JP2004170668A - Optical transmitting/receiving module, its manufacturing method and optical communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical transmitting/receiving module having high optical coupling efficiency and low manufacturing cost and enabling two-way information transfer. <P>SOLUTION: The optical transmitting/receiving module 10 comprises: a single-core multimode polymer optical waveguide 14 having a Y-branch 12; a planar light emitting semiconductor laser element 16 as a light source of the optical signal transmission apparatus disposed at one end of the Y-branch of the optical waveguide; and a photodiode 18 as a receiving element of the optical signal receiving apparatus disposed at the other end. The end faces of the first and second optical waveguide branches 14b, 14c are 45° inclined faces. The optical signal light exiting upward in the direction orthogonal to the element substrate from the planar light emitting semiconductor laser element enters the inclined face of the first optical waveguide branch with high optical coupling efficiency; the light is reflected to propagate through the core layer of the optical waveguide by total reflection; and the light passes the Y-branch and exits outward from the optical waveguide body 14a. The signal light is received by the photodiode by the similar principle. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical transmission / reception module, an optical communication system, and an optical communication system including an optical signal transmission device and an optical signal reception device and capable of performing simultaneous optical communication at the same time. The present invention relates to an optical transmission / reception module, an optical communication system, and a method for manufacturing the same, which are capable of performing simultaneous bidirectional optical communication and have an optimum configuration for optical interconnection.
[0002]
[Prior art]
2. Description of the Related Art In accordance with technical progress of semiconductor integrated circuits, the degree of integration of the semiconductor integrated circuits has been increased, and the operation speed of the semiconductor integrated circuits has been increased. For example, the performance of microprocessors is increasing, and the capacity of memory chips is increasing rapidly.
As the performance of integrated circuits has been improved, the speed of signals in the circuits and the density of signal wiring have been increased.
[0003]
2. Description of the Related Art Conventionally, information transmission over a relatively short distance, such as between devices, between boards in a device, or between chips in a board, is mainly performed by transmission of electric signals via electric wiring.
At present, electric wiring, which is widely used, has a limitation in high-frequency response when the system is speeded up. Specifically, high-frequency operation is limited by competition between buses, multiple reflection, skin effect, high-frequency loss due to dielectric loss, S / N due to low-amplitude operation, and the like, so that reliability is reduced. In addition, high-speed electric signals and high-density electric wiring cause EMI (Electromagnetic Interference) noise and crosstalk between channels.
In other words, as long as information is transmitted by transmitting electric signals through electric wiring, not only high speed and high density are difficult, but also the occurrence of crosstalk and signal delay due to the time constant of the wiring pose problems. Become.
[0004]
Therefore, as information transmission means between devices, between boards in a device, or between chips in a board, optical interconnection using optical signal wiring is attracting attention instead of information transmission using electric signals. Moreover, next-generation optical interconnections require large-capacity, high-speed communication.
Conventionally, inorganic materials such as silica glass and multi-component glass have been widely used as base materials for optical components or optical fibers because of their low light propagation loss and wide transmission band. Inorganic optical waveguides have high performance but are expensive, and it is difficult to spread optical signal wiring.
[0005]
Therefore, in place of the quartz optical waveguide, in recent years, a polymer (polymer) optical waveguide that has better workability than inorganic materials and is easy to manufacture at low cost has attracted attention and has been developed.
For example, as an optical fiber using a polymer material for an optical waveguide, a highly transparent polymer material such as polymethyl methacrylate (PMMA) or polystyrene is used as a core, and a plastic having a lower refractive index than the core material is used as a cladding material. A planar polymer optical waveguide having a core / cladding structure has been manufactured. In addition, a planar polymer optical waveguide using polyimide or polysiloxane, which is a polymer having excellent heat resistance and high transparency, has also been manufactured.
[0006]
Here, as an example of a planar polymer optical waveguide, a method of manufacturing a planar polymer optical waveguide disclosed in Japanese Patent Application Laid-Open No. 8-304650 will be described with reference to FIG. 9 (a) to 9 (c) are cross-sectional views of respective steps when a flat-plate type polymer optical waveguide is manufactured by the method disclosed in the above-mentioned publication.
Prior to the production of a polymer optical waveguide, a copper film 74 having a thickness of about 100 nm is formed on a silicon substrate 72 by a sputtering method, and this is used as a substrate 76. An embedded polymer optical waveguide is produced on the substrate 76.
[0007]
First, as shown in FIG. 9A, a lower cladding layer 78 made of a solution-type transparent high-molecular organic compound is formed on a substrate 76 by spin coating. Subsequently, a core layer 80 made of a polymer organic compound having a higher refractive index than the lower cladding layer 78 is formed on the lower cladding layer 78 by a spin coating method.
Next, a resist mask (not shown) having a stripe pattern is formed on the core layer 80, and the core layer 80 is etched by a reactive ion etching method using the resist mask as an etching mask, as shown in FIG. 9B. Next, the core layer 82 is processed into a belt-like core layer 82.
Further, as shown in FIG. 9C, an upper clad layer 84 made of the same high molecular weight organic compound as the lower clad layer 78 is formed on the lower clad layer 78 and the strip-shaped core layer 82 by spin coating. A polymer optical waveguide structure 86 composed of a lower cladding layer 78, a strip-shaped core layer 82, and an upper cladding layer 84 is formed on 76.
Next, the polymer optical waveguide structure 86 is peeled from the substrate 76 to form a polymer optical waveguide film.
[0008]
As an example of an optical interconnection device, an optical integrated circuit in which a semiconductor laser element, a photodiode, and a polymer optical waveguide are integrated is disclosed in JP-A-2000-235127, JP-A-2001-42150, and JP-A-2002-6161. (Hereinafter referred to as a first conventional example).
As an example of a module capable of bidirectional optical communication, a PLC (Planar Lightwave Circuit) in which a semiconductor laser element, a photodiode, and the like are integrated on one substrate is disclosed in Japanese Patent Application Laid-Open No. 2002-169043 (hereinafter, referred to as a second example). Conventional example).
[0009]
[Patent Document 1]
JP-A-2002-169043 (FIG. 1)
[0010]
[Problems to be solved by the invention]
However, in each of the first conventional examples, the semiconductor laser element and the light receiving element are integrated on the same substrate and are modularized through a polymer optical waveguide. There is a problem that the data is transmitted only in one direction toward.
[0011]
In the second conventional example, a single mode optical waveguide is used as an optical waveguide, and a Fabry-Perot semiconductor laser element or a negative feedback distributed semiconductor An edge-emitting semiconductor laser device such as a laser device is used.
In the single mode optical waveguide, since only the fundamental mode is established, it is optimal for a long-distance optical communication system. Therefore, the second conventional example is not the short-range information transmission which is the subject of the present invention, but rather, It is believed that it was developed for long-haul optical communication systems.
[0012]
By the way, the single mode optical waveguide has the following two problems.
First, it is difficult to couple the laser light and the single mode optical waveguide, and the optical coupling efficiency is poor. Second, since a thin optical waveguide of about several μm is required, high-precision processing technology is required, and the manufacturing cost is increased.
[0013]
By the way, in applications of short-distance transmission used for optical interconnection, an optical communication system that has high optical coupling efficiency, low manufacturing cost, and is capable of bidirectional information transmission is required.
The present invention has been made in view of the above-described demands, and has as its object to provide an optical communication system which has high optical coupling efficiency, low manufacturing cost, and capable of bidirectional information transmission, and an optical communication system used for the optical communication system. It is to provide a transmitting / receiving module.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present inventor has
(1) using a multimode single-core polymer (polymer) optical waveguide to reduce the cost of the optical waveguide;
(2) In order to enable information transmission of bidirectional full-duplex communication with a single-core optical waveguide, a Y-branch is provided in the optical waveguide, and an optical signal transmission device is provided on each of the two branched optical waveguides. And configuring an optical transmission and reception module provided with an optical signal receiving device, and
(3) In order to increase the optical coupling efficiency, a surface emitting semiconductor laser device is used as a light source of an optical signal transmission device, and the optical waveguide is optically coupled with the end surface of the optical waveguide being inclined. With the idea (the same applies to the optical coupling between the photodiode and the optical waveguide), it was confirmed through experiments that the idea was effective, and the present invention was reached.
[0015]
In order to achieve the above object, an optical transceiver module according to the present invention includes a single-core multi-mode optical waveguide connected to an external optical waveguide, and a first optical waveguide branch and a second optical waveguide branch. A Y-branch that branches into a Y-shape, an optical signal transmitting device provided at an end of the first optical waveguide branch, and an optical signal receiving device provided at an end of the second optical waveguide branch. With
The first optical waveguide branch and the second optical waveguide branch each have an inclined end face obliquely intersecting the extending direction of the core layer of the optical waveguide as an end face of each end,
The optical signal transmission device has, as a light source, a surface emitting semiconductor laser element that uses the inclined end surface of the first optical waveguide branch as a reflection surface, reflects the emitted optical signal light on the inclined end surface, and makes the light signal light enter the optical waveguide,
The optical signal receiving device is characterized in that the inclined end face of the second optical waveguide branch is used as a reflecting surface, and a light receiving element is provided for receiving the optical signal light guided from the optical waveguide by reflecting the optical signal light at the inclined end face.
[0016]
In the present invention, a surface emitting semiconductor laser element and a light receiving element are provided at each end of the first and second optical waveguide branches following the Y-branch of the single-core multimode optical waveguide, and the inclined end faces of each end are provided. As the reflection surface, the optical signal light from the surface emitting semiconductor laser device is incident on the optical waveguide, and the optical signal light is incident on the light receiving device from the optical waveguide, so that the surface emitting semiconductor laser device and the optical waveguide or the optical waveguide and the optical waveguide are received. An optical transceiver module having high optical coupling efficiency with the element and capable of bidirectional optical communication has been realized.
Here, the multi-mode optical waveguide has a core layer having a thickness of, for example, 20 μm to 50 μm, and more preferably 50 μm or more, as compared with a single mode optical waveguide having a thickness of several μm. A multimode optical waveguide is an optical waveguide through which light of a higher mode as well as the fundamental mode propagates, and is mainly used for optical communication over a short distance. A single mode optical waveguide is an optical waveguide that propagates light only in a fundamental mode, and is mainly used for long-distance optical communication.
[0017]
In a preferred embodiment of the present invention, the optical waveguide is a polymer optical waveguide. Thereby, the optical transceiver module can be economically manufactured.
Further, the upper surface of the lower clad layer constituting the optical waveguide is flush with the emission surface of the surface emitting semiconductor laser device and the light receiving surface of the light receiving device. Thereby, the optical coupling efficiency between the surface emitting semiconductor laser device and the light receiving device and the optical waveguide can be further increased.
Further, the inclined surface forms an angle of 45 ° with the extending direction of the core layer. With this, the surface emitting semiconductor laser element and the light receiving element can be arranged or built in a direction orthogonal to the substrate, so that the manufacturing becomes easy.
[0018]
In the present invention, the substrate of the optical transceiver module is not limited, and for example, a polyimide substrate, a glass substrate, a quartz substrate, a Si substrate, a GaAs substrate, an InP substrate, an SOI (Silicon on Insulator) substrate, or the like can be used. Also, the substrate of the optical transceiver module can be a common substrate with the component substrate of the surface emitting semiconductor laser device or the component substrate of the light receiving element.
[0019]
In the method for manufacturing an optical transceiver module according to the present invention, a single-core multi-mode optical waveguide connected to an external optical waveguide, and the optical waveguide is formed into a Y-shaped first optical waveguide branch and a second optical waveguide branch. Optical transmission / reception module, comprising: a Y-branch unit that branches into a first optical waveguide branch; an optical signal transmitting device provided at an end of a first optical waveguide branch; and an optical signal receiving device provided at an end of a second optical waveguide branch. The method for producing
At a predetermined position on the substrate, a surface emitting semiconductor laser element as a light source of the optical signal transmitting device, and a photodiode as a light receiving element of the optical signal receiving device, or a step of creating,
Forming a lower cladding layer of the optical waveguide such that the light emitting surface of the surface emitting semiconductor laser device and the light receiving surface of the light receiving device are flush with the upper surface of the lower cladding layer;
A core forming layer is formed on the lower cladding layer, and then a mask having a predetermined optical waveguide planar shape is placed on the core forming layer, and ultraviolet light is irradiated from above the mask, and the refractive index of an area exposed from the mask is determined by the core. A region other than the exposed region is made smaller than the formation layer to form an intermediate cladding layer, and the region other than the exposed region is formed on the optical waveguide, the Y branch portion, the first optical waveguide branch having an end on the surface emitting semiconductor laser element, and the end on the photodiode. Forming a core layer of a second optical waveguide branch having:
Forming an upper cladding layer on the core layer and the intermediate cladding layer to form an optical waveguide, a Y-branch, a first optical waveguide branch, and a second optical waveguide branch;
An inclined end face is provided at an end of the first optical waveguide branch so that an optical signal light is made to enter the core layer of the first optical waveguide branch from the surface emitting semiconductor laser element with the inclined end face as a reflection surface, and the inclined end face is provided. Providing an inclined end surface at the end of the second optical waveguide branch so that the optical signal light is incident on the photodiode from the second optical waveguide branch as a reflection surface;
It is characterized by having.
[0020]
In a preferred embodiment of the present invention, a surface emitting semiconductor laser device and a photodiode are arranged or formed at a predetermined position on a substrate in a direction orthogonal to the substrate, and a core layer of the first and second optical waveguide branches is formed. An inclined end face is formed at an angle of 45 ° in the extending direction.
Thereby, it becomes easier to manufacture a surface emitting semiconductor laser device and an optical transceiver module having high optical coupling efficiency between the photodiode and the optical waveguide.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described specifically and in detail with reference to the accompanying drawings.
Embodiment of optical transmission / reception module
This embodiment is an example of an embodiment of the optical transceiver module according to the first invention. FIG. 1 is a top view showing a configuration of a main part of the optical transceiver module of the present embodiment, FIG. 2A is a cross-sectional view of the optical waveguide taken along line II in FIG. 1, and FIG. 3 is a cross-sectional view of the optical waveguide taken along line II-II, FIG. 3 is a graph illustrating the shape of the Y-branch, FIG. 4 is a cross-sectional view of a main part of the optical signal transmission device taken along line III-III in FIG. 5 is a cross-sectional view of a main part of the optical signal receiving device taken along line IV-IV in FIG.
As shown in FIG. 1, the optical transceiver module 10 according to the present embodiment includes an optical waveguide 14 having a Y-branch 12 and one end of the Y-branch 12 of the optical waveguide 14 as a light source of an optical signal transmission device. The semiconductor laser device includes a surface-emitting semiconductor laser element 16 provided and a photodiode 18 provided at the other end as a receiving element of the optical signal receiving device.
[0022]
The optical waveguide 14 is a single-core multimode polymer optical waveguide. As shown in FIG. 2, a lower clad layer 22 and a core layer having a refractive index of 0.4 to 1.5% are formed on a module substrate 20. 24 and an upper clad layer 26, and has a cross-sectional shape in which the core layer 24 is sandwiched between the lower clad layer 22 and the upper clad layer 26 whose refractive index is smaller than the core layer 24.
[0023]
The core layer 24 is formed of a high-molecular organic compound having a characteristic of lowering the refractive index upon irradiation with ultraviolet light. Although both sides of the core layer 24 are formed of the same high-molecular organic compound as the core layer 24, It is sandwiched by an intermediate cladding layer 25 whose refractive index is lowered by the irradiation of the core layer 24.
The lower cladding layer 22 and the upper cladding layer of the optical waveguide 14 are formed of a polymer resin whose refractive index changes by irradiation with ultraviolet rays, for example, a fluorinated polyimide (manufactured by NTT-AT).
Further, the core layer 22 and the intermediate cladding layer 25 are formed of a polymer resin having a higher refractive index than fluorinated polyimide, and the refractive index of which is also changed by ultraviolet irradiation, for example, Gracia (Nippon Paint).
[0024]
Further, the core layer and the cladding layer can be constituted by the same high molecular weight organic compound. For example, using two types of fluorinated polyimides having different refractive indices, a high refractive index fluorinated polyimide is used for the core layer 24, and a low refractive index fluorinated polyimide is used for the lower cladding layer 22, the intermediate cladding layer 25, and the upper cladding layer 26. Used.
Similarly, use the same high molecular weight organic compound such as Gracia (Nippon Paint) and oxetane resin (Sony Chemical Co.) with different refractive indices. The material is used for the core layer.
[0025]
In this embodiment, the module substrate 20 is a common substrate with the substrate of the surface emitting semiconductor laser element 16 and the photodiode 18.
The module substrate 20 does not necessarily need to be a common substrate, and may be configured as a single module substrate. At that time, for example, a polyimide substrate, a glass substrate, a quartz substrate, a Si substrate, a GaAs substrate, an InP substrate, and an SOI (Silicon on Insulator) substrate can be used.
[0026]
As shown in FIG. 1, the Y-branch unit 12 includes a single-core optical waveguide 14 and two single-core multimode optical waveguide branches, that is, a first optical waveguide branch 14b and a second optical-mode branch 14b. It has a Y-shaped optical waveguide structure that branches into the optical waveguide branch 14c.
The optical waveguide 14 enters from the outside and is connected to the Y branch portion 12 and is branched by the Y branch portion 12. Each of the optical waveguides 14 has the same configuration as the optical waveguide body 14 a and is substantially obliquely directed to the optical waveguide body 14 a. From the first optical waveguide branch 14b and the second optical waveguide branch 14c extending parallel to the optical waveguide body 14a and connected to the surface emitting semiconductor laser element 16 and the photodiode 18. It is configured.
[0027]
The length, width, thickness, shape of the Y-branch portion 12, and the like of the optical waveguide 14 are set by computer simulation so as to reduce the transmission loss. For example, when the interval between the first and second optical waveguide branches 14b and 14c is set to 0.25 mm so that the propagation loss is reduced, as shown in FIG. The length d of the portion is set to 2.5 mm or more.
[0028]
As shown in FIG. 4, the surface emitting semiconductor laser element 16 includes an n-type semiconductor substrate 28 common to the module substrate 20, an n-type DBR mirror 30, and a λ resonator formed sequentially on the n-type semiconductor substrate 28. 32, and a p-type DBR mirror 34, which emits light from the upper p-type DBR mirror 34 in an upward direction orthogonal to the n-type semiconductor substrate 28, and has a conventionally known cylindrical surface-emitting semiconductor laser device. It is. The emission surface is the upper surface of the p-type DBR mirror 34.
The optical signal transmitting device, in addition to the surface emitting semiconductor laser device 16, not shown, similarly to a conventional optical signal transmitting device, drives and controls the surface emitting semiconductor laser device 16 on a semiconductor substrate 28, for example. It is provided with the surface emitting semiconductor laser element 16.
[0029]
As shown in FIG. 4, the end 36 of the first optical waveguide branch 14 b has an end face 36 a at 45 ° (θ) with respect to the extending direction of the lower cladding layer 22, the core layer 24, and the upper cladding layer 26. And is formed as an inclined surface. The surface emitting semiconductor laser element 16 is provided in a direction orthogonal to the module substrate 20, and is incident on the first optical waveguide branch 14 b so that the emitted light is incident on the inclined surface of the core layer 24 at a direction of 45 °. Optically coupled.
With the above configuration, the laser light emitted from the surface emitting semiconductor laser element 16 is incident on the inclined surface of the core layer 24 as an optical signal light with high optical coupling efficiency, is reflected there, and is reflected inside the core layer 24 by total internal reflection. The light propagates through the Y-branch 12 and exits through the optical waveguide body 14a.
With the above-described optical coupling structure, the surface emitting semiconductor laser element 16 and the first optical waveguide branch 14b can be coupled with high optical coupling efficiency.
[0030]
As shown in FIG. 5, the photodiode 18 includes an n-type semiconductor substrate 38 common to the module substrate 20, and an n-type semiconductor layer 40 and an i-type semiconductor layer sequentially formed on the n-type semiconductor substrate 38. A photodiode having a known configuration, which has a cylindrical pin structure including the semiconductor device 42 and a p-type semiconductor layer 44, wherein the light receiving surface is the upper surface of the p-type semiconductor layer 44.
The optical signal receiver includes, in addition to the photodiode 18, a signal converter and the like (not shown) attached to the photodiode 18, for example, on a semiconductor substrate 38, like the conventional optical signal receiver.
[0031]
As shown in FIG. 5, the end 46 of the second optical waveguide branch 14c has an end surface 46a of 45 ° (θ) with respect to the extending direction of the lower cladding layer 22, the core layer 24, and the upper cladding layer 26. And is formed as an inclined surface. The photodiode 18 is provided in a direction perpendicular to the module substrate 20, and the light is reflected on the first optical waveguide branch 14b such that the optical signal light reflected on the inclined surface of the core layer 24 is orthogonally incident on the light receiving surface. Are combined.
With the above configuration, the optical signal light that has entered the optical transceiver module 10 from the outside passes through the Y-branch portion 12 from the optical waveguide main body 14a to the inclined surface of the core layer 24 at the end 46 of the second optical waveguide branch 14c. The light is incident on the light receiving surface of the photodiode 18 after being reflected.
With the above-described optical coupling structure, the second optical waveguide branch 14c and the photodiode 18 can be coupled with high optical coupling efficiency.
[0032]
With the above configuration, the optical transceiver module 10 according to the present embodiment has high optical coupling efficiency between the surface emitting semiconductor laser element 16 and the optical waveguide 14 or between the optical waveguide 14 and the photodiode 18 and has a single-core multimode height. By using the molecular optical waveguide 14, an optical transceiver module capable of performing simultaneous bidirectional optical communication is realized.
[0033]
Embodiment of manufacturing method of optical transceiver module
This embodiment is an example of an embodiment in which the method for manufacturing an optical transceiver module according to the present invention is applied to the fabrication of the optical transceiver module 10 described above, and FIGS. 6A to 6C and FIG. FIGS. 5E and 5E are cross-sectional views of respective steps corresponding to line VV in FIG. 1 when the optical transceiver module is manufactured by the method of the embodiment.
First, as shown in FIG. 6A, the surface emitting semiconductor laser element 16 and the photodiode 18 are located at the positions shown in FIG. 1, and the emitting surface of the surface emitting semiconductor laser element 16 and the light receiving surface of the photodiode 18 are the same. It is arranged on the module substrate 20 so as to be on a plane. Further, the surface emitting semiconductor laser element 16 and the photodiode 18 may be formed at the positions shown in FIG.
[0034]
Next, as shown in FIG. 6B, a polymer resin, for example, a fluorinated polyimide resin is applied to the substrate on the module substrate 20 to form a lower clad layer forming layer, followed by baking. The upper surface is flattened so as to have the same height as the height of the emission surface of the surface emitting semiconductor laser element 16 to form the lower cladding layer 22 constituting the optical waveguide 14.
As a result, the surface emitting semiconductor laser element 16 can be buried with the lower cladding layer 22 by exposing the light emitting surface, and the photodiode 18 can be buried by exposing the light receiving surface.
Next, as shown in FIG. 6C, a polymer resin, for example, gracia is applied on the lower cladding layer 22 to form a gracia layer, and a core forming layer 48 is formed.
[0035]
Next, as shown in FIG. 7D, a mask 50 having the planar shape of the optical waveguide main body 14a, the Y branch portion 12, and the first and second optical waveguide branches 14b and 14c is mounted on the core forming layer 48. Irradiate with ultraviolet light.
Since the refractive index of gracia is increased by ultraviolet rays, the refractive index of the region exposed from the mask 50 is made smaller than that of the core forming layer 48 to form the intermediate cladding layer 25, and the region other than the exposed region is the optical waveguide main body 14a and the Y branch portion. 12, the core layer 24 of the first optical waveguide branch 14b and the second optical waveguide branch 14c.
[0036]
Next, the mask 50 is removed, and as shown in FIG. 7E, a polymer resin, for example, a fluorinated polyimide resin is applied to the substrate on the core layer 24 and the intermediate cladding layer 25 to form an upper cladding layer forming layer. A film is formed and subsequently baked to form an upper cladding layer 26.
[0037]
Next, as shown in FIGS. 4 and 5, the end portion 36 of the first optical waveguide branch 14b optically coupled to the surface emitting semiconductor laser device 16 and the second optical waveguide branch 14c optically coupled to the photodiode 18 Is polished to form a 45 ° inclined surface to be a reflecting surface.
In the formation of the 45 ° inclined surface, the lower clad layer 22, the core layer 24, the intermediate clad layer 25, and the upper clad layer 26 are subjected to grinding using, for example, a diamond blade to form 45 ° inclined end surfaces 36a and 46a. be able to.
[0038]
According to the method of the present embodiment, the surface emitting semiconductor laser element 16 and the photodiode 18 are arranged or formed on the module substrate 20, then the optical waveguide 14 is formed, and the end face processing is performed. Since it can be manufactured, the manufacturing process is simple and the number of processes is small, so that the optical transceiver module 10 can be manufactured economically.
[0039]
Embodiment of optical communication system
This embodiment is an example of the embodiment of the optical communication system according to the second invention, and FIG. 8 is a perspective view showing the configuration of the communication system of this embodiment.
The optical communication system 60 according to the present embodiment includes one multi-mode optical fiber 62 and two optical transmitting and receiving modules 10 according to the first embodiment connected to both ends of the multi-mode fiber 62, namely, the first This is an optical communication system that includes an optical transmitting / receiving module 64 and a second optical transmitting / receiving module 66 and is capable of bidirectional communication.
[0040]
In the optical communication system 60 of the present embodiment, the optical signal light emitted from the surface emitting semiconductor laser element 16 of the optical signal transmitting device of the first optical transceiver module 64 is the first optical waveguide branch 14b shown in FIG. Then, the light enters the multimode fiber 62 from the optical waveguide main body 14 a through the Y branch portion 12, and is transmitted to the second optical transmitting / receiving module 66 via the multimode fiber 62.
The optical signal light transmitted to the second optical transmission / reception module 66 is received by the photodiode 18 from the optical waveguide main body 14a via the Y branch portion 12.
[0041]
Similarly, the optical signal light emitted from the surface emitting semiconductor laser element 16 of the optical signal transmission device of the second optical transmission / reception module 66 passes through the first optical waveguide branch 14b and the Y branch portion 12 from the optical waveguide main body 14a. The light enters the multimode fiber 62 and is transmitted to the first optical transceiver module 64 via the multimode fiber 62.
The optical signal light transmitted to the first optical transmission / reception module 64 is received by the photodiode 18 from the optical waveguide main body 14a via the Y branch portion 12.
[0042]
In the optical communication system 60 according to the present embodiment, simultaneous two-way communication can be performed via one multi-mode optical fiber 62. That is, not only half-duplex communication in which light propagates in one direction but also full-duplex communication in which light propagates in both directions at the same time is possible.
[0043]
【The invention's effect】
As described above, according to the present invention, a single-core multimode optical waveguide, a Y-branch, a surface-emitting semiconductor laser device provided at an end of a first optical waveguide branch, and a second optical waveguide A light receiving element provided at an end of the branch, wherein the inclined end faces of the first and second optical waveguide branches are used as a reflecting surface, and the optical signal light from the surface emitting semiconductor laser element is reflected at the inclined end face to form a core of the optical waveguide. By making the optical signal light incident on the light receiving element after being incident on the light receiving layer and reflected from the core layer at the inclined end face, it is possible to achieve simultaneous optical communication, high optical coupling efficiency, and an economical optical transceiver module. Has been realized.
Further, by providing the optical transceiver module according to the present invention at both ends of a single-core multimode optical waveguide, an optical communication system capable of simultaneous bidirectional optical communication is realized.
By employing the optical transmission / reception module according to the present invention for optical interconnection in the field of optical interconnection, an optical system such as a lens becomes unnecessary, and as a result, the construction cost of an optical interconnection system can be greatly reduced.
The method for manufacturing an optical transceiver module according to the present invention realizes a method for economically manufacturing the optical transceiver module according to the present invention.
[Brief description of the drawings]
FIG. 1 is a top view illustrating a configuration of a main part of an optical transceiver module according to an embodiment.
2A is a cross-sectional view of the optical waveguide taken along line II of FIG. 1, and FIG. 2B is a cross-sectional view of the optical waveguide taken along line II-II of FIG.
FIG. 3 is a sectional view of a main part of the optical signal transmission device taken along line III-III in FIG. 1;
FIG. 4 is a sectional view of a main part of the optical signal receiving device taken along line IV-IV in FIG. 1;
FIG. 5 is a sectional view of a main part of the optical signal receiving device taken along line IV-IV in FIG. 1;
FIGS. 6A to 6C are cross-sectional views of respective steps corresponding to the line VV in FIG. 1 when the optical transceiver module is manufactured by the method of the embodiment.
FIGS. 7D and 7E respectively correspond to the line VV in FIG. 1 when the optical transceiver module is manufactured by the method of the embodiment, following FIG. 6C. It is sectional drawing of each process.
FIG. 8 is a perspective view illustrating a configuration of a communication system according to an embodiment.
FIGS. 9A to 9C are cross-sectional views of respective steps when manufacturing a planar polymer optical waveguide according to an example of a conventional method for manufacturing a polymer optical waveguide.
[Explanation of symbols]
Reference numeral 10: optical transmission / reception module of the embodiment, 12: Y branch portion, 14: optical waveguide, 14a: optical waveguide main body, 14b: first optical waveguide branch, 14c: second optical waveguide branch , 16... Surface emitting semiconductor laser element, 18... Photodiode, 20... Module substrate, 22... Lower cladding layer, 24... Core layer, 25. ... N-type semiconductor substrate, 30 n-type DBR mirror, 32 .lambda. Resonator, 34 p-type DBR mirror, 36 end of first optical waveguide branch, 36a end face, 38 ... n-type semiconductor substrate, 40 ... n-type semiconductor layer, 42 ... i-type semiconductor layer, 44 ... p-type semiconductor layer, 46 ... end of second optical waveguide branch, 48 ... core forming layer 50 mask, 60 optical communication system of embodiment, 62 ... multimode optical fiber, 64 ...... first optical transceiver module, 64 ...... second optical transceiver modules.

Claims (7)

A single-core multi-mode optical waveguide connected to an external optical waveguide, a Y-branch that branches the optical waveguide into a first optical waveguide branch and a second optical waveguide branch, and a first optical waveguide. An optical signal transmitting device provided at an end of the waveguide branch, and an optical signal receiving device provided at an end of the second optical waveguide branch,
The first optical waveguide branch and the second optical waveguide branch each have an inclined end face obliquely intersecting the extending direction of the core layer of the optical waveguide as an end face of each end,
The optical signal transmission device has, as a light source, a surface emitting semiconductor laser element that uses the inclined end surface of the first optical waveguide branch as a reflection surface, reflects the emitted optical signal light on the inclined end surface, and makes the light signal light enter the optical waveguide,
The optical signal receiving device has an inclined end surface of the second optical waveguide branch as a reflection surface, and has a light receiving element that receives the optical signal light guided from the optical waveguide by reflecting the light at the inclined end surface. . The optical transceiver module according to claim 1, wherein the optical waveguide is a polymer optical waveguide. 3. The optical transceiver module according to claim 1, wherein an upper surface of the lower clad layer constituting the optical waveguide is flush with an emission surface of the surface emitting semiconductor laser device and a light receiving surface of the light receiving device. The optical transceiver module according to claim 1, wherein the inclined surface forms an angle of 45 ° with the extending direction of the core layer. A single-core multimode optical waveguide;
An optical communication system comprising: the optical transceiver module according to claim 1, connected to both ends of a multimode optical waveguide, and capable of bidirectional communication. . A single-core multi-mode optical waveguide connected to an external optical waveguide, a Y-branch that branches the optical waveguide into a first optical waveguide branch and a second optical waveguide branch, and a first optical waveguide. A method for manufacturing an optical transceiver module comprising: an optical signal transmitting device provided at an end of a waveguide branch; and an optical signal receiving device provided at an end of a second optical waveguide branch,
At a predetermined position on the substrate, a surface emitting semiconductor laser element as a light source of the optical signal transmitting device, and a photodiode as a light receiving element of the optical signal receiving device, or a step of creating,
Forming a lower cladding layer of the optical waveguide so that the light emitting surface of the surface emitting semiconductor laser device and the light receiving surface of the light receiving device are flush with the upper surface of the lower cladding layer;
A core forming layer is formed on the lower cladding layer, and then a mask having a predetermined optical waveguide planar shape is placed on the core forming layer, and ultraviolet light is irradiated from above the mask, and the refractive index of an area exposed from the mask is determined by the core. A region other than the exposed region is made smaller than the formation layer to form an intermediate cladding layer. Forming a second optical waveguide branch having a core layer;
Forming an upper cladding layer on the core layer and the intermediate cladding layer to form an optical waveguide, a Y-branch, a first optical waveguide branch, and a second optical waveguide branch;
An inclined end face is provided at an end of the first optical waveguide branch so that an optical signal light is made to enter the core layer of the first optical waveguide branch from the surface emitting semiconductor laser element with the inclined end face as a reflection surface, and the inclined end face is provided. Providing an inclined end surface at an end of the second optical waveguide branch so that optical signal light is incident on the photodiode from the second optical waveguide branch as a reflection surface. Method. A surface emitting semiconductor laser device and a photodiode are arranged or formed at a predetermined position on the substrate in a direction perpendicular to the substrate, and are formed at an angle of 45 ° in the extending direction of the core layers of the first and second optical waveguide branches. The method for manufacturing an optical transceiver module according to claim 6, wherein an inclined end surface is formed.

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