JP2015135402A - Planar waveguide circuit with optical path change and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a planar waveguide circuit with optical path conversion that is easy to produce and has high accuracy. The method of manufacturing a planar waveguide circuit with optical path conversion according to the present invention is a planar waveguide optical path conversion mirror structure having a mirror angle that is easy to manufacture and has high accuracy and a mirror surface with a small surface roughness. I will provide a. Specifically, a planar waveguide circuit including an optical path conversion mirror can be provided by a wafer process. Therefore, it is not necessary to mount an optical path conversion mirror, and an integrated integrated module with a low manufacturing cost can be manufactured. [Selection] Figure 1

Description

  The present invention relates to a planar waveguide circuit with an optical path change and a manufacturing method thereof.

  In the optical communication field, an optical functional component is configured and integrated using a planar waveguide circuit. In order to perform optical communication using such a planar waveguide circuit, optical coupling for inputting light from the optical element to the planar waveguide circuit is required. In addition, optical coupling is required to extract part or all of the light from the planar waveguide circuit and input it to another optical element.

  In an integrated module such as a conventional integrated integrated reception front-end module, light output from the side surface of a planar waveguide circuit is received by an optical element disposed on the side surface without changing the optical path. In addition, light is input to the side surface of the planar waveguide circuit by an optical element. Examples of the optical element include laser diode (LD) and photo diode (PD). In order to reduce the size of the module, it is necessary to provide the module with an optical path changing function and to mount the optical element on the surface. Therefore, a vertical input / output structure has been proposed as an optical coupling structure between the planar waveguide circuit and the optical element. In the vertical input / output structure, an optical path changing mirror for converting the optical path is provided in a part of the planar waveguide circuit, and light is input / output in a direction perpendicular to the light traveling direction in the planar waveguide circuit. Therefore, if the optical element is surface-mounted and light is input / output from the optical element to a planar waveguide circuit having a vertical input / output structure, the module can be reduced in size. However, the mirror included in the planar waveguide circuit with an optical path conversion disclosed in Patent Document 1 includes processing by a laser or the like in the manufacturing process, and it has been difficult to produce with high accuracy. In addition, the mirror yield is not high.

  Therefore, a method of forming a mirror by forming a mirror support using a resin in a planar waveguide circuit formed on a substrate in Patent Document 2 and depositing a metal on the mirror support is proposed. . However, since the mirror support shown in Patent Document 2 uses a resin, it is inferior in heat resistance, and the mirror may be deformed depending on environmental conditions. Furthermore, since it has a process using a resin, there is a drawback that the cost increases.

Japanese Patent Laid-Open No. 11-153719 JP 2007-240781 A

  In order to solve the above-described problems, an object of the present invention is to provide a planar waveguide circuit with an optical path change and a manufacturing method thereof, which are low in manufacturing cost.

  In order to achieve the above object, the method for manufacturing a planar waveguide circuit with optical path conversion according to the present invention forms a mirror on a mirror support using a wafer process and anisotropic etching. The planar waveguide circuit with optical path conversion according to the present invention is a planar waveguide circuit with optical path conversion manufactured by the method for manufacturing a planar waveguide circuit with optical path conversion according to the present invention.

  Specifically, the method for manufacturing a planar waveguide circuit with optical path conversion according to the present invention is a planar waveguide having an optical path conversion function in which a mirror is provided in a planar waveguide circuit having a core, an upper cladding, and a lower cladding. A method for manufacturing a circuit, wherein at least a part of a mirror support disposed on a lower clad is subjected to anisotropic etching at least a part of the mirror support to form a slope for providing a mirror. A mirror support forming step, a mirror forming step of forming a mirror on at least a part of the slope, and a core on the lower clad and the part where the mirror support is not formed and the slope. A core forming step of forming a waveguide for guiding the light reflected by the mirror or a waveguide for guiding the light incident on the mirror, and laminating the upper clad on the mirror and the core. And a cladding formation step in this order.

  Since the mirror support body forming step and the mirror forming step are included, the mirror can be manufactured with high accuracy and high yield. Moreover, since it has a core formation process and an upper clad formation process, the manufacturing method of the planar waveguide circuit with an optical path change which has a mirror with a high precision and a high yield can be provided.

  Specifically, the method for manufacturing a planar waveguide circuit with optical path conversion according to the present invention is a planar waveguide having an optical path conversion function in which a mirror is provided in a planar waveguide circuit having a core, an upper cladding, and a lower cladding. A method for manufacturing a circuit, wherein at least a part of a mirror support disposed on a lower clad is subjected to anisotropic etching at least a part of the mirror support to form a slope for providing a mirror. A mirror support formation step, a waveguide on the lower clad and on which the mirror support is not formed and a core on the inclined surface, and guides the light reflected by the mirror, or A core forming step of forming a waveguide for guiding light incident on the mirror, an upper clad forming step of stacking an upper clad on the slope and on the core, and a core and an upper clad on the slope. And the waveguide hole forming step of removing may comprise a mirror forming step of forming a mirror on at least a part of the slope in order.

  Since the mirror support body forming step and the mirror forming step are included, the mirror can be manufactured with high accuracy and high yield. In addition, since it has a core formation process, an upper cladding formation process, and a waveguide hole formation process, it has a mirror with high accuracy and high yield, and furthermore, manufactures a planar waveguide circuit with optical path conversion with low optical loss during optical path conversion. Can provide a method.

  In the manufacturing method of the planar waveguide circuit with optical path conversion of the present invention, the inclined surface may be concaved by performing anisotropic etching of the mirror support while applying a voltage to the mirror support in the mirror support forming step. .

  In the method of manufacturing a planar waveguide circuit with optical path conversion according to the present invention, in the mirror support forming step, the mirror support is laminated so that the crystal plane of the mirror support is inclined with respect to the lower cladding, and the inclined surface is exposed. Etching may be performed as described.

  Specifically, the planar waveguide circuit with optical path conversion of the present invention has a lower clad layer disposed on a substrate and a crystal plane disposed on the lower clad layer and inclined with respect to the upper surface of the lower clad layer. A mirror support having a mirror, a mirror formed on an inclined surface along the crystal plane of the mirror support, and a light disposed on the lower cladding layer to guide the light reflected by the mirror or to enter the mirror. A core to be guided and an upper clad disposed on the core are provided.

  The mirror support has an inclined crystal plane, and the mirror is disposed on the inclined surface of the mirror support. Therefore, it is possible to provide a planar waveguide circuit with optical path conversion with high surface flatness and high yield. .

  In the planar waveguide circuit with optical path conversion of the present invention, at least a part of the inclined surface of the mirror may be concave.

  Specifically, the light emitting module of the present invention includes a planar waveguide circuit with an optical path change and a light emitting element that emits light toward a mirror.

  Since the planar waveguide circuit with optical path conversion according to the present invention and the light emitting element are provided, it is possible to provide a light emitting module with small optical loss and easy optical axis adjustment.

  Specifically, the light receiving module of the present invention includes a planar waveguide circuit with an optical path conversion and a light receiving element that receives light from a mirror.

  Since the planar waveguide circuit with optical path conversion according to the present invention and the light receiving element are provided, it is possible to provide a light receiving module with small optical loss and easy optical axis adjustment.

  ADVANTAGE OF THE INVENTION According to this invention, the planar waveguide circuit with an optical path change with low manufacturing cost and its manufacturing method can be provided.

An example of the planar waveguide circuit with an optical path change concerning a first embodiment of the present invention is shown. An example of the state which has laminated | stacked the mirror support body and the etching prevention layer on the lower clad among the mirror support body formation processes which concern on 1st embodiment of this invention is shown. An example of the state which laminated | stacked the resist on the etching prevention layer and removed a part of etching prevention layer among the mirror support body formation processes which concern on 1st embodiment of this invention is shown. An example of the state which formed the mirror support surface by anisotropic etching among the mirror support body formation processes which concern on 1st embodiment of this invention is shown. An example of the state which formed the mirror by lift-off among the mirror formation processes which concern on 1st embodiment of this invention is shown. An example of the state which laminated | stacked the core is shown among the core formation processes which concern on 1st embodiment of this invention. An example of the state which removed the core on a mirror support body after laminating | stacking a core among the core formation processes which concern on 1st embodiment of this invention is shown. An example of the state which laminated | stacked the upper clad among the upper clad formation processes which concern on 1st embodiment of this invention is shown. An example of the planar waveguide circuit with an optical path change concerning a second embodiment of the present invention is shown. An example of the state which laminated | stacked the core is shown among the core formation processes which concern on 2nd embodiment of this invention. An example of the state which removed the core on a mirror support after laminating | stacking a core among the core formation processes which concern on 2nd embodiment of this invention is shown. An example of the state which laminated | stacked the upper clad among the upper clad formation processes which concern on 2nd embodiment of this invention is shown. An example of the state which formed the waveguide hole among the waveguide hole formation processes which concern on 2nd embodiment of this invention is shown. An example of the state which formed the mirror among the mirror formation processes which concern on 2nd embodiment of this invention is shown. An example of the structure of the light emitting module which concerns on 3rd embodiment of this invention is shown. An example of the structure of the light emitting module which concerns on 4th embodiment of this invention is shown. An example of the structure of the light reception module which concerns on 5th embodiment of this invention is shown. An example of the structure of the light reception module which concerns on 6th embodiment of this invention is shown.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to embodiment shown below. These embodiments are merely examples, and the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art. In the present specification and drawings, the same reference numerals denote the same components.

(First embodiment)
FIG. 1 shows a planar waveguide circuit 10 with an optical path change according to the first embodiment of the present invention. The planar waveguide circuit 10 with an optical path conversion according to the present embodiment includes a substrate 11, a lower cladding 12, a mirror support 13, a core 14, an upper cladding 15, and a mirror 16. A lower cladding 12 is disposed on the substrate 11. A mirror support 13, a mirror 16, and a core 14 are disposed on the lower cladding 12. An upper cladding 15 is disposed on the mirror support 13, the mirror 16, and the core 14.

  Reference numeral 111 denotes an example of light that enters the mirror 16 from the upper clad 15 and is reflected by the mirror 16, or light that is guided by the core 14 reflected by the mirror 16. 112 is an example of light that is guided through the core 14 and reflected by the mirror 16, or light that is reflected by the mirror 16 and guided through the core 14. Reference numeral 111 denotes light reflected by the mirror 16 toward the upper side of the substrate 11 or light incident on the mirror 16 from the upper side of the substrate 11. However, the orientation of the mirror arrangement 16 is not limited to the direction in which light is reflected and incident on the upper side of the substrate 11, and the light is reflected and incident on the front side or the rear side with respect to the paper surface of FIG. 1. It may be a direction.

  The lower surface of the mirror support 13 is one surface in contact with the lower cladding 12, and the upper surface of the mirror support 13 is the other surface facing the lower surface of the mirror support 13. The upper surface of the lower cladding 12 is a surface in contact with the mirror support 13 or the core 14, and the lower surface of the lower cladding 12 is the other surface facing the upper surface of the lower cladding 12. The lower surface of the core 14 is a surface in contact with the lower cladding 12, and the upper surface of the core 14 is the other surface in contact with the upper cladding 15. The upper surface of the substrate 11 is a surface in contact with the lower clad 12.

  A method for manufacturing the planar waveguide circuit 10 with an optical path change according to the present embodiment will be described. The manufacturing method of the planar waveguide circuit 10 with an optical path change has a mirror support body formation process, a mirror formation process, a core formation process, and an upper clad formation process in order.

  The mirror support forming step forms an inclined surface for providing the mirror 16 by anisotropically etching at least a part of the mirror support 13 while leaving at least a part of the mirror support 13 on the lower clad 12. It is a process. The mirror forming step is a step of forming the mirror 16 on at least a part of the slope formed in the mirror support forming step. In the core forming step, the core 14 is laminated on the upper surface of the lower clad 12 and the mirror support 13 is not formed, and the waveguide 16 that guides the light reflected by the mirror 16 or the mirror 16 is formed. This is a step of forming a waveguide for guiding incident light. The upper clad forming step is a step of laminating the upper clad 15 on the mirror 16 and the upper surface of the core 14.

First, the mirror support forming process will be described. As shown in FIG. 2, a lower clad 12 is laminated on a flat substrate 11. An example of the substrate 11 is a Si substrate. An example of the lower clad 12 is a buried oxide (BOX) layer in a silicon on insulator (SOI) structure. The BOX layer is an oxide film layer, and SiO ₂ or SiO is used. Next, the mirror support 13 is laminated on the lower cladding 12. An example of the mirror support 13 is a mirror support 12 made of Si. When Si is used for the mirror support 13, the mirror support 13 is stacked so that the (100) plane of the Si crystal becomes the upper surface of the mirror support 13 after stacking.

  Next, as shown in FIG. 2, an etching preventing layer 31 is laminated on the upper surface of the mirror support 13. Examples of the etching prevention layer 31 include an oxide layer such as SiO and a metal layer. Here, the lower clad 12 and the mirror support 13 are stacked on the substrate 11, but an SOI substrate manufactured by bonding having a similar structure may be used. In general, the SOI substrate already has a structure corresponding to the substrate 11, the lower cladding 12, and the mirror support 13. The process from the SOI substrate to the structure of FIG. 3 is only the process of laminating the etching prevention layer 31 on the upper surface of the mirror support 13.

  Next, the step of anisotropically etching at least a part of the mirror support 13 in the mirror support forming step will be described. Specifically, the process from the state shown in FIG. 2 to the state shown in FIG. 3 and the process from the state shown in FIG. 3 to the state shown in FIG. 4 are performed by anisotropically etching at least a part of the mirror support 13. This is a step of forming an inclined surface for providing the surface.

  First, the process from the state of FIG. 2 to the state of FIG. 3 will be described. A resist 32 is applied on the etching prevention layer 31, and the resist 32 other than the upper part of the etching prevention layer 31 that is retained even after etching is removed. An example of the resist 32 is a photoresist. A photoresist is a compound used in photolithography, whose physical properties such as solubility are changed by ultraviolet rays or the like. Photoresist is applied to the material surface to protect the material surface from subsequent processing such as etching. Next, the etching preventing layer 31 that does not have the resist 32 thereon is removed by etching.

  Next, the process from the state of FIG. 3 to the state of FIG. 4 will be described. First, the resist 32 is removed. Next, the mirror support 13 that is not protected by the etching prevention layer 31 is etched from the upper surface of the mirror support 13. The etching performed is anisotropic wet etching. An example of an etchant used for wet etching is potassium hydroxide (KOH). In the etching using KOH, an etching solution containing 40% by mass of KOH is used. The temperature at the time of etching is 80 ° C., for example.

  By the anisotropic wet etching, the mirror support surface 41 which is a slope having a small surface roughness is formed. Furthermore, a voltage may be applied to the mirror support 13 during etching. An example of the voltage applied to the mirror support 13 is 6V. When a voltage is applied to the mirror support 13 during etching, the mirror support surface 41 can be made concave.

  The anisotropic etching will be briefly described. For example, a single crystal of Si has a diamond structure, and Si atoms inside the crystal are each covalently bonded by four bonds. The bonding state of Si atoms on the crystal surface varies depending on the crystal plane appearing on the surface. For example, on the (100) plane of Si, two bonds out of four bonds of Si atoms are cut and connected by two bonds. However, Si atoms are connected by three bonds on the (111) plane of Si, and only one bond is broken. For this reason, the (111) plane is less likely to be etched than the (100) plane, and the etching rate is slow. As a result, when the Si single crystal is wet-etched from the (100) plane of Si, a (111) plane that is difficult to etch appears on the surface. The surface remaining after the etching is a smooth surface along the crystal plane.

  When the mirror support 13 is a single crystal of Si, anisotropic wet etching is performed from the upper surface of the mirror support 13, so that the mirror support surface 41 is a Si (111) surface. That is, the crystal plane of the mirror support 13 is exposed to be inclined with respect to the lower cladding 12 by etching. However, the orientation of the Si (111) plane is determined by the orientation of the crystal axis of the mirror support 13 which is a Si single crystal. Therefore, by changing the direction of the crystal axis when the mirror support 13 is stacked, the direction of the (111) plane of Si to be exposed can be changed. That is, the direction in which the light incident on the mirror 16 is reflected can be selected by changing the orientation of the exposed Si (111) plane.

  When the mirror support 13 having the Si (100) surface as a surface is etched with KOH from the upper surface, that is, from the upper side in FIG. 3, the angle α of the mirror support surface 41 shown in FIG. 4 becomes about 55 degrees. In the etching for applying a voltage to the mirror support 13, the mirror support surface 41 becomes concave, so that the mirror 16 also has a light collecting effect. Although etching using KOH has been described here, other examples of the etchant include tetramethylammonium hydroxide (TMAH) and a mixed solution of nitric acid, hydrofluoric acid, and acetic acid.

  Next, the mirror forming process will be described. The mirror formation step is a step from the state of FIG. 4 to the state of FIG. 5, and the mirror 16 is formed on at least a part of the mirror support surface 41 that is an inclined surface provided on the mirror support 13. For example, the mirror 16 is formed by laminating metal reflective films by lift-off. Lift-off is a technique in which when a metal is deposited on a pattern made of a photoresist and the photoresist is removed later, the metal pattern remains only in a portion where there is no photoresist. Metal is deposited only on the portion where the optical path conversion mirror 16 is formed by lift-off. Gold and aluminum are mentioned as an example of the metal used as a reflecting film. The mirror 16 changes the optical path by reflecting light.

  Next, the step of laminating the core 14 on the upper surface of the lower clad 12 in the core forming step will be described. Specifically, the process from the state of FIG. 5 to the state of FIG. 6 is a process of laminating the core 14 on the upper surface of the lower cladding 12. First, the etching prevention layer 31 is removed. Next, the core 14 is laminated on the upper surface of the mirror support 13, the mirror 16, and the lower cladding 12.

  Next, a step of forming a waveguide for guiding light reflected by the mirror 16 or a waveguide for guiding light incident on the mirror 16 in the core forming step will be described. Specifically, the process from the state of FIG. 6 to the state of FIG. 7 is a process of forming a waveguide for guiding the light reflected by the mirror 16 or a waveguide for guiding the light incident on the mirror 16. is there.

  In FIG. 6, a resist 71 is applied to a part of the upper surface of the core 14. The part of the upper surface of the core 14 to which the resist 71 is applied is the upper surface of the core 14 that faces the lower surface of the core 14 in contact with the lower cladding 12 or the mirror 16. Next, the core 14 on which the resist 71 is not applied is etched, and the core 14 on the mirror support 13 is removed. Although not shown in FIG. 7, the core 14 on the mirror 16 may be flattened like the core 14 shown in FIG. A waveguide is completed with the end of the core formation process.

  Next, an upper clad formation process is demonstrated. The upper clad forming step is a step of laminating the upper clad 15 on the mirror 16 and the upper surface of the core 14, and corresponds to the step from the state of FIG. 7 to the state of FIG. Specifically, first, the resist 71 is removed. Next, the upper clad 15 is laminated on the upper surface of the mirror support 13, the optical path conversion mirror 16, and the core 14. Although not shown in FIG. 8, like the core 14 and the upper cladding 15 shown in FIG. 1, the protrusions of the core 14 on the optical path conversion mirror 16 and the upper cladding 15 on the optical path conversion mirror 16 are flattened. It may be.

  In the first embodiment, for example, the thickness of the lower cladding 12 is 15 μm or more, the thickness of the core 14 is 5 μm, and the thickness of the upper cladding 15 is 15 μm or more. The thicknesses of the lower cladding 12 and the upper cladding 15 are determined by the refractive index difference δ from the core 14. Therefore, the thickness of the lower clad 12 and the upper clad 15 can be made thinner than 15 μm by increasing the refractive index of the core 14.

(Second embodiment)
FIG. 9 shows a planar waveguide circuit 20 with an optical path change according to the second embodiment of the present invention. The planar waveguide circuit 20 with an optical path conversion according to the present embodiment includes a substrate 11, a lower cladding 12, a mirror support 13, a core 14, an upper cladding 15, a mirror 16, and a waveguide hole 21. . In the planar waveguide circuit with optical path conversion 20 according to the present embodiment, the planar waveguide circuit with optical path conversion according to the first embodiment further includes a waveguide hole.

  A method for manufacturing the planar waveguide circuit 20 with an optical path change according to the present embodiment will be described. The manufacturing method of the planar waveguide circuit 20 with an optical path conversion includes a mirror support forming step, a core forming step, an upper clad forming step, a waveguide hole forming step, and a mirror forming step in this order. In the first embodiment, the core formation process is performed after the mirror formation process, but in this embodiment, the mirror formation process is performed after the upper cladding formation process. In connection with this, in this embodiment, it has a waveguide hole formation process between an upper clad formation process and a mirror formation process. The waveguide hole forming step is a step of removing the core 14 and the upper clad 15 on the mirror support surface 41 that is an inclined surface.

  First, the mirror support forming process will be described. The mirror support formation process according to the present embodiment is the same as the mirror support formation process according to the first embodiment.

  Next, the core forming process will be described. In the core forming process according to the present embodiment, the core 14 is laminated on the upper surface of the mirror support 13 and the upper surface of the lower cladding 12 to form the core 14 as shown in FIG. After the core 14 is laminated, a resist 71 is applied and etching is performed. The core 14 as shown in FIG. 11 is formed as in the first embodiment.

  Next, an upper clad formation process is demonstrated. The upper clad forming process according to the present embodiment is the same as the upper clad forming process according to the first embodiment. The upper clad 15 as shown in FIG. 12 is formed by the upper clad forming step.

  Next, the waveguide hole forming step will be described. In the waveguide hole forming step, the core 14 and the upper clad 14 on the mirror support surface 41 which is a slope are removed. Specifically, a resist 72 is applied to a portion of the upper surface of the upper clad 15 formed in the upper clad formation step as shown in FIG. A metal film may be used instead of the resist 72. Thereafter, the core 14 and the upper clad 15 on the mirror support surface 41 which is an inclined surface are removed by dry etching, and the waveguide hole 21 shown in FIG. 13 is formed. Since dry etching is used, the core 14 and the upper clad 15 are removed by etching, but the mirror support 13 is not etched because the material is different from that of the core 14 and the upper clad 15.

  Next, the mirror forming process will be described. In the mirror forming step according to the present embodiment, after forming the waveguide hole 21 as shown in FIG. 13, the mirror 16 is formed on at least a part of the mirror support surface 41 that is an inclined surface. The mirror 16 is formed, for example, by laminating a metal reflection film. The metal reflective film is laminated by vapor deposition, for example. Thereafter, the resist 72 is removed, and the planar waveguide circuit 20 with optical path conversion shown in FIG. 14 is formed. Here, the resist 72 is removed after the mirror 16 is formed, but the mirror 16 may be formed after the resist 72 is removed.

(Third embodiment)
FIG. 15 shows an example of a light emitting module according to the third embodiment of the present invention. The light emitting module according to this embodiment includes a planar waveguide circuit 10 with an optical path change, a light emitting element 91, and an optical element support substrate 93. The optical element support substrate 93 is a substrate that supports the light emitting element 91. Reference numeral 92 denotes a reflecting surface for guiding the output light of the light emitting element 91 to the optical path 911 when the light emitting element 91 is an end face light emitting element such as an LD. When the light emitting element 91 is a surface light emitting element and the light emitting surface faces the upper cladding 15, the reflecting surface 92 is not necessary. Reference numeral 911 denotes an optical path until the light output from the light emitting element 91 is reflected by the mirror 16, and 912 denotes an optical path after the light output from the light emitting element 91 is reflected by the mirror 16.

  The light output from the light emitting element 91 passes through the upper clad 15, is input to the core 14, is reflected by the mirror 16, and is guided inside the core 14. When the light emitting element 91 has the reflecting surface 92, the reflecting surface 92 is inserted into the optical path 911 between the light emitting element 91 and the upper clad 15.

(Fourth embodiment)
FIG. 16 shows an example of a light emitting module according to the fourth embodiment of the present invention. The light emitting module according to this embodiment includes a planar waveguide circuit 20 with an optical path conversion, a light emitting element 91, and an optical element support substrate 93. The light emitting module according to the third embodiment includes the planar waveguide circuit 10 with optical path conversion, but the light emitting module according to the present embodiment includes the planar waveguide circuit 20 with optical path conversion.

(Fifth embodiment)
FIG. 17 shows an example of a light receiving module according to the fifth embodiment of the present invention. The light receiving module according to this embodiment includes a planar waveguide circuit 10 with an optical path change and a light receiving element 1001. Although the third embodiment includes a light emitting element 91, the present embodiment includes a light receiving element 1001. Here, the optical paths of the light received by the light receiving element are 1011 and 1012. 1011 is an optical path after the light received by the light receiving element 1001 is reflected by the mirror 16, and 1012 is an optical path before the light received by the light receiving element 1001 is reflected by the mirror 16. The light guided through the core 14 is reflected by the mirror 16, passes through the upper cladding 15, and is input to the light receiving element 1001.

(Sixth embodiment)
FIG. 18 shows an example of a light receiving module according to the sixth embodiment of the present invention. The light receiving module according to the present embodiment includes a planar waveguide circuit 20 with optical path conversion and a light receiving element 1001.
The light receiving module according to the fifth embodiment includes the planar waveguide circuit 10 with optical path conversion, but the light receiving module according to the present embodiment includes the planar waveguide circuit 20 with optical path conversion.

  The planar waveguide circuit with optical path conversion and the manufacturing method thereof according to the present invention can be applied to the communication industry.

10: Planar waveguide circuit with optical path conversion 11: Substrate 12: Lower clad 13: Mirror support 14: Core 15: Upper clad 16: Mirror 111: Optical path 112: Optical path 20: Planar waveguide circuit with optical path conversion 21: Waveguide Hole 31: Etching prevention layer 32: Resist 41: Mirror support surface 71: Resist 72: Resist 91: Light emitting element 92: Reflecting surface 93: Optical element support substrate 911: Optical path 912: Optical path 1001: Optical element 1011: Optical path 1012: Optical path

Claims (8)

A method of manufacturing a planar waveguide circuit having an optical path conversion function in which a mirror is provided in a planar waveguide circuit including a core, an upper cladding, and a lower cladding,
Mirror support forming step of forming an inclined surface for providing the mirror by anisotropically etching at least a part of the mirror support, leaving at least a part of the mirror support disposed on the lower cladding When,
A mirror forming step of forming the mirror on at least a part of the slope;
To the waveguide, which is on the lower clad and on which the mirror support is not formed and on the inclined surface, the core is laminated, and guides the light reflected by the mirror, or to the mirror A core forming step of forming a waveguide for guiding incident light;
An upper clad forming step of laminating the upper clad on the mirror and the core;
A method of manufacturing a planar waveguide circuit with an optical path change. A method of manufacturing a planar waveguide circuit having an optical path conversion function in which a mirror is provided in a planar waveguide circuit including a core, an upper cladding, and a lower cladding,
Mirror support forming step of forming an inclined surface for providing the mirror by anisotropically etching at least a part of the mirror support, leaving at least a part of the mirror support disposed on the lower cladding When,
To the waveguide, which is on the lower clad and on which the mirror support is not formed and on the inclined surface, the core is laminated, and guides the light reflected by the mirror, or to the mirror A core forming step of forming a waveguide for guiding incident light;
An upper clad forming step of laminating the upper clad on the slope and the core;
A waveguide hole forming step of removing the core and the upper clad on the inclined surface;
A mirror forming step of forming the mirror on at least a part of the slope;
A method of manufacturing a planar waveguide circuit with an optical path change. In the mirror support forming step, the inclined surface is made concave by performing anisotropic etching of the mirror support while applying a voltage to the mirror support.
The manufacturing method of the planar waveguide circuit with an optical path change of Claim 1 or 2. In the mirror support formation step, the mirror support is laminated so that the crystal plane of the mirror support is inclined with respect to the lower cladding,
Etching so that the slope is exposed,
The manufacturing method of the planar waveguide circuit with an optical path change in any one of Claim 1 to 3. A lower cladding layer disposed on the substrate;
A mirror support disposed on the lower cladding layer and having a crystal plane inclined with respect to the upper surface of the lower cladding layer;
A mirror formed on a slope along the crystal plane of the mirror support;
A core that is disposed on the lower cladding layer and guides the light reflected by the mirror, or guides the light incident on the mirror;
An upper cladding disposed over the core;
A planar waveguide circuit with optical path conversion. The planar waveguide circuit with an optical path conversion according to claim 5, wherein at least a part of the inclined surface of the mirror is a concave surface. A planar waveguide circuit with an optical path change according to claim 5 or 6,
A light emitting element that emits light toward the mirror;
A light emitting module comprising. A planar waveguide circuit with an optical path change according to claim 5 or 6,
A light receiving element for receiving light from the mirror;
A light receiving module.

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