner bore formed in said outer tube portion; each of said at least one optical fiber is placed in said at least one optical fiber. within a corresponding one of the bores. 11. The fiber optic assembly of claim 10, wherein the at least one hole is formed in a circumferential portion of the outer tube portion. 12. The fiber optic assembly of claim 11, wherein the outer tube portion further includes a cavity within which the inner cylindrical portion is substantially encapsulated. 13. The fiber optic assembly of claim 12, wherein the at least one bore has an opening in communication with the cavity. 14. The fiber optic assembly of any one of claims 1-13, wherein the inner cylindrical portion is made of glass. 15. The fiber optic assembly of any one of claims 1-13, wherein the outer tube portion is a metal tube. 16. The fiber optic assembly of claim 15, wherein the outer tubular portion is made of Kovar. 17. The fiber optic assembly according to any one of claims 1-13, wherein said at least one optical fiber is in the form of a lensed fiber capable of coupling directly to a laser chip before entering said fiber optic assembly. 18. The fiber optic assembly of any one of claims 1-13, wherein the at least one optical fiber is plated prior to assembly into the fiber optic assembly. 19. The fiber optic assembly of any one of claims 1-13, further comprising a limiting member fixed to an opposite end of the outer tube portion, the end being hermetically sealed to the at least one optical fiber. The ends of the outer tube portion are opposite; a portion of the at least one optical fiber passes through the restricting member, whereby the restricting member prevents the portion of the at least one optical fiber from bending. 20. The fiber optic assembly of claim 19, wherein the limiting member is sealed to the opposite end. 21. The fiber optic assembly of claim 20, wherein the limiting member is sealed to the opposite end with epoxy. 22. A method of manufacturing an optical fiber assembly, wherein the optical fiber assembly is used to seal at least one optical fiber to an optical package, said method comprising the steps of: a) aligning said at least one optical fiber at a predetermined location; b) assembling an inner cylindrical portion and an outer tube portion around the at least one optical fiber; the inner cylindrical portion is substantially encapsulated by the outer tube portion; and c) hermetically sealing said at least one optical fiber to said outer tube portion. 23. The method of claim 22, wherein the at least one optical fiber is sealed to the optical package when the outer tube portion is sealed to the optical package. 24. The method of claim 22, wherein the fiber optic assembly further comprises a fitting mechanism; the assembling step further comprising positioning the fitting mechanism to splice the at least one optical fiber within at least a portion of the fiber optic assembly at the predetermined location. 25. The method of claim 24, wherein the assembly mechanism further comprises a sleeve portion formed within the inner cylindrical portion; the sleeve portion includes at least one inner hole; the assembling step further comprising The above steps: a) forming said inner cylindrical portion around said at least one optical fiber, wherein said sleeve portion is positioned such that said at least one inner bore is configured to receive said at least one optical fiber therethrough; b) coupling the outer tube portion to the inner cylindrical portion such that the outer tube portion substantially encapsulates the inner cylindrical portion. 26. The method of claim 25, wherein the inner cylindrical portion further comprises a restriction portion having a wider end and a narrower end; the narrower end being coupled to a second end of the sleeve portion. two ends; the at least one optical fiber enters the fiber optic assembly via the first end of the ferrule portion, and extends to the restricting portion via the narrower end of the restricting portion; the at least one optical fiber An optical fiber exits the fiber optic assembly via the wider end of the restricting portion; thereby retaining the at least one optical fiber at the predetermined position within the inner cylindrical portion of the fiber optic assembly. 27. The method of claim 26, wherein the restriction is a tapered tube. 28. The method of claim 25, wherein the fiber optic assembly includes two optical fibers and the ferrule portion includes two bores; the two bores are parallel to each other so as to keep the at least two optical fibers parallel , and make a predetermined distance exist between any two of the at least two optical fibers. 29. The method of claim 24, wherein said assembly mechanism further comprises at least one inner bore formed in said outer tube portion; said assembling step further comprising the step of: a) disposing the outer tube portion around the at least one optical fiber, wherein the at least one inner hole is positioned such that each of the at least one optical fiber is placed in a respective one of the at least one hole within; and b) inserting the inner cylindrical portion into the cavity of the outer tube portion, whereby the inner cylindrical portion is substantially encapsulated by the outer tube portion. 30. The method of claim 29, wherein the at least one inner bore is formed in a circumferential portion of the outer tube portion. 31. The method of claim 29, wherein the at least one bore has an opening in communication with the cavity. 32. The method of any one of claims 22-31, wherein the inner cylindrical portion is made of glass. 33. The method of any one of claims 22-31, wherein the outer tube portion is a metal tube. 34. The method of claim 33, wherein the outer tubular portion is made of Kovar. 35. The method of any one of claims 22-31, wherein the at least one optical fiber is coated prior to assembly into the fiber optic assembly. 36. The method of any one of claims 22-31, wherein said at least one optical fiber is in the form of a lensed optical fiber capable of coupling directly to a laser chip before entering said fiber optic assembly. 37. The method according to any one of claims 22-31, further comprising the step of attaching a confinement member to an opposite end of the outer tube portion that is hermetically sealed to the at least one optical fiber Said ends sealed to said outer tube portion are opposite; a portion of said at least one optical fiber is attached to said restricting member, whereby said restricting member prevents said portion of said at least one optical fiber from bending . 38. The method of claim 37, wherein the step of attaching further comprises sealing the limiting member to the opposite end. 39. The method of claim 38, wherein the step of attaching further comprises sealing the limiting member to the opposite end with epoxy.

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