JP2005300954A - Bidirectional optical communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise utilization efficiency of light while eliminating shielding of the light and to transmit signals bidirectionally and to transmit a signal having multiple wavelengths. <P>SOLUTION: This bidirectional communication can eliminate the shielding of the light by a mirror and can raise the utilization efficiency of the light in bidirectional optical communication by using a truncated pyramid-shaped mirror 4 which has a plurality of reflecting surfaces 8a, 8b, etc, which roughly totally reflect transmission light emitted from light emitting elements 3a, 3b,.. and make them be coupled to an optical fiber 1 and has a cavity part 9 which guides a reception light emitted from the optical fiber 1 to a light receiving element for separating the transmission light from the reception light and also can transmit a signal having multiple wavelengths by using the plurality of the reflecting surfaces 8a, 8b, etc., of the truncated pyramid-shaped mirror 4. . <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bidirectional optical communication apparatus that performs transmission and reception using a single optical fiber. More specifically, using a multimode optical fiber such as a plastic optical fiber as a transmission medium, home communication, communication within an electronic device, communication between electronic devices, communication within an electronic device, communication between electronic devices, LAN (Local Area Network) ) And the like.

  Conventionally, in an optical communication apparatus that transmits and receives signal light (transmission light, reception light) using an optical fiber as a transmission medium, many methods for coupling an optical fiber with a light emitting element and a light receiving element have been proposed. At this time, the bidirectional system in which transmission and reception are communicated using one optical fiber is advantageous in view of the cost of installing the optical fiber, compared to the case where transmission and reception are performed by one independent optical fiber. In some cases, several methods have been proposed.

  In such a bidirectional optical communication apparatus that performs transmission / reception using a single optical fiber, a method of separating transmission light and reception light and combining them with an optical fiber is an issue. Therefore, conventionally proposed methods include those using holograms, mirrors, and half mirrors. For example, according to Patent Document 1, a method using two mirrors is proposed. The content is that the transmitted light radiated from the light emitting element is reflected by the first mirror in the direction of the optical fiber end face and coupled with the optical fiber, while the received light propagating through the optical fiber is reflected by the curved second mirror. The light is condensed on the light receiving element. The optical fiber is premised on the use of a plastic optical fiber (hereinafter referred to as POF) whose core diameter can be increased from 200 μm to 1 mm as compared with a silica-based optical fiber.

JP 2001-235660 A

  The optical communication device has an increasing communication capacity year by year, and multi-wavelength communication that uses multiple wavelengths is also common. This increases the cost of laying the optical fiber, and has the advantage of increasing the transmission capacity per line and reducing the cost.

  However, the method disclosed in Patent Document 1 cannot cope with the increase in wavelength, and only one transmission / reception signal can be transmitted with one optical fiber. In addition, since a part of the mirror blocks light, there is a problem that the light use efficiency is lowered.

  An object of the present invention is to make it possible to transmit light in both directions and to transmit a multi-wavelength signal without blocking light, increasing light utilization efficiency.

  One of the other purposes is to suppress the lateral expansion of the device and to reduce the size.

  Another object is to enable the use of a small light receiving element and to increase the communication speed.

  Another purpose is to reduce the manufacturing cost of the entire device.

  Another purpose is to reduce the time required for implementation.

  The invention according to claim 1 is a bidirectional optical communication apparatus that performs transmission / reception using a single optical fiber, wherein the plurality of light emitting elements, the light receiving elements, and the transmission light emitted from the light emitting elements are substantially totally reflected, and And a truncated pyramid mirror having a plurality of reflecting surfaces coupled to an optical fiber and a hollow portion for guiding the received light emitted from the optical fiber to the light receiving element.

  According to a second aspect of the present invention, in the bidirectional optical communication device according to the first aspect, the hollow portion opens at an angle larger than a radiation angle of the optical fiber.

  According to a third aspect of the present invention, in the bidirectional optical communication device according to the first or second aspect, the light emitting element is configured such that the transmitted light emitted is substantially totally reflected by the corresponding reflecting surface of the truncated pyramid mirror. It arrange | positions so that it may inject into an optical fiber.

  According to a fourth aspect of the present invention, in the bidirectional optical communication apparatus according to the third aspect, the truncated pyramid mirror and the light emitting element are disposed on the same layer, and the light receiving element is disposed on another layer. Yes.

  According to a fifth aspect of the present invention, in the bidirectional optical communication device according to any one of the first to fourth aspects, the received light emitted from the optical fiber is disposed in the cavity of the truncated pyramid mirror. A lens for condensing light on the light receiving element is provided.

  According to a sixth aspect of the present invention, in the bidirectional optical communication apparatus according to the first aspect, the plurality of light emitting elements radiate transmission light having different wavelengths.

  The invention according to claim 7 is the bidirectional optical communication device according to claim 6, wherein the truncated pyramid mirror and the plurality of light emitting elements are disposed on the same layer, and the plurality of light receiving elements are disposed on different layers. Is arranged.

  According to an eighth aspect of the present invention, in the bi-directional optical communication apparatus according to the seventh aspect, an optical element having wavelength selectivity is provided in the front stage on the incident side of the plurality of light receiving elements.

  According to a ninth aspect of the present invention, in the bidirectional optical communication apparatus according to the seventh aspect of the present invention, the received light emitted from the optical fiber is collected on the light receiving element, which is disposed in the cavity of the truncated pyramid mirror. A lens to be lit, and an optical element having wavelength selectivity disposed between the lens and the plurality of light receiving elements.

  According to a tenth aspect of the present invention, in the bidirectional optical communication device according to the ninth aspect, the lens and the optical element are integrally formed of a hologram.

  An eleventh aspect of the present invention is the bidirectional optical communication device according to any one of the first to tenth aspects, further comprising an alignment structure for aligning a positional relationship between the optical fiber and the truncated pyramid mirror.

  The invention according to claim 12 is the bidirectional optical communication device according to any one of claims 1 to 11, wherein the reflection surface has a high reflectance with respect to the wavelength of the transmission light emitted by the light emitting element, The truncated pyramid mirror itself, the lens, or the optical element having wavelength selectivity is all transmissive to the wavelength of the received light.

  A thirteenth aspect of the present invention is the bidirectional optical communication device according to any one of the first to twelfth aspects, wherein the truncated pyramid shaped mirror and the light emission are provided on a substrate on which the truncated pyramid shaped mirror and the light emitting element are arranged. A mark for positioning the element is provided.

  According to the first to third aspects of the invention, by using the truncated pyramid mirror, the light is not blocked by the mirror, the light use efficiency of bidirectional optical communication can be increased, and the truncated pyramid mirror Multi-wavelength signals can also be sent by using a plurality of reflective surfaces.

  According to the invention described in claim 4, since the layer in which the light emitting element is disposed and the layer in which the light receiving element is disposed are separate and independent layers, the lateral spread of the device can be reduced. The size of the apparatus can be reduced.

  According to the fifth aspect of the present invention, the received light is collected by the lens and received by the light receiving element, whereby a small light receiving element can be used, and thus the communication speed can be increased.

  According to the invention described in claim 6, since the truncated pyramid-shaped mirror having a plurality of reflecting surfaces is used, and the light emitting elements that emit transmission light having different wavelengths are arranged on each reflecting surface, the same as one wavelength. Wavelength multiplex communication can be performed with a size of about, and the light utilization efficiency of bidirectional communication can be increased.

  According to the seventh aspect of the present invention, since the layer on which the plurality of light emitting elements are arranged and the layer on which the plurality of light receiving elements are arranged are separate layers, the lateral spread of the device can be reduced. Therefore, the apparatus can be reduced in size.

  According to the eighth aspect of the invention, since the optical element having wavelength selectivity is arranged, the wavelength can be divided at the front stage of the plurality of light receiving elements, and the light can be received more efficiently.

  According to the ninth aspect of the invention, the size of the light receiving element can be reduced by combining an optical element having wavelength selectivity and a lens, and high-speed wavelength division multiplexing communication is possible.

  In the tenth aspect of the present invention, since the optical element having a wavelength selectivity and the lens are integrally formed as a hologram, these parts can be combined into one, and the apparatus can be miniaturized.

  According to the eleventh aspect of the present invention, since the positioning structure is provided, the optical fiber and the truncated pyramid mirror can be easily aligned, and the manufacturing cost of the entire apparatus can be suppressed.

  In the invention described in claim 12, by using a basically transparent material except for the reflecting surface, a pyramid-shaped mirror, a lens, or an optical element having wavelength selectivity is formed on one substrate using a semiconductor fabrication process. It is possible to manufacture them integrally, and it is possible to provide a large amount of highly accurate products at a low cost.

  According to the invention of claim 13, by providing a positioning mark indicating the arrangement of the truncated pyramid mirror and the light emitting element on the substrate in advance, the position of the mirror and the light emitting element is aligned with the mark. Even if the light emitting element is not actually made to emit light, it can be adjusted accurately, the time required for mounting can be reduced, and a highly accurate one can be provided at low cost.

  The best mode for carrying out the present invention will be described with reference to the drawings.

[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a part of a configuration of a bidirectional optical communication apparatus that performs transmission and reception using one optical fiber according to the present embodiment, and FIG. 2 is a plan view of a part thereof. The bidirectional optical communication apparatus according to the present embodiment schematically includes one optical fiber 1 and a plurality of, for example, three light-emitting elements disposed on the substrate 2 near the end of the optical fiber 1. 3a, 3b, 3c, a truncated pyramid mirror 4 and a light receiving element 6 disposed on another substrate 5.

  As the optical fiber 1, for example, a multimode optical fiber such as POF is used. In the POF, the core 1a is made of a plastic having excellent light transmittance such as PMMA (Polymethy Metha Acrylate) or polycarbonate, and the clad 1b is made of a plastic having a refractive index lower than that of the core 1a.

  The light-emitting elements 3a, 3b, and 3c are edge-emitting semiconductor lasers that convert an electrical signal into an optical signal, and are made of GaAlAs, GaInAlP, GaInNAs, or the like, and laser beams having different wavelengths λ1, λ2, and λ3, respectively. Is transmitted as transmitted light. These light emitting elements 3a, 3b, 3c are arranged on the submounts 7a, 7b, 7c. These submounts 7a, 7b, and 7c function to release heat generated from the semiconductor laser (light emitting elements 3a, 3b, and 3c). For example, aluminum nitride (AlN), SiC, Si, or the like is used. .

  The truncated pyramid-shaped mirror 4 is shaped so that the apex of the triangular pyramid is dropped as a whole, and the transmitted light is almost totally reflected on the outer surface (basically, it is totally reflected, but not necessarily 100% completely. It has three reflecting surfaces 8a, 8b, and 8c that are coupled to the optical fiber 1 by being reflected), and the inside is configured as a hollow portion 9 having a hole larger than the radiation angle of the optical fiber 1. ing. Each of the reflecting surfaces 8a, 8b, 8c of the truncated pyramid-shaped mirror 4 may be a plane mirror as shown in FIG. 3 (a) or a concave mirror as shown in FIG. 3 (b). I do not care. In any case, such a truncated pyramid-shaped mirror 4 is formed by depositing aluminum or the like on the surface after glass is formed to form the reflecting surfaces 8a, 8b, 8c, or by directly cutting an aluminum material. You may make it produce the truncated pyramid-shaped mirror 4 which has the reflective surfaces 8a, 8b, 8c and the cavity part 9. FIG.

  In addition, positioning marks 10 and 11 are provided on the substrate 2 in advance to make the positional relationship between the truncated pyramid mirror 4 and the light emitting elements 3a, 3b, and 3c accurate. Accordingly, the truncated pyramid mirror 4 may be disposed on the substrate 2 in accordance with the positioning mark 10. Further, the light emitting elements 3a, 3b, 3c are arranged on the substrate 2 in accordance with the positioning marks 11, so that they face the corresponding reflecting surfaces 8a, 8b, 8c, and are emitted from the respective light emitting elements 3a, 3b, 3c. The transmission light is positioned so as to be totally reflected by the corresponding reflecting surfaces 8 a, 8 b, 8 c and to enter the optical fiber 1.

  The light receiving element 6 converts the intensity of the received modulated light (received light) into an electric signal, and a photodiode having high sensitivity in the wavelength region of the light emitting element 3, for example, a PIN photodiode made of silicon, an avalanche photodiode, or the like Is used.

  As the substrates 2 and 5 on which the light emitting elements 3a, 3b and 3c and the light receiving element 6 are mounted, for example, a Si substrate is used. At this time, an opening 2a is formed so that the portion of the truncated pyramid mirror 4 in the substrate 2 transmits light. The two substrates 2 and 5 are bonded to each other with a spacer (not shown). Therefore, in the present embodiment, the truncated pyramid mirror 4 and the light emitting elements 3a, 3b, 3c are arranged on the same layer in the substrate 2, and the light receiving element 6 is arranged on another layer in the substrate 5. It has a two-layer structure.

  The transmitted light from the light emitting elements 3a, 3b, 3c must be incident on the optical fiber 1 at an incident angle smaller than the numerical aperture NA of the optical fiber 1 from the viewpoint of light loss. What is necessary is just to squeeze light with the lens etc. after radiating | emitting from element 3a, 3b, 3c, and to make it inject with the incident angle smaller than the numerical aperture NA of the optical fiber 1. The light emitting elements 3a, 3b, and 3c may be a surface light emitting type instead of an end surface light emitting type, but are arranged so as to have an incident angle smaller than the numerical aperture NA of the optical fiber 1 described above.

  In such a configuration, a transmission / reception operation will be described. First, information to be transmitted is input as an electric signal to an electronic circuit (not shown) that drives the light emitting elements 3a, 3b, or 3c. When the driving current from the electronic circuit is input to the light emitting elements 3a, 3b, or 3c, the light emitting elements 3a, 3b, or 3c emit laser light as transmission light as light modulated according to the signal. The emitted light is substantially totally reflected by the corresponding reflecting surface 8a, 8b or 8c on the outer surface of the truncated pyramid mirror 4 and enters the optical fiber 1. The incident light propagates through the core 1a of the optical fiber 1 and reaches the destination for communication.

  On the other hand, the light emitted from the other end and propagating through the optical fiber 1 is emitted at the end of the optical fiber 1 with a divergence angle corresponding to the numerical aperture NA of the optical fiber 1. This light enters the light receiving element 6 through the hollow portion 9 of the truncated pyramid mirror 4. The light receiving element 6 converts it into an electric signal in accordance with the incident modulated optical signal (received light), is input to an amplifier circuit (not shown), is amplified, and is input to the processing circuit.

  In this way, bidirectional optical communication is performed. At this time, even if two lights pass through the optical fiber 1 at the same time, the optical signal propagates without being affected.

  According to the present embodiment, by using the truncated pyramid mirror 4 for separating the transmitted light and the received light, the light is not blocked by the mirror, and the light utilization efficiency of bidirectional optical communication can be increased. In addition, by using the plurality of reflecting surfaces 8a, 8b, and 8c of the truncated pyramid mirror 4, a multi-wavelength signal can be transmitted. At this time, structurally, the layer in which the light emitting elements 3a, 3b, and 3c are arranged and the layer in which the light receiving element 6 is arranged are formed as separate layers, so that the lateral spread of the bidirectional optical communication device is increased. Therefore, the apparatus can be reduced in size. Further, using the truncated pyramid-shaped mirror 4 having a plurality of reflecting surfaces 8a, 8b, 8c, light emitting elements 3a, 3b, 3c for emitting transmission light having different wavelengths are arranged on the reflecting surfaces 8a, 8b, 8c. As a result, wavelength multiplex communication can be performed with the same size as one wavelength, and the light utilization efficiency of bidirectional communication can be increased.

  Further, by providing the substrate 2 with positioning marks 10 and 11 indicating the arrangement of the truncated pyramid mirror 4 and the light emitting elements 3a, 3b and 3c in advance, the truncated pyramid mirror 4 and the light emitting element 3a. , 3b, 3c can be aligned accurately without actually causing the light emitting elements 3a, 3b, 3c to emit light by aligning the positions with the positioning marks 10, 11, and the time required for mounting can be reduced, High precision can be provided at low cost.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. The same parts as those shown in the first embodiment are denoted by the same reference numerals, and description thereof is also omitted (the same applies to the following embodiments). FIG. 4 is a cross-sectional view showing a part of the configuration of a bidirectional optical communication apparatus that performs transmission and reception using one optical fiber according to the present embodiment, FIG. 5 is a plan view of the part, and FIG. It is a top view which shows the arrangement | positioning relationship with an element.

The bidirectional optical communication apparatus of the present embodiment is also an embodiment of wavelength multiplexing communication of, for example, three wavelengths (λ ₁ , λ ₂ , λ ₃ ). Note that these three wavelength intervals are about several nm to several tens of nm.

Basically, it conforms to the configuration of the first embodiment described above, but in this embodiment, the individual light receiving elements respectively corresponding to the _three wavelengths (λ ₁ , λ ₂ , λ ₃ ) on the substrate 5. Elements 6a, 6b, and 6c are provided. A lens 21 for condensing the received light emitted from the optical fiber 1 side on the light receiving element 6 is disposed at the top of the cavity 9 of the truncated pyramid mirror 4. Further, three wavelengths (λ ₁ , λ ₂ , λ ₃ ) are separated between the lens 21 and the light receiving elements 6a, 6b, 6c and formed on the corresponding light receiving elements 6a, 6b, 6c. A diffraction grating (optical element having wavelength selectivity) 22 is disposed. The diffraction grating 22 has a small pitch interval so as to increase the diffraction angle. As shown in FIG. 6, the light receiving elements 6a, 6b, and 6c are separately arranged at positions corresponding to the separation angle of the diffraction grating 22 on a straight line.

In such a configuration, a transmission / reception operation will be described. First, information to be transmitted is input as an electric signal to an electronic circuit (not shown) that drives the light emitting elements 3a, 3b, or 3c. When the driving current from the electronic circuit is input to the light emitting elements 3a, 3b, or 3c, the light emitting elements 3a, 3b, or 3c emit light as light modulated according to the signal. The emitted transmission light is substantially totally reflected by the corresponding reflecting surface 8 a, 8 b, or 8 c of the truncated pyramid mirror 4 and enters the optical fiber 1. The incident light propagates through the core 1a of the optical fiber 1 and reaches the destination for communication. This is performed for three wavelengths (λ ₁ , λ ₂ , λ ₃ ).

On the other hand, three wavelengths of light λ ₁ , λ ₂ , and λ ₃ emitted from the other end and propagating through the optical fiber 1 are emitted at divergence angles corresponding to the numerical aperture NA of the optical fiber 1 at the end of the optical fiber 1. . These lights are collected by the lens 21 at the upper part of the cavity 9 of the truncated pyramid mirror 4 and enter the diffraction grating 22 through the cavity 9. Since the diffraction angle of the diffraction grating 22 differs depending on the wavelength, the diffraction grating 22 is separated for each wavelength and enters the light receiving element 6a, 6b or 6c. The light receiving element 6a, 6b or 6c converts it into an electric signal in accordance with an incident modulated optical signal (received light), is input to an amplifier circuit (not shown), is amplified, and is input to the processing circuit.

  In this way, bidirectional wavelength division multiplexing optical communication is performed. The multiplexing number is determined by the number of light emitting elements 3 that can be arranged and the separation performance of the diffraction grating 22.

  Therefore, according to the present embodiment, in addition to the effects of the first embodiment, the received light is condensed by the lens 21 and received by the light receiving elements 6a, 6b, 6c, whereby small light receiving elements 6a, 6b. , 6c can be used, so that the communication speed can be increased. In addition, since the layer in which the plurality of light emitting elements 3a, 3b, 3c are arranged and the layer in which the plurality of light receiving elements 6a, 6b, 6c are arranged as separate layers, the lateral direction of the bidirectional optical communication apparatus The spread can be reduced, and thus the apparatus can be reduced in size. In addition, since the diffraction grating 22 is arranged, the wavelength can be divided before the plurality of light receiving elements 6a, 6b, and 6c, and light can be received more efficiently. In addition, by combining the diffraction grating 22 and the lens 21, the size of the light receiving elements 6a, 6b, 6c can be reduced, and high-speed wavelength division multiplexing communication is possible.

In the present embodiment, a triangular frustum is shown as the truncated pyramid-shaped mirror 4 and an example with respect to three wavelengths (λ ₁ , λ ₂ , λ ₃ ) is shown. However, as shown in FIG. (Λ ₁ , λ ₂ , λ ₃ , λ ₄ ) or 6 wavelengths (λ ₁ , λ ₂ , λ ₃ , λ ₄ , λ ₅ , λ ₆ ) as shown in FIG. You can also. Other than this, various multi-wavelengths can be supported.

[Third embodiment]
A third embodiment of the present invention will be described with reference to FIG. The present embodiment relates to the alignment structure of the optical fiber 1 with respect to the configuration example of the first or second embodiment described above. Here, an application example of the first embodiment is shown.

  In the present embodiment, the positioning spacer 31 for arranging the optical fiber 1 at an accurate position with respect to the substrate 2 on which the light emitting elements 3a, 3b, 3c and the truncated pyramid-shaped mirror 4 are mounted is provided with the substrate 2 and the light. It is arranged between the fiber 1. The example shown in FIG. 9 is an example in which the positioning spacers 31 are arranged in the height direction. However, in the case of the lateral arrangement, the positioning spacers 31 may be arranged as shown in FIG.

  Here, the positioning spacer 31 is manufactured by molding or cutting of resin, metal, or glass, or manufactured using a semiconductor manufacturing process using a Si substrate. The positioning spacer 31 is provided with a through hole 32 for determining the position of the optical fiber 1. A positioning mark 33 for determining the position with respect to the substrate 2 is provided. The positioning mark 34 is also provided on the substrate 2. Since the positions are aligned based on these positioning marks 33 and 34, the marks are easily aligned. Specifically, a mark used in a semiconductor manufacturing process or the like may be used. In the case of an opaque material such as metal, the outer shape of the positioning spacer 31 itself and the positioning mark 34 on the substrate 2 may be matched. When aligning, the position can be aligned with high accuracy by using a dedicated device such as an aligner. When a Si substrate is used, infrared light is transmitted, so that alignment can be performed using infrared light. Fix after alignment. An adhesive or the like is used for fixing.

  The optical fiber 1 is positioned by aligning the outer shape of the optical fiber 1 with the through hole 32 of the alignment spacer 31. After positioning, fix with adhesive.

  According to the present embodiment, by providing the positioning structure, it is possible to easily align the optical fiber 1 and the truncated pyramid mirror 4 and to reduce the manufacturing cost of the entire apparatus.

[Fourth embodiment]
A fourth embodiment of the present invention will be described with reference to FIG. The bidirectional optical communication apparatus of the present embodiment is an application example to a configuration example according to the second embodiment, in which the wavelength of the light emitting element 3 is 1.3 μm or more.

  In the present embodiment, a monolithic hologram 41 having both the functions of the lens 21 and the diffraction grating 22 described above is provided on the top of the cavity 9 of the truncated pyramid mirror 4. That is, the hologram 41 has not only a function of a diffraction grating that changes a diffraction angle depending on a wavelength but also a lens function. Further, the truncated pyramidal mirror 4 and the hologram 41 are made of Si constituting the substrate 2. However, a reflecting film (for example, aluminum) is deposited on the reflecting surfaces 8a, 8b, and 8c of the truncated pyramid mirror 4. On the Si substrate 2, light emitting elements 3a, 3b, 3c are mounted and arranged via submounts 7a, 7b, 7c. The light emission wavelengths of the light emitting elements 3a, 3b, 3c are 1.3 μm or more, and the Si material is transmitted in this wavelength region. Accordingly, the light is reflected by the reflecting surfaces 8a, 8b, and 8c on the surface of the truncated pyramid mirror 4, and is transmitted and diffracted by the hologram 41 portion.

  In order to produce the truncated pyramid mirror 4 on such a Si substrate 2, a semiconductor process using photolithography and etching may be used. That is, the photosensitive material is patterned into a truncated pyramid shape, and the shape is directly transferred by dry etching, or is produced by utilizing the anisotropy of Si by wet etching. Similarly, the hologram 41 is patterned by transferring a photosensitive material and etching the shape as it is, or by etching a metal film for patterning the photosensitive material and removing the photosensitive material and then using the metal film as a mask (lift-off). Can be produced.

  In the present embodiment, the hologram 41 has a light condensing function (lens function). However, the light converging function may be provided in another lens to form a hologram having only a diffraction grating function. In this case, a convex Si lens may be fabricated on the top of the truncated pyramid mirror 4 and a diffraction grating may be fabricated on the back side of the substrate 2.

  According to the present embodiment, since the optical element having a wavelength selectivity and the lens are integrally configured as the hologram 41, these components can be combined into one, and the apparatus can be miniaturized. Further, by using a material that is basically transparent to the wavelength used except for the reflecting surfaces 8a, 8b, and 8c, the pyramid-shaped mirror 4 and the lens or the optical element having wavelength selectivity on one substrate 2 is a semiconductor. It is possible to manufacture integrally using a manufacturing process, and it is possible to provide a large amount of highly accurate products at low cost.

It is sectional drawing which shows a part of structure of the bidirectional | two-way optical communication apparatus of 1st embodiment of this invention. It is the one part top view. It is a schematic perspective view which shows the example of a shape of each reflective surface of a truncated pyramid shaped mirror. It is sectional drawing which shows a part of structure of the bidirectional | two-way optical communication apparatus of 2nd embodiment of this invention. It is the one part top view. It is a top view which shows the arrangement | positioning relationship between a diffraction grating and a light receiving element. It is a top view which shows the modification of a truncated pyramid shaped mirror. It is a top view which shows another modification of a truncated pyramid shaped mirror. It is a disassembled perspective view which shows 3rd embodiment of this invention. It is a disassembled perspective view which shows the modification. It is a schematic perspective view which shows 4th embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Substrate 3 Light emitting element 4 Pyramidal trapezoidal mirror 6 Light receiving element 8 Reflecting surface 9 Cavity part 10, 11 Mark 21 Lens 22 Optical element 31 Positioning structure 41 Hologram

Claims (13)

In a bidirectional optical communication device that transmits and receives with one optical fiber,
A plurality of light emitting elements;
A light receiving element;
A truncated pyramid-shaped mirror having a plurality of reflecting surfaces for substantially totally reflecting the transmission light emitted from the light emitting element and coupling it to the optical fiber, and a cavity for guiding the reception light emitted from the optical fiber to the light receiving element When,
A bidirectional optical communication apparatus comprising: The hollow portion opens at an angle larger than the radiation angle of the optical fiber,
The bidirectional optical communication device according to claim 1. The light emitting element is arranged such that the transmitted light emitted is substantially totally reflected by the corresponding reflecting surface of the truncated pyramid mirror and enters the optical fiber.
The bidirectional optical communication apparatus according to claim 1 or 2, wherein The truncated pyramid mirror and the light emitting element are disposed on the same layer,
The light receiving element is disposed on another layer;
The bidirectional optical communication apparatus according to claim 3. A lens that is disposed in the cavity of the truncated pyramid mirror and collects the received light emitted from the optical fiber on the light receiving element;
5. The bidirectional optical communication apparatus according to claim 1, wherein The plurality of light emitting elements each emit transmission light having different wavelengths.
The bidirectional optical communication device according to claim 1. The truncated pyramid mirror and the plurality of light emitting elements are disposed on the same layer,
A plurality of the light receiving elements are disposed on another layer,
The bidirectional optical communication apparatus according to claim 6. An optical element having wavelength selectivity is provided in the front stage on the incident side of the plurality of light receiving elements,
The bidirectional optical communication apparatus according to claim 7. A lens that is disposed in the cavity of the truncated pyramid mirror and collects the received light emitted from the optical fiber on the light receiving element;
An optical element having wavelength selectivity disposed between the lens and the plurality of light receiving elements;
The bidirectional optical communication apparatus according to claim 7, further comprising:   The bidirectional optical communication apparatus according to claim 9, wherein the lens and the optical element are integrally formed by a hologram.   The bidirectional optical communication device according to any one of claims 1 to 10, further comprising an alignment structure for aligning a positional relationship between the optical fiber and the truncated pyramid mirror.   While the reflecting surface has a high reflectivity with respect to the wavelength of the transmitted light emitted by the light emitting element, the truncated pyramid mirror itself, the lens, or the optical element having wavelength selectivity is all the wavelength of the received light. The bidirectional optical communication apparatus according to claim 1, wherein the bidirectional optical communication apparatus is transparent. 13. A mark for positioning the truncated pyramid-shaped mirror and the light-emitting element is provided on a substrate on which the truncated pyramid-shaped mirror and the light-emitting element are disposed. Two-way optical communication device.

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