JP2001330746A - Optical module and its manufacturing method, and optical circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical module excellent in mass productivity and advantageous in a cost reduction. SOLUTION: In the optical module which is provided with a base 10, a waveguide composing body 20 including an optical waveguide 22 in which light propagates and a light receiving element 30, a curved part 25 which radiates light propagating the optical waveguide 22 from the optical waveguide 22 is provided in a part of the optical waveguide 22, and light 90 which is radiated by the curved part 25 is received by the light receiving element 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical module, a method for manufacturing the same, and an optical circuit device. In particular,
The present invention relates to an optical module (optical communication module) suitably used as a light receiving module.

[0002]

2. Description of the Related Art In order to develop an optical subscriber communication network in a highly information-oriented society, development of an optical active device represented by a semiconductor laser, an optical function module equipped with the active device, and the like have been advanced. In the future, by laying optical fiber in each home and spreading optical communication terminals in each home,
It is expected to expand the communication network. In order to achieve this, it is desired to realize a low-cost optical communication terminal.

A module as an optical communication terminal needs a function of receiving signal light and a function of transmitting signal light. A semiconductor laser and a light receiving element are used for each function of transmitting and receiving signal light. Various structures have been proposed today as modules for receiving and transmitting signal light. In particular, when the wavelengths of light to be received and transmitted are different, it is necessary to surely separate each light for each wavelength, and various structures of modules having such a function have been proposed. For example, Japanese Patent Application Laid-Open No. 9-211
No. 243 discloses a light receiving module having such a structure.

FIG. 22 shows a schematic configuration of a light receiving module disclosed in Japanese Patent Application Laid-Open No. 9-212243.
The light receiving module shown in FIG. 22 includes one optical waveguide 101 provided on a substrate 107, and a filter 105 having wavelength selectivity provided in the middle of the optical waveguide 101. One end of the optical waveguide 101 is connected to the substrate 10
7 is provided on the end face, and signal light is incident from the incident end 106. Optical waveguide 101
Of the light receiving element 10 provided on the substrate 107
Faces four.

A filter 105 provided on a substrate 107
Reflects light of 1.3 μm, for example, with a wavelength of 1.5 μm.
It has a function of transmitting light having a wavelength of 1.3 μm, and light having a wavelength of 1.3 μm and a wavelength of 1.5 μm enter the optical waveguide 101 from the incident end 106 in a mixed state. Of the incident light, light having a wavelength of 1.3 μm is reflected by the filter 105, and light having a wavelength of 1.5 μm passes through the filter 105 and is received by the light receiving element 104. Light receiving element 104
Is converted into an electric signal.
On the other hand, the wavelength of 1.3 μm reflected by the filter 105
m light enters the second optical waveguide 102 provided between the filter 105 and the end face of the substrate 107, and thereafter,
The light propagates through the second optical waveguide 102 and has an end surface 1 of the substrate 107.
06.

[0006]

In the conventional light receiving module shown in FIG. 22, it is necessary to insert the filter 105 into a groove provided on the substrate 107. Therefore, when manufacturing the light receiving module, a step of forming a groove for inserting the filter 105 in the substrate 107, and
A step of inserting the filter 105 into the groove is required,
Therefore, there is a problem that the manufacturing process becomes complicated and it is not possible to manufacture easily. Moreover, the filter 105
Is usually very thin, on the order of 10 μm, so that it is not easy to mechanically insert the filter 105 into the groove provided in the substrate 107, and there is a problem that the manufacturing efficiency is poor.

There has also been proposed a configuration in which a dielectric multilayer film is formed on an emission end face of a signal light in an optical waveguide, and a wavelength selecting function is realized by the dielectric multilayer film. However, in such a configuration, after a substrate on which an optical waveguide is formed is formed into a predetermined shape, a dielectric multilayer film must be formed on an end face of the substrate, as in a normal semiconductor manufacturing process. There is a problem that mass production cannot be performed efficiently.

The present invention has been made in view of the above points, and a main object of the present invention is to provide an optical module which does not require a complicated assembling process and is easy to manufacture, and a method of manufacturing the same.

[0009]

An optical module according to the present invention comprises a base, a waveguide structure including an optical waveguide on the base and through which light propagates, and a light receiving element. A curved portion for emitting light propagating through the optical waveguide from the optical waveguide is provided in a part, and the light receiving element receives the light emitted by the curved portion.

In one embodiment, a step portion including an inclined surface is provided on a part of the base, and the curved portion of the optical waveguide is a portion where the optical waveguide is curved by the step portion. The light emitted from the optical waveguide is reflected by the inclined surface of the step and received by the light receiving element.

In one embodiment, the optical waveguide is:
The inclined surface is formed in a groove provided in the base, and the inclined surface is located in the groove.

[0012] It is preferable that a concave portion is provided near the lower portion of the inclined surface of the base, for curving the optical waveguide downward.

[0013] In one embodiment, it is preferable that the inclined surface of the step portion is concavely concave so as to converge reflected light to the light receiving element.

The optical waveguide does not extend to a height exceeding the upper end of the inclined surface, and the end of the optical waveguide is within a range between the height of the upper end and the height of the lower end of the inclined surface. Is preferred.

It is preferable that the width of the groove increases from a lower portion to an upper portion of the inclined surface.

[0016] The refractive index of the substrate constituting the inclined surface is lower than the refractive index of the optical waveguide.
It is preferable that the light guide is disposed in the groove under a condition of totally reflecting light emitted from the optical waveguide.

It is preferable that a reflecting film for reflecting light emitted from the optical waveguide is formed on the surface of the inclined surface.

In one embodiment, a diffraction grating is formed on the surface of the inclined surface.

In one embodiment, a dielectric multilayer film formed by laminating layers having different dielectric constants is formed on the surface of the inclined surface.

In one embodiment, the optical waveguide is:
A protrusion or a depression is formed in a groove provided in the base, and a part of the bottom surface of the groove is formed to bend the optical waveguide upward or downward. The light source is provided at a position where light emitted from the curved portion formed by the portion or the concave portion reaches.

In one embodiment, a plurality of the protrusions or the depressions are provided for one optical waveguide, and the plurality of protrusions or the depressions correspond to the plurality of the protrusions or the depressions.
A plurality of the light receiving elements are provided.

In one embodiment, the light receiving device further includes a light condensing member for condensing light, and the light condensing member collects light emitted by the curved portion and received by the light receiving element. Light, the light receiving element, via the light collecting member,
Receives the collected light.

In one embodiment, the light-condensing member comprises:
It is selected from the group consisting of a convex lens, a concave lens, and a Fresnel lens.

In one embodiment, the light collecting member is
It is a member having a light-condensing function and made of a material having a refractive index different from the refractive index around the light-condensing member.

In one embodiment, the optical device further comprises an optical function member for selectively transmitting or absorbing light of a specific wavelength, wherein the optical function member is a dielectric multilayer formed by laminating layers having different dielectric constants. A light receiving element that receives the light emitted by the curved portion via the optical function member.

In one embodiment, the optical device further includes an optical function member that selectively transmits or absorbs light of a specific wavelength, and the optical function member is made of a material that absorbs only the specific wavelength. The light receiving element receives light emitted by the bending portion via the optical function member.

[0027] In one embodiment, a light shielding portion for shielding light is provided around the inclined surface, and the light shielding portion blocks light reflected and scattered by the inclined surface.

Preferably, the light shielding portion is made of a light absorbing material.

The light shielding portion may be a groove provided in the base.

Another optical module according to the present invention comprises a base, a waveguide structure including an optical waveguide disposed on the base and through which light propagates, and a light receiving element, wherein the optical waveguide comprises the optical waveguide. Has an end face for emitting light that has propagated from the optical waveguide, and on the base, an inclined surface that reflects light emitted from the end face to the light receiving element is provided, and the light receiving element is The light reflected by the inclined surface is received.

In one embodiment, a medium made of a material that absorbs light of a specific wavelength is provided between the inclined surface and the light receiving element.

In one embodiment, a light shielding portion for blocking light is provided around the inclined surface, and the light shielding portion blocks light reflected and scattered by the inclined surface.

An optical circuit device according to the present invention is an optical circuit device comprising a light source, an optical waveguide for transmitting light emitted from the light source, and a light receiving element.
A curved portion for emitting light propagating through the optical waveguide from the optical waveguide is provided, and the light receiving element receives the light emitted by the curved portion.

In one embodiment, the light source is a semiconductor laser element, the optical waveguide is a planar optical waveguide, and the light receiving element is a photodiode, and the light source, the optical waveguide and the light receiving element are , Provided on a platform, thereby forming an optical integrated circuit, wherein the optical integrated circuit further includes at least one selected from the group consisting of a splitter, an optical multiplexer / demultiplexer, a semiconductor amplifier, a switch, and a modulator. Have.

The method for manufacturing an optical module according to the present invention comprises:
A step of preparing a substrate, a step of forming, on the upper surface of the substrate, a groove including a wall surface in which the wall surface of the groove serving as one end of the groove is an inclined surface inclined with respect to the normal to the substrate, and the bottom surface of the groove And a material forming the cladding layer and a material forming the optical waveguide are sequentially deposited on the inclined surface, whereby the light guide having a curved portion at the step formed by the bottom surface of the groove and the inclined surface is formed. The method includes a step of forming a waveguide and a step of providing a light receiving element for receiving light emitted by the curved portion of the optical waveguide at a position on the substrate surface where the light reaches.

In one embodiment, the step of preparing the substrate is a step of preparing a semiconductor substrate, and the step of forming the groove includes a step of performing an anisotropic etching process on the substrate. The material constituting the optical waveguide is
It is a polymer material.

In one embodiment, the step of preparing the substrate is a step of preparing a glass substrate. After the step of forming the groove and before the step of forming the optical waveguide, the step of preparing the substrate is performed on the inclined surface. The step of forming a reflective film is performed.

[0038]

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings,
For the sake of brevity, components having substantially the same function are denoted by the same reference numerals. Note that the present invention is not limited to the following embodiments. (Embodiment 1) An optical module according to an embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 2 schematically shows a cross-sectional structure of the optical module along the longitudinal direction of the optical waveguide, and FIG. 2 schematically shows a cross-sectional structure of the optical module along line II-II in FIG. FIG.
FIG. 3 is a perspective view for explaining a configuration of an optical waveguide.

The optical module according to the present embodiment has a base 10 and a waveguide structure 20 disposed on the base 10 and including an optical waveguide 22 for transmitting light. The base 10 in the present embodiment is a silicon substrate made of silicon, and the waveguide structure 20 is
1, each layer of the optical waveguide (core) 22 and the upper cladding 23 is laminated in order from the bottom. Optical waveguide 22
Is set to be slightly higher than the refractive indices of the lower and upper claddings 21 and 23 surrounding the optical waveguide 22, and of the light incident on the optical waveguide 22,
The interface between the cladding 2 and the claddings 21 and 23 that satisfies the condition of total reflection propagates through the optical waveguide 22.

A part of the optical waveguide 22 is provided with a curved portion 25 for emitting light propagating through the optical waveguide 22 from the optical waveguide 22. Light (optical signal) 90 emitted from the optical waveguide 22 by the bending portion 25 is received by the light receiving element 30 provided on the upper clad 23, and thereafter,
Converted to electrical signals. The light receiving element 30 is composed of, for example, a photodiode. The term “curved portion” used in this specification includes not only a curved portion but also a bent portion.

In this embodiment, the step 15 including the inclined surface 12 is formed on a part of the substrate 10, and the curved part 25 of the optical waveguide 22 is formed by the step 15. In other words, the curved portion 25 of the optical waveguide 22 is
This is a portion where the optical waveguide 22 is curved by the step portion 15. Light 9 emitted from the optical waveguide 22 by the curved portion 25
0 is reflected on the inclined surface 12 of the step portion 15 and the light receiving element 3
0 is received. Thus, the optical waveguide 22 and the light receiving element 30 in the optical module of the present embodiment are optically coupled to each other.

In this embodiment, a smooth inclined surface 12 is formed by exposing the (111) plane of silicon by utilizing the etching anisotropy of the silicon substrate 10. When the inclined surface 12 is formed smoothly, in other words, when the inclined surface 12 is formed in a mirror-like shape, the scattering of the signal light 90 reflected by the inclined surface 12 can be suppressed, so that the light receiving element 30 can reliably receive light. As a result, the signal light propagating in the optical waveguide 22 can be efficiently received by the light receiving element 30.

Further, a wavelength filter can be formed on the surface of the inclined surface 12. In such a configuration, since it is possible to selectively reflect only a specific wavelength, it can be suitably used as a duplexer in wavelength division multiplex communication. In the case where a wavelength filter is formed on the surface of the inclined surface 12, the step of mechanically inserting the filter 105 into the groove of the substrate 107 shown in FIG. 22 can be omitted, so that manufacturing efficiency can be improved. Become. As the wavelength filter formed on the inclined surface 12, a dielectric multilayer film in which layers having different dielectric constants are stacked can be used. Further, a diffraction grating may be formed on the surface of the inclined surface 12.

The substrate 10 has a groove 11 formed therein.
In the groove 11, a portion of the optical waveguide 2 where light propagates
2 are formed. When the optical waveguide 22 is located in the groove 11, the following advantages are obtained. That is, the signal light 90 radiated from the optical waveguide 22 by the bending portion 25
Is scattered by various factors and emitted in various directions. However, as in the present embodiment, the optical waveguide 22 is
When it is located inside, the scattered light of the optical signal radiated from the optical waveguide 22 can be confined in the groove 11, so that it can be prevented from being scattered to the surroundings. As a result, the scattered light can be prevented from being received by the optical components arranged around the substrate 10, and the effect of the optical signal on other optical components arranged around the substrate 10 can be effectively eliminated. be able to. Further, since the groove 11 in the present embodiment is selectively formed in a relatively narrow portion near the surface of the substrate 10, the optical waveguide 2 is formed in the groove 11.
In the step after the formation of 2, the advantage that the surface of the upper clad 23, which is the surface of the waveguide structure 20, can be easily flattened is also obtained.

In the optical module according to the present embodiment, the wall surface of the groove, which is one end of the groove 11, emits the radiated light 90 from the optical waveguide 22.
Is configured as an inclined surface 12 that reflects light. In addition,
The other end (not shown) of the groove 11 is exposed from an end surface (side surface) of the substrate 10 and is an open end. Groove 11
Is formed, for example, by etching the substrate 10, and in the present embodiment, the groove 11 is configured such that its cross section has an inverted trapezoidal shape. In the present embodiment, the groove 11 is formed by etching.
The present invention is not limited to this, and the grooves 11 may be formed by physical processing.

In the case where the inverted trapezoidal groove 11 is formed as in this embodiment, the angle formed by the wall surface 13 along the longitudinal direction of the groove 11 and the upper surface 10a of the substrate, and the angle between the wall surface 13 and the bottom surface 14 of the substrate. Can be made an obtuse angle, so that the waveguide structure 20 (21, 22, 23) can be easily formed by spin coating. The wall surface 13 may be inclined by 10 ° to 60 ° with respect to the normal line of the substrate 10. The groove 11 may be formed in a rectangular shape by making the wall surface 13 substantially vertical, instead of inclining the wall surface 13 to form the inverted trapezoidal groove 11.

The waveguide structure 20 according to the present embodiment comprises:
It is formed by depositing an organic material (polymer material) on the substrate 10 by spin coating. The lower cladding 21 serving as a lower layer of the waveguide structure 20 includes a bottom surface 14 of the groove,
It is formed so as to cover the wall surface 13, the inclined surface 12, and the upper surface 10a of the substrate. An optical waveguide (core) having a substantially rectangular cross section is provided on the lower clad 21 located on the bottom surface 14 of the groove.
The upper cladding 23 is formed on the lower cladding 21 so as to cover the optical waveguide 22. The upper surface of the upper clad 23 is flat, and the light receiving element 30 is disposed on the upper surface of the upper clad 23 located on the optical waveguide 22 (or on the groove 11). The light receiving element 30 used in the present embodiment is
It has a size of about 300 μm along the width direction of the optical waveguide 22 and about 300 μm along the longitudinal direction of the optical waveguide 22.

Lower cladding 2 on bottom surface 14 of groove 11
1, the thickness of the optical waveguide 22 and the thickness of the upper cladding 23 are as follows:
For example, it is set to be equal to or larger than the spot size of the propagating light. The thicknesses of the lower cladding 21 and the optical waveguide 22 on the inclined surface 12 become thinner from the lower side to the upper side.
The thickness of the lower cladding 21 and the optical waveguide 22 on the upper surface 10a of the substrate 10 located above
In consideration of the materials of the claddings 21 and 23, the dimensions are set so as not to satisfy the cutoff condition of the light to be propagated.
The thickness of the upper cladding 23 also decreases from the lower side of the inclined surface 12 to the upper side, and the upper surface 10 a
The thickness of the upper clad 23 is also set to a size that does not satisfy the above cut-off condition.

In the present embodiment, since the optical waveguide 22 is formed by the spin coating method, the optical waveguide 22 is drawn by a gentle arc near the inclined surface 12 under the influence of the inclined surface 12, It is curved along 12. That is, the curved portion 25 is formed in the step portion 15. If the spin coating method is used, the curved portion 25 can be formed easily and easily, but is not limited to the spin coating method. For example, even when using a deposition method or a sputtering method,
Although it is more complicated than in the case of the spin coating method,
It is possible to form

As a material of the core layer constituting the optical waveguide 22, various known materials can be used. In the present embodiment, the core layer is composed of an organic material, and examples of the material include polymer materials such as (1) vinyl organic molecules, (2) siloxane skeleton polymers, and (3) polycondensation organic molecules. Is mentioned. Not only organic materials,
A core layer made of a multi-component glass, a semiconductor material, a quartz glass, or the like may be formed.

The (1) vinyl-based organic molecules include polymethyl methacrylate (PMMA), fluorinated PMM
A, deuterated PMMA, crosslinked PMMA, alicyclic group-introduced modified PMMA, polyethyl methacrylate, and the like, and copolymers of these with other vinyl compounds can also be used. As the siloxane skeleton polymer (2), various modified polysiloxanes can be used,
For example, a photosensitive polysiloxane derivative, a modified fluorinated polysiloxane, and the like can be given. As the above-mentioned (3) polycondensation-based organic molecules, various modified polymers modified by using a condensation polymer such as fluorinated polyimide, thermosetting polyester, or polycarbonate as a skeleton can be used. And epoxy-modified polyester resin, acryl-modified polycarbonate and the like, and copolymers containing them and derivatives thereof. Further, fluorinated polyimide, fluorinated polymethacrylate, or fluorinated polysiloxane can also be used. On the other hand, as a material of the cladding layers constituting the lower and upper claddings 21 and 23, for example, poly (methyl fluoride methacrylate) can be mentioned.

In the optical module of the present embodiment, a curved portion 25 is provided in a part of the optical waveguide 22, light propagating through the optical waveguide 22 is emitted from the optical waveguide 22 by the curved portion 25, and the emitted light is received by the light receiving element. It is configured to receive light at 30. Therefore, an optical module excellent in mass productivity and assemblability can be realized. That is, it becomes possible to mass-produce optical modules efficiently, as in a normal semiconductor manufacturing process.

FIG. 4 shows a light receiving element 30 having a wavelength of 1.3.
4 schematically shows the top configuration of the optical module of the present embodiment when a light receiving element for μm or 1.55 μm is used. FIG. 4 shows only the optical waveguide 22 formed in the groove 11 for simplicity, and shows the upper clad 23.
And the groove 11 are omitted. On the other hand, FIG. 5 shows a case where the optical waveguide 22 is branched and the light receiving elements 30a for 1.3 μm and 1..
A configuration in which a light receiving element 30b for 55 μm is provided is shown.

Further, instead of the configuration in which the optical waveguide 22 shown in FIG. 5 is branched, a configuration in which the diffraction grating 100 is formed on the inclined surface 12 as shown in FIG. 6 can be used. In the case of this configuration, light having a plurality of wavelengths (for example, λ1, λ2) propagating in the optical waveguide 22 is emitted from the optical waveguide 22 at the curved portion 25, and the emitted light is
Thus, the light is diffracted at different angles for each wavelength, and is received by a plurality of light receiving elements 30a and 30b provided on the upper cladding 23, respectively. For example, λ1 is 1.3 μm
When λ2 is 1.55 μm, the signal light of λ1 is received by the 1.3 μm light receiving element 30a.
The diffraction grating may be configured so that the 1.55 μm light receiving element 30b receives the second signal light.

Next, a method for manufacturing the optical module according to the present embodiment will be described with reference to FIGS. FIGS. 7A to 7E are process cross-sectional views illustrating the method for manufacturing an optical module according to the present embodiment.

First, after a silicon substrate is prepared as the substrate 10, a photoresist film 51 is formed on a part of the upper surface 10a of the substrate 10, as shown in FIG.

Next, as shown in FIG. 7B, etching is performed using the photoresist film 51 as a mask, thereby forming a step 15 including the inclined surface 12 on the substrate 10. The inclined surface 12 is formed by performing anisotropic dry etching using the etching anisotropy of the silicon substrate 10 so that the (111) plane of silicon is exposed. Since the etching rate of the (111) plane of silicon is lower than that of other planes, it is possible to perform highly anisotropic etching processing such that the plane is selectively exposed. In this step, the groove 11 that defines the optical path of the optical waveguide 22 is also formed together with the formation of the inclined surface 12.

In this embodiment, a silicon substrate is used as the substrate 10, but another substrate may be used. When a diamond-type substrate such as a silicon substrate or a zinc-blende-type crystal structure substrate (such as a GaAs substrate) is used, a specific surface can be selectively exposed by anisotropic etching. Smoothly inclined surface 1
2 can be formed. Of course, the inclined surface 12 may be formed by using a known processing method (for example, physical processing such as laser processing) without using anisotropic etching. In that case, the type of the substrate is not particularly limited, and a glass substrate or a metal substrate may be used. In the case of a glass substrate, processing can be performed using, for example, hydrofluoric acid. In the case of a metal substrate, when the metal has excellent malleability, processing such as press processing can be performed.

At least a portion of the substrate 10 that forms the inclined surface 12 is the optical waveguide 22 (or the waveguide structure 2).
It is preferable to use a material having a refractive index lower than 0). In the present embodiment, the substrate 10 is made of a low refractive index material. In the case of such a configuration, the optical waveguide 22
Signal light emitted from the inclined surface 12 can be reflected well. Further, when the inclination angle of the inclined surface 12 is set so that the signal light emitted from the optical waveguide 22 is totally reflected, the signal light can be efficiently reflected by the inclined surface 12. As a result, the light receiving efficiency of the light receiving element 30 can be improved.

Further, even if the inclined surface 12 is not made of a material having a lower refractive index than the optical waveguide 22, the reflection film (for example, a metal film) is formed on the surface of the inclined surface 12 so that the reflection by the inclined surface 12 is achieved. Can be improved.
When a glass substrate is used as the substrate 10, the inclined surface 1
It is preferable to form a reflective film on the surface of No. 2. In this case, after forming the structure shown in FIG. 7B, a photoresist film (not shown) is formed on the region of the substrate 10 except for the inclined surface 12, and then the exposed surface of the inclined surface 12 is formed. A reflective film may be formed on the substrate.

When a metal film is formed as the reflection film, the method is not particularly limited as long as a flat metal film can be formed. For example, an evaporation method or a sputtering method can be used. In the case of a configuration in which a reflective film is formed, the material of the substrate 10 is not particularly limited to a low refractive index material, so that the range of material selection is widened. In addition, in the case of the substrate 10 made of metal, the same effect as the configuration in which the reflection film is formed on the surface of the inclined surface 12 can be obtained.

When it is desired to provide a function of wavelength selectivity to the inclined surface 12, after forming the inclined surface 12, a diffraction grating is formed on the inclined surface 12 by using a known technique, or the inclined surface 12 is formed. A dielectric multilayer film may be formed on the surface of the substrate 12.

Next, after removing the photoresist 51,
As shown in FIG. 7C, the inclined surface 12 and the bottom surface 1 of the groove 11 are formed.
A material (for example, polymethyl methacrylate) constituting the lower clad layer 21 is deposited on the substrate 10 by a spin coating method so as to cover the substrate 4 and the wall surface 13.

Next, as shown in FIG. 7D, a material (polymer material) forming the core layer (optical waveguide) 22 is deposited on the lower cladding layer 21 by spin coating. Next, a photoresist (not shown) that defines the shape of the core layer 22 is provided thereon, and etching is performed using the photoresist as a mask to obtain the core layer 22 having a substantially rectangular cross-sectional shape (FIG. 2). Since the core layer 22 is also formed on the lower clad layer 21 in the step portion 15 including the inclined surface 12 by the spin coating method, the curved portion 25 is formed at this position. That is, under the influence of the inclined portion 12, the core layer 22 curves along the inclined surface 12 by drawing a gentle arc in the vicinity of the inclined surface 12, thereby forming a curved portion on a part of the core layer 22. 25 are formed. In addition, from the viewpoint of manufacturing efficiency, it is preferable to use the spin coating method. However, as long as the curved portion 25 is simply formed, a deposition method, a sputtering method, or the like may be used instead of the spin coating.

Next, as shown in FIG.
A material constituting the upper cladding layer 23 (for example, polymethyl methacrylate) is deposited on the lower cladding layer 21 so as to cover the lower cladding layer 2 by spin coating, and the upper cladding layer 23 having a flat upper surface is obtained. The upper surface of the upper cladding layer 23 becomes the upper surface of the waveguide structure 20.

Thereafter, when the light receiving element 30 is provided on the upper surface of the upper cladding layer 23 at a position where the light reflected by the inclined surface 12 reaches, the optical module of the present embodiment is obtained. The light receiving element 30 used in the present embodiment is a photodiode, and the groove 11 is viewed from above the optical module.
Are arranged in the region where. For example, when viewed from above the optical module, the light receiving element 30 is positioned such that the light receiving portion of the light receiving element 30 is located on the region where the core layer 22 is formed.
Is arranged. The photodiode serving as the light receiving element 30 in the present embodiment is a pin diode as shown in FIG. The pin diode shown in FIG.
On a P substrate 32, an n ⁺ -InP layer 33, an n ⁺ -InP layer (buffer layer), an i-InGaAs layer 34, and an n ⁻ -In
A structure in which P layer 35 are laminated in this ^order, n - -InP layer 35
And a Zn diffusion layer (light receiving portion) 31 that is in contact with the i-InGaAs layer 34. The surface on which the Zn diffusion layer 31 is formed faces the upper surface of the upper cladding layer 23.

According to the manufacturing method of this embodiment, the above-described optical module of this embodiment can be efficiently mass-produced as in a normal semiconductor manufacturing process. Therefore, a low-cost optical module can be provided.

Since the optical module of the present embodiment is configured as a planar optical waveguide (PLC), it also has the advantage that it can be manufactured more compactly than discrete or fiber optical components. That is, it is possible to provide an optical component (optical waveguide element) capable of meeting the demand for miniaturization. Since the PLC is also excellent in terms of integration and function enhancement, by utilizing this advantage, a light source (semiconductor laser) is further provided in the optical module of the present embodiment, and hybrid integration of an optical transmitting / receiving module or the like is performed. It is also possible to use a circuit device (optical circuit device). That is, it is possible to realize not only the light receiving module but also the optical transmitting and receiving module. Further, there is provided an optical circuit device in which at least one of a light source, a splitter, an optical multiplexer / demultiplexer, a semiconductor amplifier, a switch, and a modulator is mounted on the platform using the substrate 10 of the present embodiment as a PLC platform. Can also. In addition,
Of course, these components including the light source may be mounted on a portion other than the substrate 10 to realize the optical circuit device. Embodiment 2 An optical module according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 9 schematically illustrates a cross-sectional configuration of the optical module according to the present embodiment.

The optical module of the present embodiment has the inclined surface 12
The optical module of the first embodiment is different from the optical module of the first embodiment in that a concave portion 16 is provided near the lower part of the optical module. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In this embodiment, since the concave portion 16 is provided near the lower portion of the inclined surface 12, the optical waveguide 22 can be curved downward. A part of the curved portion 25 formed by the influence of the inclined surface 12 can be made to protrude downward so as to be more greatly curved. Therefore, most of the optical signals propagating in the optical waveguide 22 are
Can be radiated toward the inclined surface (reflection surface) 12 from above, so that the amount of light reflected by the inclined surface 12 can be increased. That is, since more signal light can be emitted from the optical waveguide 22 to increase the amount of signal light received by the light receiving element 30, the light receiving element 3
It is possible to improve the conversion efficiency of an optical signal into an electrical signal at 0.

In this embodiment, the concave portion 16 for bending the optical waveguide 22 downward is provided at a position where the bottom surface 14 of the groove and the inclined surface 12 join. That is, the inclined surface 12 is extended further below the level of the bottom surface 14 of the groove, and the inclined surface 12
The concave portion 16 is formed on the bottom surface 14 of the groove.
Is formed. In order to form the concave portion 16 along the inclined surface 12, the following may be performed. For example, after fabricating the structure shown in FIG. 7B, the region other than the region where the concave portion 16 is formed is masked with a photoresist, and then the unmasked portion is etched to form the concave portion 16.
After the formation of the recess 16, by performing the same steps as those shown in FIGS. 7C and 7D, it is possible to obtain the optical waveguide 22 in which the bending portion 25 is further bent downward.

In this embodiment, the cross-sectional shape of the concave portion 16 along the longitudinal direction of the optical waveguide 22 is an inverted trapezoidal shape. However, the present invention is not limited to this, and the shape can be such that the optical waveguide 22 can be curved downward. (For example, a hemisphere).
Considering the case where the lower cladding layer 21 is formed by using the spin coating method, the inclined surface 12 and the wall surface of the concave portion 16 are flush, and the angle formed between the wall surface of the concave portion 16 and the bottom surface 14 of the groove 11 is obtuse. Is preferable because the polymer material can be coated well. Embodiment 1
As described above, a diffraction grating or the like can be formed on the inclined surface 12, and the configuration shown in FIG. 6 can be applied to the optical module of the present embodiment. Embodiment 3 An optical module according to Embodiment 3 of the present invention will be described with reference to FIG. FIG.
1 schematically illustrates a cross-sectional configuration of an optical module according to the present embodiment.

The optical module according to the present embodiment has the reflected light 90
Is different from the optical module of the first embodiment in that it has an inclined surface 12 that is depressed so as to condense light onto the light receiving element 30. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In the present embodiment, the reflected light 90 is
Since the inclined surface 12 is formed to have a concave shape so as to be condensed to zero, radiation light 90 from the optical waveguide 22 can be reflected by the inclined surface 12 so as to be in a condensed state. The reflected light 90 in the condensed state can be received by the light receiving element 30. Therefore, the light receiving efficiency of the light receiving element 30 can be further improved. In this embodiment, the concave inclined surface (reflection surface) 12 is formed so that the inclination angle of the inclined surface 12 changes intermittently. In order to form such an inclined surface 12, masking is performed on portions other than the portion to be etched, and anisotropic etching may be performed a plurality of times so that the inclination angles are different. Also, of course, the concave inclined surface 12 may be formed by physical processing.

In this embodiment, the concave inclined surface 12 is formed such that the inclination angle of the inclined surface 12 changes intermittently. However, the present invention is not limited to this. 12 may be formed. Furthermore, the configuration in which the inclined surface 12 is recessed along the inclination direction has been described.
However, the configuration is not limited to this, and a configuration in which the optical waveguide 22 is concavely recessed along the width direction may be employed, or a configuration in which both are combined may be employed. In addition, the configuration of the present embodiment and the configuration of the first or second embodiment can be appropriately combined. Embodiment 4 An optical module according to Embodiment 4 of the present invention will be described with reference to FIG. FIG.
1 schematically illustrates a cross-sectional configuration of an optical module according to the present embodiment.

The optical module of this embodiment differs from the optical module of the first embodiment in that the optical waveguide 22 is interrupted in the groove 11. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In the present embodiment, the optical waveguide 22 is configured to be interrupted in the groove 11. More specifically, the optical waveguide 22 does not extend to a height exceeding the upper end of the inclined surface 12, and the end of the optical waveguide 22 is located in a range between the height of the upper end and the height of the lower end of the inclined surface 12. ing. Thus, even when the optical waveguide 22 is interrupted in the middle of the inclined surface 12, the signal light propagating in the optical waveguide 22 is emitted from the optical waveguide 22 toward the inclined surface 12 by the bending portion 25, Next, after being reflected by the inclined surface 12, the reflected light 90 is received by the light receiving element 30. Even if the optical waveguide 22 does not extend to the upper surface 10a of the substrate 10 and is interrupted in the middle as in the present embodiment, it can be operated without any particular problem. In addition, in the case of this configuration, all of the signal light propagating in the optical waveguide 22 can be emitted toward the inclined surface 12, so that the light amount of the signal light 90 reflected toward the light receiving element 30 can be further increased. Can be.

In the present embodiment, the thickness of the optical waveguide 22 is gradually reduced from the lower side to the upper side of the inclined surface 12. For example, after the structure shown in FIG. 7D is manufactured, a step of etching unnecessary portions of the optical waveguide (core layer) 22 may be additionally performed. Further, not only etching but also physical processing may be performed. In addition, the configuration of the present embodiment is different from the above-described first to fourth embodiments.
Can be further appropriately combined. Embodiment 5 An optical module according to Embodiment 5 of the present invention will be described with reference to FIG. FIG.
1 schematically illustrates a cross-sectional configuration of an optical module according to the present embodiment.

The optical module of the present embodiment has the optical waveguide 2
2 is different from the optical module of the first embodiment in that the light propagating through 2 is emitted from the end face of the optical waveguide 22 and the emitted light is reflected by the inclined surface 12. That is, in the above embodiment, the optical waveguide 2 is
In this embodiment, the signal light is emitted from the light guide 2, but in the present embodiment, instead of providing the curved portion 25, the end face 20 a for emitting the light propagating through the optical waveguide 22 from the optical waveguide 22.
Is formed. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In this embodiment, the end face 20 a of the waveguide structure 20 is located in the groove 11, and the end face 20 a of the waveguide structure 20 is substantially perpendicular to the bottom surface 14 of the groove 11. It is formed as follows. End surface 20a and inclined surface 12
A suitable space is provided between the two, and a uniform medium (for example, air) 80 is filled therein. Since the end surface 20a and the inclined surface 12 face each other, the light propagating through the optical waveguide 22 exits from the end surface 20a and is reflected by the inclined surface 12, and then the reflected light 90 is reflected by the light receiving element 30. The light is received and converted into an electric signal by the light receiving element 30.

In the case where the end face 20 a is provided as described above, all of the signal light propagating through the optical waveguide 22 can be emitted from the end face 20 a of the optical waveguide 22. Since the emitted signal light (guided light) 90 propagates in the homogeneous medium 80 having no interface, the light receiving element 30 can reliably receive the light without scattering. Therefore, it is possible to prevent the signal light from being scattered and radiated to the surroundings, and as a result, it is possible to reduce optical noise to surrounding optical elements.

When the signal light propagates in the optical waveguide 22 in, for example, a Gaussian mode, light can be received by the light receiving element 30 without changing the mode of the signal light. The design of the coupling structure with the light receiving element 30 is facilitated. In the present embodiment, since air is used as the uniform medium 80, there is only a gap between the end surface 20a and the inclined surface 12, and the light emitted from the end surface 20a and the reflected light 90 from the inclined surface 12 are provided. Pass through the air as a uniform medium. That is, a space that is not filled with a special substance is used as a uniform medium. As the uniform medium 80, of course, a medium such as quartz glass or organic glass can be used.

When a medium composed of a material that absorbs light of a specific wavelength is used as the uniform medium 80,
The homogeneous medium 80 can be provided with optical functionality called wavelength selectivity. As a result, the signal light having different wavelengths propagating in the optical waveguide 22 is wavelength-selected and the light receiving element 30 is selected.
It is possible to execute a high-level process of receiving light at the. In addition, it is also possible to form a diffraction grating or a dielectric multilayer film on the inclined surface 12 as in the first embodiment. Embodiment 6 An optical module according to Embodiment 6 of the present invention will be described with reference to FIG. FIG.
FIG. 3 is a perspective view schematically showing a configuration of an optical waveguide 22 and a groove 11 of the optical module according to the embodiment.

The optical module according to this embodiment has the inclined surface 12
Groove 1 widens from bottom to top
1 is different from the optical module of the first embodiment. That is, in the optical module of the present embodiment, the width of the groove 11 is gradually increased in the vicinity 11 a of the inclined surface 12 as approaching the upper end of the inclined surface 12. Are formed in a tapered shape in the vicinity of the inclined surface. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In the case of the configuration in which the width of the groove 11 is widened in the vicinity 11a of the inclined surface 12 as in the present embodiment, the optical waveguide 22 disposed inside the groove 11 is formed by spin coating, dry etching or the like. Then, slope 1
The shape can be changed so that the width dimension of the optical waveguide 22 is increased in the vicinity 11a of the second portion 2. The shape varies depending on the forming conditions and the like. For example, as shown in FIG.
In a, the shape can be gradually increased as approaching the inclined surface 12. With such a shape, the signal light radiated from the optical waveguide 22 can be increased, and thus the light receiving efficiency of the light receiving element 30 can be improved.

In the present embodiment, the shape of the optical waveguide 22 is changed by increasing the width of the groove 11 in the vicinity of the inclined surface 12. However, the configuration can increase the width of the optical waveguide 22. For example, the shape of the groove 11 is not particularly limited. Embodiment 7 An optical module according to Embodiment 7 of the present invention will be described with reference to FIG. FIG.
1 schematically illustrates a cross-sectional configuration of an optical module according to the present embodiment.

The optical module according to the present embodiment is different from the optical module according to the first embodiment in that a projection 17 for curving the optical waveguide 22 upward is formed on a part of the bottom surface 14 of the groove 11. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In the case where the projection 17 is formed, the optical waveguide 22 is curved by the projection 17 so as to project upward. Due to the curved portion 25, a part of the optical signal propagating through the optical waveguide 22 is radiated upward. A light receiving element 30 is provided at a position where the signal light 90 emitted from the bending portion 25 reaches, and the emitted light 90 is received by the light receiving element 30 and converted into an electric signal. In the present embodiment, the light receiving element 30 is disposed on the upper clad 23 located above the curved portion 25.
The protrusion 17 is provided on the bottom surface 14 of the groove 11 so as to cross the groove 11, and the cross-sectional shape of the protrusion 17 along the longitudinal direction of the optical waveguide 22 is a triangle (for example, an isosceles triangle). It is.

Unlike the first embodiment, the light 90 emitted from the optical waveguide 22 is directly reflected by the light receiving element 30 without being reflected by the inclined surface 12. For this reason, the optical waveguide 22 and the light receiving element can be optically coupled with a simple configuration without considering the influence of the reflection by the inclined surface 12. In the configuration of the first embodiment, the optical signal propagating in the optical waveguide 22 in only one direction is used, whereas in the configuration of the present embodiment, the optical signal propagating in any direction is used. Can also be used.

In addition, since the signal light propagating in the optical waveguide 22 after passing through the curved portion 25 can be further used, a plurality of protrusions 17 can be provided for one optical waveguide 22.
Also, a plurality of light receiving elements 30 can be provided.
In such a configuration, if the radiated light 90 from each curved portion 25 generated by each projection 17 is received by each light receiving element 30 via a filter having wavelength selectivity, It becomes possible to select the wavelength of the signal light having different wavelengths propagating in the optical waveguide 22 and receive the light with each light receiving element 30. Accordingly, an optical device for an optical multiplex communication system (optical device for WDM) can be realized with a simple configuration.

In the present embodiment, the projection 17 having a triangular cross section is shown, but the present invention is not limited to this. Optical waveguide 22
The shape of the protruding portion 17 is not particularly limited as long as the shape can deform the optical waveguide 22 so that the signal light is emitted from the optical waveguide 22. The inclined surface forming the projection 17 does not have to be a smooth surface, but any or all of the surfaces may be concavely depressed, or a step-like step may be provided. Furthermore, when the cross-sectional shape is a left-right symmetrical shape such as an isosceles triangle, the light receiving efficiency of each optical signal propagating in both directions can be made substantially the same. The light receiving efficiency of each optical signal propagating in both directions can be made different by intentionally making the cross-sectional shape asymmetric.

Further, the concave portion 16 of the second embodiment (see FIG. 9) may be provided in the vicinity of the projecting portion 17 so that the curved portion 25 is further curved. Such a recess 1
By providing 6, the amount of signal light radiated from the optical waveguide 22 can be increased. The recess 16
It can be provided on both sides or any one side in the propagation direction of the signal light. In the case where the recesses 16 are provided on both sides of the protrusion 17, if the shape obtained by combining the protrusion 17 and the recesses 16 located on both sides is made symmetrical, as described above, each of the optical signals propagating in both directions can be obtained. The light receiving efficiencies can be substantially the same. In addition, as long as the optical waveguide 22 can be deformed so as to emit signal light from the optical waveguide 22, the shape is not limited to the protrusion 17, but may be a depression. Embodiment 8 An optical module according to Embodiment 8 of the present invention will be described with reference to FIG. FIG.
Light receiving element 30 in optical module according to the present embodiment
The cross-sectional configuration of the periphery is schematically shown.

The optical module according to the present embodiment has
The optical module according to the first embodiment is different from the optical module according to the first embodiment in that the light receiving element 30 receives the light condensed through the optical module 1. The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In this embodiment, since the light condensing member 41 for condensing the signal light (including the reflected light) radiated from the optical waveguide 22 is provided, the signal light radiated from the optical waveguide 22 is received by the light receiving element 30. The signal light can be condensed by the light condensing member 41 even if the signal light is diffused due to a long distance until the light reaches. Therefore, even in such a case, the light receiving element 30
Light can be received efficiently.

FIG. 15 shows a configuration in which a convex lens (convex lens structure) 41 is used as a light-collecting member between the waveguide structure 20 (or the upper clad 23) and the light receiving element 30. Between the convex lens 41 and the light receiving element 30,
A uniform medium 80 is provided, and the uniform medium 80 is, for example, matching oil. Further, the same material as that of the upper clad 23 may be used. Further, the uniform medium 80 may be air, and in this case, a space may be provided between the convex lens 41 and the light receiving element 30 using an appropriate support member (not shown).

Although the convex lens 41 is used in the configuration shown in FIG. 15, the present invention is not limited to this, and a concave lens (concave lens structure) may be used. As shown in FIG. 16, a Fresnel lens (Fresnel lens structure) 42 may be used instead of the convex lens 41. A “Fresnel lens” is a lens on a plane that utilizes a light diffraction phenomenon. When such a Fresnel lens 42 is provided, the signal light radiated from the optical waveguide 22 is collected by the Fresnel lens 42, propagates through the uniform medium 80, and is received by the light receiving element 30. As described above, the uniform medium 80
May be air.

In the case of the structure using the Fresnel lens 42 as the light condensing member, the projection amount is small and flat as compared with the structure using the convex lens 41 shown in FIG.
Subsequent processes such as assembly of the light receiving element 30 can be easily performed. Further, since the Fresnel lens 42 can be realized by forming a predetermined pattern on the surface of the upper clad 23, there is an advantage that the Fresnel lens 42 can be easily manufactured.

Further, as shown in FIG.
A low-refractive-index portion 43 made of a material lower than the refractive index of the surrounding upper clad 23 is formed on the surface portion of the upper clad 23 facing the lower clad 23, and this low-refractive-index portion 43 may function as a light collecting member. It is possible. The low refractive index portion 43
It can be formed by performing a method such as ion implantation and impurity diffusion on the upper cladding 23 so that the refractive index is lower than that of the surroundings. The signal light emitted from the optical waveguide 22 is collected by the low-refractive-index portion 43,
The light is efficiently received by the light receiving element 30 through the medium 80. Also in this configuration, since the surface of the upper clad 23 is flat, subsequent processes such as assembly of the light receiving element 30 are facilitated. There is also an advantage that it can be easily manufactured. Embodiment 9 An optical module according to Embodiment 9 of the present invention will be described with reference to FIG. FIG.
Light receiving element 30 in optical module according to the present embodiment
The cross-sectional configuration of the periphery is schematically shown.

The optical module of this embodiment is different from that of the above-described embodiment in that an optical functional member 50 for selectively transmitting or absorbing light of a specific wavelength is formed between the light receiving element 30 and the upper clad 23. Different from one optical module.
The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In this embodiment, as the optical function member 50,
A dielectric multilayer film in which layers having different dielectric constants are periodically laminated is used. When the dielectric multilayer film 50 is designed to reflect only light having a wavelength of, for example, 1.55 μm, it can function as follows. For example, even if optical signals having wavelengths of 1.3 μm and 1.55 μm propagate in the optical waveguide 22 in a mixed state and are reflected on the inclined surface 12, the wavelengths of 1.55 μm and 1.55 μm are reached before reaching the light receiving element 30.
Is reflected by the dielectric multilayer film 50. For this reason,
The signal light having the wavelength of 1.55 μm is not received by the light receiving element 30. On the other hand, the signal light having a wavelength of 1.3 μm passes through the dielectric multilayer film 50 and can be received by the light receiving element 30. As described above, when the dielectric multilayer film 50 as the optical function member is provided, an optical module capable of selecting the wavelength of the optical signal received by the light receiving element 30 can be provided.

In this embodiment, since the dielectric multilayer film 50 serving as a filter is provided on the upper surface of the upper clad 23, the filter structure is formed on the upper surface of the waveguide structure 20 when the waveguide structure 20 is in a wafer state. Dielectric multilayer film 50
Can be easily provided. In other words, a reflection filter can be formed on the waveguide structure 20 in a state where the waveguide structure 20 is formed on the substrate 10. On the other hand, in the case of the conventional configuration shown in FIG.
In order to provide the filter 105 at right angles to the
7, it is necessary to insert a filter into the slit groove, or, on the end face of the optical waveguide 101,
It was necessary to deposit a substance to be a filter. According to the configuration of the present embodiment, since there is no such need,
An optical module excellent in mass productivity can be realized.

In this embodiment, the dielectric multilayer film 50 is used as the optical function member, but the present invention is not limited to this. For example, a material that absorbs light of a predetermined wavelength is coated with the upper cladding 2.
An optical functional member having wavelength selectivity can be formed by depositing it on the upper surface of the optical element 3. Also in this case, since the optical function member can be formed on the surface of the waveguide structure 20 in a wafer state, mass productivity is excellent. Moreover, when a resin is used as the light absorbing material, the optical functional member can be formed by a simple method of applying the resin onto the waveguide structure 20 in a wafer state. Further, the light receiving element 30 is disposed with an appropriate gap provided with respect to the surface of the upper clad 23, and an optical functional member is formed by inserting a resin having an appropriate wavelength selectivity into the gap. Is also good.

As described above, according to the configuration of the present embodiment,
Since the light receiving element 30 is disposed above the waveguide structure 20, functions such as wavelength selectivity can be easily provided. Therefore, an optical module (optical circuit device) having an advanced optical function can be obtained without impairing the excellent mass productivity achievable by the semiconductor manufacturing process.

It is to be noted that the present invention is not limited to the configuration in which the optical function member 50 is provided between the upper surface of the upper clad 23 and the light receiving element 30, but it is also possible to adopt a configuration in which the upper clad 23 itself has light functionality. To achieve such a configuration, for example, the upper cladding 2 is made of a material that absorbs light of a predetermined wavelength.
3 may be configured. In this configuration, the upper cladding 2
The light having the wavelength absorbed by 3 is sequentially attenuated while the signal light propagates through the optical waveguide 22. And the optical waveguide 2
The signal light radiated from the second curved portion 25 and reflected by the inclined surface 12, or while the signal light directly radiated to the upper clad 23 propagates again in the upper clad 23, the light of the wavelength is further increased. Will attenuate. As a result, only light other than the wavelength component absorbed by the upper cladding 23 is received by the light receiving element 30. As described above, by providing the upper clad 23 with the optical functionality, the signal light can be transmitted in both the waveguide mode in which the signal light propagates in the optical waveguide 22 and the radiation mode in which the signal light propagates in the upper clad 23. Can be modulated.

The configuration of the present embodiment may be such that the light receiving element 30 receives the reflected light 90 by the inclined surface 12 as shown in the above-described first to sixth embodiments, or the configuration shown in the above-described seventh embodiment. The light emitted from the optical waveguide 22 is received by the light receiving element 3
A configuration in which 0 directly receives light may be used. Embodiment 10 An optical module according to Embodiment 10 of the present invention will be described with reference to FIG. FIG.
1 schematically illustrates a cross-sectional configuration around the light receiving element 30 in the optical module according to the present embodiment.

In the optical module of the present embodiment, the light-shielding portion 60 having the window portion 61 for transmitting light
The optical module according to the first embodiment is different from the optical module according to the first embodiment in that the optical module is provided on the surface 0 (the surface of the upper clad 23).
The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In the present embodiment, since the light shielding portion 60 having the window portion 61 at the center is formed on the surface of the upper clad 23, the signal light radiated from the optical waveguide 22 and propagated in the upper clad 23 is: The light is emitted only from the window 61 of the light shielding unit 60, and is received by the light receiving element 30 via the uniform medium 80. Therefore, it is possible to prevent the signal light from being irradiated on the light receiving element 30 other than the predetermined light receiving section 31. As a result, it is possible to avoid the occurrence of a current component that slows down the response speed of the light receiving element 30 due to light being incident on a portion of the light receiving element 30 other than the light receiving section 31 where no electric field is applied. 30 can be prevented from deteriorating.

The light-shielding portion 60 of the present embodiment can be formed by using a known technique such as metal deposition and sputtering. The configuration according to the present embodiment is the same as that of the first embodiment.
6, the light receiving element 30 may receive the reflected light 90 by the inclined surface 12, or the light emitted from the optical waveguide 22 shown in the seventh embodiment may be used as the light receiving element 30.
May directly receive light. In addition, the light shielding unit 60
The medium 80 between the light receiving element 30 and the light receiving element 30 may be air. Embodiment 11 An optical module according to Embodiment 11 of the present invention will be described with reference to FIG. FIG.
FIG. 3 is a perspective view schematically showing a configuration around the optical waveguide 22 and the inclined surface 12 in the optical module according to the present embodiment.

The optical module according to the present embodiment has the inclined surface 12
Is different from the optical module of the first embodiment in that a light shielding part 70 for shielding light is provided around the optical module.
The other configuration is the same as that of the first embodiment, and the description is omitted or simplified.

In the present embodiment, the light shielding portion 70 is provided on the upper surface 10a of the substrate located around the inclined surface 12, and the light shielding portion 70 is formed of a light absorbing resin or the like. In addition, the light shielding portion 70 extends linearly in parallel with the upper end of the end surface (inclined surface 12) of the groove 11, and linearly extends from both ends of the portion along the wall surface 13 of the groove 11. And a so-called "U-shaped" shape.

In this embodiment, since the U-shaped light shielding portion 70 is formed around the inclined surface 12, the following effects can be obtained. When the signal light propagating in the optical waveguide 22 disposed in the groove 11 is emitted from the curved portion 25 and reflected on the inclined surface 12, the signal light travels in various directions around the light other than the light traveling toward the upper light receiving element 30. Scattered light is also scattered. In the present embodiment, such scattered light can be absorbed by the light shielding portion 70 made of, for example, a light absorbing resin. As a result, it is possible to prevent the scattered light from propagating in the waveguide structure 20 or the substrate 10 and thereby adversely affect the other optical components disposed therearound as optical noise. Can be.

In the present embodiment, the light shielding portion 70 made of a light absorbing resin is provided. However, the present invention is not limited to this. As shown in FIG.
It is also possible to form the light shielding part by forming the groove part 71 in 0a. That is, the light shielding portion may be configured by the space in the groove portion 71. Even with the light shielding portion 71 having such a structure, the same effect as the light shielding portion 70 made of a light absorbing resin or the like can be obtained. Further, since the light shielding portion of the groove portion 71 can be formed by simply etching the substrate 10, there is an advantage that the light shielding portion can be easily formed. In addition, by combining the light shielding portion 70 made of a light absorbing resin or the like and the light shielding portion 71 made of a groove, the effect of absorbing scattered light can be further increased.

In the case where the light shielding portion has a configuration in which the light is reflected by the inclined surface 12 as in the first embodiment, the inclined surface 1
2, but in the case of the configuration as in the seventh embodiment (see FIG. 14), the light shielding portion is provided on the substrate 10 located around the protrusion 17 formed on the bottom surface of the groove 11. May be formed.

Although the present invention has been described with reference to the first to eleventh embodiments, each of the first to eleventh embodiments can be arbitrarily combined with each other as necessary. In the above-described embodiment, the configuration in which the waveguide structure 20 is disposed on the substrate 10 has been described. However, even when an arbitrary layer is provided between the substrate 10 and the waveguide structure 20, the above description has been made. The effect can be obtained similarly. Further, the configurations of the first to eleventh embodiments can be suitably applied not only to the light receiving module but also to the light transmitting and receiving module. According to the above-described embodiment, since an optical module excellent in mass productivity can be provided, a low-cost optical communication terminal can be realized, and as a result, the development of an optical subscriber communication network in an advanced information society can be realized. Can contribute.

[0115]

According to the present invention, it is possible to provide an optical module in which a curved portion is provided in a part of an optical waveguide and a light receiving element receives light emitted by the curved portion.
Therefore, it is possible to provide an optical module which is excellent in mass productivity and advantageous in reducing costs.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a cross-sectional configuration of an optical module according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an optical waveguide 2 of the optical module according to the first embodiment.
FIG. 2 is a perspective view schematically showing the configuration of No. 2;

FIG. 4 is a top view schematically showing the configuration of the optical module according to the first embodiment.

FIG. 5 is a top view for explaining a modification of the configuration shown in FIG. 4;

FIG. 6 is a cross-sectional view illustrating a modified example of the configuration of the optical module according to the first embodiment.

FIGS. 7A to 7E are process cross-sectional views illustrating the method for manufacturing the optical module according to the first embodiment.

FIG. 8 is a cross-sectional view schematically illustrating a configuration of a light receiving element 30.

FIG. 9 is a cross-sectional view schematically illustrating a configuration of an optical module according to a second embodiment.

FIG. 10 is a cross-sectional view schematically illustrating a configuration of an optical module according to a third embodiment.

FIG. 11 is a cross-sectional view schematically illustrating a configuration of an optical module according to a fourth embodiment.

FIG. 12 is a cross-sectional view schematically illustrating a configuration of an optical module according to a fifth embodiment.

FIG. 13 is a perspective view schematically showing a configuration of an optical waveguide 22 of the optical module according to the sixth embodiment.

FIG. 14 is a cross-sectional view schematically illustrating a configuration of an optical module according to a seventh embodiment.

FIG. 15 is a cross-sectional view schematically illustrating a configuration around a light receiving element 30 of the optical module according to the eighth embodiment.

FIG. 16 is a cross-sectional view schematically illustrating a configuration around a light receiving element 30 of the optical module according to the eighth embodiment.

FIG. 17 is a cross-sectional view schematically illustrating a configuration around a light receiving element 30 of the optical module according to the eighth embodiment.

FIG. 18 is a cross-sectional view schematically illustrating a configuration around a light receiving element 30 of the optical module according to the ninth embodiment.

FIG. 19 is a cross-sectional view schematically illustrating a configuration around a light receiving element 30 of the optical module according to the tenth embodiment.

FIG. 20 is a perspective view schematically showing a configuration around an optical waveguide 22 and an inclined surface 12 in the optical module according to the eleventh embodiment.

FIG. 21 is a perspective view schematically showing a configuration around an optical waveguide 22 and an inclined surface 12 in the optical module according to the eleventh embodiment.

FIG. 22 is a top view schematically showing a configuration of a conventional optical module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate (substrate) 11 Groove 12 Slope (reflection surface) 13 Wall surface of groove 14 Bottom of groove 15 Step portion 16 Concave portion 17 Projection portion 20 Waveguide structure 21 Lower clad 22 Optical waveguide (core) 23 Upper clad 25 Curved portion (Bent part) 30 Light receiving element 31 Light receiving part 41 Convex lens 42 Fresnel lens 50 Optical functional member (dielectric multilayer film) 60 Transmission window 70, 71 Light shielding part 80 Medium

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Kito 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 2H037 AA01 BA02 BA03 BA11 BA12 BA23 BA24 BA25 CA12 CA33 CA38 CA39 DA03 DA05 DA06 2H047 KA04 KA11 KB09 LA09 LA11 LA18 MA03 MA07 PA24 PA28 QA05 QA07 RA08 TA43 5F088 AA03 AB07 BA20 BB01 CB14 EA11 EA20 JA03 JA11 JA12

Claims (29)

[Claims] 1. A light-receiving element, comprising: a base; a waveguide structure disposed on the base and including an optical waveguide through which light propagates; and a light receiving element; An optical module, comprising: a curved portion that emits light to be emitted from the optical waveguide; and the light receiving element receives the light emitted by the curved portion. 2. A step portion including an inclined surface is provided on a part of the base, wherein the curved portion of the optical waveguide is a portion where the optical waveguide is curved by the step portion, The optical module according to claim 1, wherein the light emitted from the wave path is reflected by the inclined surface of the step portion and received by the light receiving element. 3. The optical module according to claim 2, wherein the optical waveguide is formed in a groove provided in the base, and the inclined surface is located in the groove. 4. The optical module according to claim 2, wherein a concave portion that curves the optical waveguide downward is provided near a lower portion of the inclined surface of the base. 5. The optical module according to claim 2, wherein the inclined surface of the step portion is concavely concave so as to collect reflected light to the light receiving element. 6. The optical waveguide does not extend to a height exceeding the upper end of the inclined surface, and the end of the optical waveguide is set within a range between the height of the upper end and the height of the lower end of the inclined surface. The optical module according to claim 2, wherein: 7. The optical module according to claim 2, wherein the groove becomes wider from a lower portion to an upper portion of the inclined surface. 8. The refractive index of a part of the base constituting the inclined surface is lower than the refractive index of the optical waveguide, and the inclined surface is provided with the groove under a condition of totally reflecting light emitted from the optical waveguide. The optical module according to claim 2, wherein the optical module is disposed in the optical module. 9. A reflection film which reflects light emitted from an optical waveguide is formed on a surface of the inclined surface.
An optical module according to item 1. 10. The optical module according to claim 2, wherein a diffraction grating is formed on a surface of the inclined surface. 11. The optical module according to claim 2, wherein a dielectric multilayer film formed by laminating layers having different dielectric constants is formed on the surface of the inclined surface. 12. The optical waveguide is formed in a groove provided in the base, and a projection or a depression that curves the optical waveguide upward or downward is formed on a part of a bottom surface of the groove. The optical module according to claim 1, wherein the light receiving element is provided at a position where light emitted from the curved portion formed by the protrusion or the recess reaches. 13. A plurality of protrusions or depressions are provided for one optical waveguide, and a plurality of light receiving elements are provided corresponding to the plurality of protrusions or depressions. The optical module according to claim 13, which is provided. 14. A light condensing member for condensing light, wherein the light condensing member condenses light emitted by the curved portion and received by the light receiving element, The optical module according to claim 1, wherein the light receiving element receives the collected light via the light collecting member. 15. The light-collecting member is selected from the group consisting of a convex lens, a concave lens, and a Fresnel lens.
The optical module according to claim 14. 16. The optical module according to claim 14, wherein the light-condensing member is a member having a light-condensing function and made of a material having a refractive index different from a refractive index around the light-condensing member. 17. An optical functional member for selectively transmitting or absorbing light of a specific wavelength, wherein the optical functional member is a dielectric multilayer film in which layers having different dielectric constants are stacked, The optical module according to claim 1, wherein the light receiving element receives light emitted by the bending portion via the optical function member. 18. A light-receiving element, comprising: an optical function member that selectively transmits or absorbs light of a specific wavelength; wherein the optical function member is made of a material that absorbs only a specific wavelength; The optical module according to claim 1, wherein the optical module receives light emitted by the bending portion via the optical function member. 19. The method according to claim 2, wherein a light shielding portion for shielding light is provided around the inclined surface, and the light shielding portion shields light reflected and scattered on the inclined surface. An optical module as described. 20. The optical module according to claim 19, wherein the light shielding portion is made of a material that absorbs light. 21. The optical module according to claim 19, wherein the light shielding portion is a groove provided in the base. 22. A base, a waveguide structure including an optical waveguide on which light propagates, and a light-receiving element, wherein the optical waveguide receives light propagating through the optical waveguide. An end surface for emitting light from the optical waveguide; and an inclined surface for reflecting the light emitted from the end surface to the light receiving element, on the base, wherein the light receiving element is reflected by the inclined surface. An optical module that receives reflected light. 23. The optical module according to claim 22, wherein a medium made of a material that absorbs light of a specific wavelength is provided between the inclined surface and the light receiving element. 24. A light shielding unit for shielding light around the inclined surface, wherein the light shielding unit shields light reflected and scattered on the inclined surface. 24. The optical module according to 23. 25. An optical circuit device comprising: a light source; an optical waveguide for transmitting light emitted from the light source; and a light receiving element, wherein the optical waveguide receives light propagating through the optical waveguide. An optical circuit device, comprising: a curved portion that emits light from the optical waveguide; and the light receiving element receives light emitted by the curved portion. 26. The light source is a semiconductor laser device,
The optical waveguide is a planar optical waveguide, and the light receiving element is a photodiode, and the light source, the optical waveguide, and the light receiving element are provided on a platform, thereby forming an optical integrated circuit. The optical circuit device according to claim 25, wherein the optical integrated circuit further includes at least one selected from the group consisting of a splitter, an optical multiplexer / demultiplexer, a semiconductor amplifier, a switch, and a modulator. 27. A step of preparing a substrate, and a step of forming a groove on the upper surface of the substrate, the groove including a wall surface in which the wall surface of the groove as one end of the groove is inclined with respect to the normal line of the substrate. A material forming the cladding layer and a material forming the optical waveguide are sequentially deposited on the bottom surface and the inclined surface of the groove, thereby forming a step formed from the bottom surface of the groove and the inclined surface. Forming an optical waveguide having a curved portion; and providing a light receiving element for receiving light emitted by the curved portion of the optical waveguide at a position in the substrate surface where the light reaches. A method of manufacturing an optical module. 28. The step of preparing the substrate, the step of preparing a semiconductor substrate, the step of forming the groove includes a step of performing an anisotropic etching process on the substrate, The method for manufacturing an optical module according to claim 28, wherein the constituent material is a polymer material. 29. The step of preparing a substrate is a step of preparing a glass substrate. After the step of forming the groove and before the step of forming the optical waveguide, a reflective film is formed on the inclined surface. The method for manufacturing an optical module according to claim 27, wherein the step of forming is performed.