JP2009134157A - Optical transmission assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical transmission assembly that reduces electric crosstalk. <P>SOLUTION: In the optical transmission assembly, a light emitting device 4 and a light receiving device 5 are mounted on the same substrate 6. The substrate 6 includes a flexible part 6a between the mounting places of the light emitting device 4 and the light receiving device 5, wherein the flexible part 6a is bent, so that the light receiving device 5 faces the incident light transmitting side of a wavelength filter 3 and that the light emitting device 4 faces the wavelength filter 3 from a direction intersecting the incident light. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical transmission assembly that reduces electrical crosstalk.

  An optical transceiver has a light emitting element and a light receiving element built in a predetermined housing whose shape and dimensions are defined, and has peripheral circuits such as a bias, a preamplifier, and a driver, and converts electrical communication signals from host devices into optical communication signals. The optical communication signal from the outside is converted into an electric communication signal and taken into the host device. A light guide for guiding an optical communication signal with the outside is an optical waveguide, an optical fiber, or the like.

  In some optical transceivers, in order to share the light guides of the emitted light and the incident light, the wavelengths of the emitted light and the incident light are made different from each other and are demultiplexed by a wavelength filter placed inside. For example, as shown in FIG. 6, the light transmission assembly 61 described in Patent Document 1 includes a light emitting element array 64 and a light receiving element array 65 mounted on a substrate 66 placed in parallel with the light guide 62. Both the emission direction of the array 64 and the incident direction of the light receiving element array 65 are perpendicular to the mounting surface of the substrate 66. The substrate 66 is assembled in an optical transceiver housing (not shown), a wavelength filter 63a having a reflection wavelength λ2 is disposed above the light emitting element array 64, and a wavelength filter 63b having a reflection wavelength λ1 is disposed above the light receiving element array 65. To do.

  In the optical transmission assembly 61, the light emitted from the light emitting element array 64 having the wavelength λ2 is reflected by the wavelength filter 63a and emitted to the light guide 62. The incident light of wavelength λ1 from the light guide 62 is transmitted through the wavelength filter 63a, reflected by the wavelength filter 63b, and incident on the light receiving element array 65.

  As described above, conventionally, when the emitted light and the incident light having different wavelengths are guided by the common light guide 62, the light emitting element and the light receiving element are arranged on the substrate 66 parallel to the light guide 62 at different distances in the extending direction of the light guide 62. The wavelength filters 63 a and 63 b having the respective wavelengths as reflection wavelengths are arranged at positions where the outgoing optical axis and the incident optical axis intersect with the extension axis of the light guide 62.

JP-T-2002-534709

  The light emitting element consumes a large amount of power to obtain a large light energy of emitted light, and a large current flows from the driver to the light emitting element. On the other hand, the light receiving element generates a weak current from incident light and amplifies this current in the preamplifier. Therefore, it is not desirable that the light emitting element and the light receiving element are arranged close to each other as in the prior art because radiation due to the driving current of the light emitting element affects the light receiving current of the light receiving element.

  However, in the optical transmission assembly of FIG. 6, several problems occur when the distance between the light emitting element and the light receiving element is longer than the conventional one.

  Although the influence of radiation can be reduced by increasing the distance between the light receiving element and the light emitting element, it is necessary to increase the length of the substrate. On the other hand, the length of the housing is defined in the standard, and the housing cannot be lengthened. Therefore, the improvement measure of extending the distance between the light emitting element and the light receiving element by extending the length of the substrate makes it difficult to incorporate the optical transmission assembly into the housing.

  In addition, since the lenses are provided between the light guide and the wavelength filter, and between the light emitting element and the light receiving element, the light is collimated between the wavelength filters. However, even if the lens is collimated, the diffusion angle does not become zero at all, so that the diffusion width increases as the optical path length increases. Therefore, when the distance between the light receiving element and the light emitting element is increased, the optical path length between the wavelength filters is increased, and the diffusion width is increased accordingly. In order to prevent this, it is not preferable to add a lens in the middle, resulting in an increase in parts and a complicated structure.

  As described above, the conventional optical transmission assembly does not find a suitable improvement measure even if it is desired to improve that the radiation due to the driving current of the light emitting element affects the light receiving current of the light receiving element (electrical crosstalk). Is the current situation.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical transmission assembly that solves the above problems and reduces electrical crosstalk.

  To achieve the above object, the present invention provides a light emitting element that emits an optical signal having a wavelength λ2, a light receiving element that receives an optical signal having a wavelength λ1 different from the wavelength λ2, an emitted light having the wavelength λ2, and the wavelength. a light guide for transmitting the incident light of λ1, and a wavelength filter for separating the emitted light of the wavelength λ2 and the incident light of the wavelength λ1, and facing the wavelength filter at a predetermined inclination angle with respect to the light guide. By this, the incident light from the light guide passes through the wavelength filter and travels straight, and the light emitted from the light emitting element entering the wavelength filter from the direction intersecting the incident light is reflected to the light guide. In the transmission assembly, the light emitting element and the light receiving element are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the light emitting element and the light receiving element, and the flexible portion is bent. And above Light-receiving element faces the incoming light transmitting side of the wavelength filter, in which the light emitting element faces the said wavelength filter from the direction intersecting the incident light.

  The wavelength filter is accommodated in an optical block transparent to both wavelengths λ1 and λ2, and the optical block includes an incident lens on a surface facing the light receiving element, an output lens on a surface facing the light emitting element, An entrance / exit lens may be formed on the surface facing the light guide.

  An electrical connector may be mounted on the opposite surface of the substrate where the light receiving element is mounted.

  The present invention also includes a light emitting element that emits an optical signal having a wavelength λ2, a light receiving element that receives an optical signal having a wavelength λ1 different from the wavelength λ2, an emitted light having the wavelength λ2, and an incident light having the wavelength λ1. And a wavelength filter that separates the emitted light having the wavelength λ2 and the incident light having the wavelength λ1, and by facing the wavelength filter at a predetermined inclination angle with respect to the light guide, Incident light from the light guide is reflected by the wavelength filter in a direction intersecting with the incident light, and emitted light from the light emitting element entering the wavelength filter from an extension direction of the incident light passes through the wavelength filter and travels straight. In the optical transmission assembly that is incident on the light guide, the light emitting element and the light receiving element are mounted on the same substrate, and the substrate has a flexible portion between the mounting positions of the light emitting element and the light receiving element. The flexible portion is bent, the light emitting element faces the incident optical extension side of the wavelength filter, in which the light receiving element faces the said wavelength filter from the direction intersecting the incident light.

  The substrate may be a flexible portion from the mounting position of the light emitting element to the mounting position of the light receiving element, and may be bent from the mounting position of the light emitting element to the mounting position of the light receiving element.

  The present invention also includes a light receiving element that receives an optical signal having a wavelength λ2, a light receiving element that receives an optical signal having a wavelength λ1 different from the wavelength λ2, an incident light having the wavelength λ2, and an incident light having the wavelength λ1. And a wavelength filter that separates the incident light having the wavelength λ2 and the incident light having the wavelength λ1, and facing the wavelength filter at a predetermined inclination angle with respect to the light guide. In the optical transmission assembly in which one incident light from the light guide is reflected by the wavelength filter in a direction intersecting with the incident light, and the other incident light passes through the wavelength filter and travels straight, the two light receiving elements are placed on the same substrate. Mounted, the substrate has a flexible portion between the mounting locations of the two light receiving elements, the flexible portion is bent, and one light receiving element faces the incident light transmitting side of the wavelength filter, The other light receiving element There are those faces from a direction intersecting with the incident light to the wavelength filter.

  Further, the present invention provides a light emitting element that emits an optical signal having a wavelength λ2, a light emitting element that emits an optical signal having a wavelength λ1 different from the wavelength λ2, an emitted light having the wavelength λ2, and an emitted light having the wavelength λ1. And a wavelength filter that separates the emitted light having the wavelength λ2 and the emitted light having the wavelength λ1, and by facing the wavelength filter at a predetermined inclination angle with respect to the light guide, In the optical transmission assembly in which the emitted light of the second light passes through the wavelength filter and travels straight and enters the light guide, and the other emitted light that enters the wavelength filter from the direction intersecting the emitted light is reflected to the light guide. Two light emitting elements are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the two light emitting elements, the flexible portion is bent, and one light emitting element is the wavelength filter Of the above light Id and faces the opposite side, the other light emitting element is what faces the said wavelength filter from the direction intersecting the light emitted into the light guide.

  The present invention also provides a light receiving element that receives an optical signal, a light receiving element that receives an optical signal having a polarization angle different from that of the optical signal, a light guide that transmits incident light of the two optical signals, and the 2 A polarization separation element that separates incident light of one optical signal according to a polarization angle, and by facing the polarization separation surface of the polarization separation element at a predetermined inclination angle with respect to the light guide, Optical transmission in which incident light of an optical signal having one polarization angle is reflected by the polarization separation element in a direction intersecting the incident light, and incident light of an optical signal having the other polarization angle is transmitted through the polarization separation element and travels straight. In the assembly, the two light receiving elements are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the two light receiving elements, and the flexible portion is bent, so that one of the light receiving elements Is the incident light transmission side of the polarization separation element Faces, in which the other light receiving element faces the direction intersecting the incident light on the polarization separation element.

  The present invention exhibits the following excellent effects.

  (1) Electrical crosstalk can be reduced.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, an optical transmission assembly 1 according to the present invention includes a wavelength filter 3 at a predetermined inclination angle with respect to a light guide 2 that guides outgoing light of wavelength λ2 and incident light of wavelength λ1 in opposite directions. , The incident light from the light guide 2 passes through the wavelength filter 3 and travels straight, and the emitted light entering the wavelength filter 3 is reflected to the light guide 2 from the direction intersecting the incident light.

  In the optical transmission assembly 1 of the present invention, a light emitting element 4 that emits outgoing light and a light receiving element 5 that receives incident light are mounted on the same substrate 6, and the substrate 6 is between the mounting positions of the light emitting element 4 and the light receiving element 5. It has a flexible portion 6a, the flexible portion 6a is bent, the light receiving element 5 faces the incident light transmitting side of the wavelength filter 3, and the light emitting element 4 faces the wavelength filter 3 from the direction intersecting the incident light. It is what.

  Here, the light guide 2 is an optical waveguide or an optical fiber.

  The wavelength filter 3 transmits incident light having a wavelength λ1 that enters from the light guide 2 and reflects outgoing light having a wavelength λ2 that enters from the light emitting element 4 to the light guide 2.

  The light emitting element 4 emits emitted light having a wavelength λ2, and is, for example, an LD (laser diode). A peripheral circuit 7 such as a driver is mounted in the vicinity of the light emitting element 4. The light emitting element 4 may be one or plural. The plurality of light emitting elements 4 may be arranged in an array in a direction perpendicular to the paper surface.

  The light receiving element 5 receives incident light having a wavelength λ1, and is, for example, a PD (photodiode). A peripheral circuit 8 such as a bias and a preamplifier is mounted in the vicinity of the light receiving element 5. The light receiving element 5 may be one or plural. The plurality of light receiving elements 5 are preferably arranged in an array in a direction perpendicular to the paper surface.

  The substrate 6 has a flexible portion 6a made of a flexible substrate, a light emitting element mounting portion 6b made of a rigid substrate, and a light receiving element mounting portion 6c made of a rigid substrate. Note that both rigid substrates may be multilayer substrates, one of which may be a flexible substrate, and the flexible substrate may be integrally connected by the light emitting element mounting portion 6b, the flexible portion 6a, and the light receiving element mounting portion 6c.

  The rigid substrate is made of a hard material such as glass epoxy, and the flexible substrate is a printed substrate using a polyimide material or the like as a material that bends due to incorporation or repeated bending. The flexible substrate and the rigid substrate are electrically connected by a through hole.

  The light guide 2 and the wavelength filter 3 are arranged in parallel to the light emitting element mounting portion 6 b of the substrate 6, and the light receiving element 5 is located on the extension of the optical axis of the light guide 2. The flexible substrate constituting the flexible portion 6a is bent so that the light receiving element mounting portion 6c is perpendicular to the light emitting element mounting portion 6b. In addition, although not shown, a collimating lens is disposed between the wavelength filter 3 and the light receiving element 5, between the wavelength filter 3 and the light emitting element 4, and between the wavelength filter 3 and the light guide 2. It is preferable to reduce the loss.

  The light emitting element mounting portion 6b and the light receiving element mounting portion 6c are housed and fixed in a housing (not shown) to maintain the positional relationship shown in FIG.

  As shown in FIG. 2, the peripheral circuit 8, the light receiving element 5, the light emitting element 4, and the peripheral circuit 7 are mounted on the substrate 6 with the substrate 6 being straight. At this time, the light receiving element 5 is further away from the light emitting element 4 than the conventional one (FIG. 6) by the flexible portion 6a.

  The straight substrate 6 on which the components are mounted in this manner is aligned with the wavelength filter 3 and fixed to a housing (not shown). The alignment is performed such that light emitted from the light emitting element 4 of the light emitting element mounting portion 6b is reflected by the wavelength filter 3 and is most appropriately incident on the optical axis of the light guide 2. Thereafter, the flexible portion 6a is bent, and the light receiving element mounting portion 6c is erected so as to be perpendicular to the light emitting element mounting portion 6b, resulting in the state shown in FIG.

  The operation in the optical transmission assembly 1 of FIG. 1 will be described.

  First, when incident light having a wavelength λ 1 from the light guide 2 enters the wavelength filter 3, the incident light passes through the wavelength filter 3 and travels straight and enters the light receiving element 5.

  Here, the wavelength filter 3 is disposed with an inclination of 45 degrees with respect to the optical axis of the light guide 2.

  On the other hand, the emitted light having the wavelength λ 2 emitted from the light emitting element 4 is reflected by 90 ° by the wavelength filter 3 and enters the light guide 2. As described above, the optical transmission assembly 1 enables optical transmission in which the light guides of the emitted light and the incident light are shared.

  The effect of the optical transmission assembly 1 of FIG. 1 will be described.

  In the optical transmission assembly 1 of the present invention, the flexible portion 6a is bent so that the light receiving element 5 faces the incident light transmitting side of the wavelength filter 3, and the light emitting element 4 faces the wavelength filter 3 from the direction intersecting the incident light. Yes. As described above, since the light receiving element 5 and the light emitting element 4 are not arranged on the same plane, the distance between the light receiving element 5 and the light emitting element 4 is longer than before, and radiation by the driving current of the light emitting element affects the light receiving current of the light receiving element. The electrical crosstalk that gives

  In addition, the light receiving element mounting portion 6c of the substrate 6 is positioned in the vicinity of the wavelength filter 3 by bending the flexible portion 6a. Therefore, the optical path length of the light collimated by the lens is not increased, and it is not necessary to add a lens in the middle.

  Here, considering the mounting accuracy of the optical transmission assembly, when the light guide 2 is a multimode optical fiber, the core has a diameter of about 50 μm, and therefore the mounting accuracy of the light emitting element 4 may be several μm. . However, when the light guide 2 is a single mode optical fiber, the core has a diameter of about 10 μm. Therefore, the mounting accuracy of the light emitting element 4 is required to be less than 1 μm. On the other hand, since the light receiving surface of the light receiving element 5 has a diameter of about 50 μm, the mounting accuracy with respect to the optical axis of the light guide 2 may be several μm.

  Therefore, in the optical transmission assembly 1 of the present invention, the light receiving element 5 whose positioning accuracy is roughly larger than that of the light emitting element 4 is arranged at the tip of the flexible portion 6a. For this reason, after aligning the light emitting element 4, it is possible to simply bring the light receiving element 5 to a position where sufficient light can be received simply by bending the flexible part 6a and raising the light receiving element mounting part 6c. it can.

  Next, a modification of this embodiment will be described.

  As shown in FIG. 3, in the same manner as the optical transmission assembly 1, the optical transmission assembly 31 according to the present invention has a light emitting element 4 that emits emitted light and a light receiving element 5 that receives incident light mounted on the same substrate 36. The substrate 36 has a flexible portion 36a between the mounting positions of the light emitting element 4 and the light receiving element 5, and the flexible portion 36a is bent so that the light receiving element 5 faces the incident light transmitting side of the wavelength filter 3. The light emitting element 4 faces the wavelength filter 3 from the direction intersecting the incident light.

  The difference from the optical transmission assembly 1 is that the substrate 36 is composed not only of the flexible portion 36a but also of the light emitting element mounting portion 6b and the light receiving element mounting portion 6c only of a flexible substrate, and a rigid substrate is not used. is there. Only the flexible portion 36a is bent as shown, and the light emitting element mounting portion 6b and the light receiving element mounting portion 6c are not bent. Therefore, the positional relationship among the wavelength filter 3, the light emitting element 4, and the light receiving element 5 is the same as that of the optical transmission assembly 1.

  The substrate 36 made entirely of a flexible substrate may be fixed to the housing by attaching fixing members 37b, 37c made of a metal plate or the like to a part of the substrate 36 and YAG laser welding or screwing the fixing members to the housing. .

  Also in the optical transmission assembly 31 which is a modified example, similarly to the optical transmission assembly 1, there is an effect that the influence of the radiation due to the driving current of the light emitting element 4 on the light receiving current of the light receiving element 5 can be reduced.

  In addition to this, the optical transmission assembly 31 has the advantage that the optical transmission assembly 31 can be manufactured at low cost because the substrate 36 is formed of only a flexible substrate without using a rigid substrate.

  In the optical transmission assembly 1 of FIG. 1 (the same applies to the optical transmission assembly 31 of FIG. 3), the light-emitting element 4 and the light-receiving element 5 are mounted on the substrate 6, and the flexible portion 6a of the substrate 6 is bent and placed ahead of it. By raising the light receiving element mounting portion 6c, the light receiving element 5 and the light emitting element 4 are faced to different surfaces of the wavelength filter 3, but when the light guide 2 is a multimode optical fiber, the mounting accuracy of the above-described optical transmission assembly In consideration of the above, since the core diameter is about 50 μm, the mounting accuracy of the light emitting element 4 may be several μm. Therefore, the light emitting element 4 is mounted on the tip of the substrate 6 and the light receiving element 5 is incident from the light guide 2. You may make it approach the wavelength filter 3 from the direction which crosses light. When the flexible portion 6a is bent, the light emitting element 4 faces the incident light transmitting side of the wavelength filter 3, so that the wavelength filter 3 transmits the emitted light having the wavelength λ2 and reflects the incident light having the wavelength λ1. Use what you want.

  Further, instead of mounting the light receiving element 5 and the light emitting element 4 on the substrate 6, the light receiving elements 5 may be mounted at two places. That is, the light receiving element 5 for receiving the incident light having the wavelength λ1 and the light receiving element 5 for receiving the incident light having the wavelength λ2 are mounted. As a result, when the wavelength-multiplexed incident light enters the wavelength filter 3 from the light guide 2, the wavelength-separated light is incident on and received by the two light receiving elements 5. An optical transmission assembly can be realized.

  Here, instead of the wavelength filter 3, a polarization separation element that is an optical component having a function of separating a light beam according to polarization, such as a polarization beam splitter, may be used. By providing a polarization beam splitter as the polarization separation element, an optical signal can be separated and detected according to the polarization state. The polarization beam splitting surface of the polarizing beam splitter is tilted by 45 ° with respect to the optical axis of the light guide 2 to detect the two polarized light in a state where the optical path is separated by approximately 90 ° (the same structure as in FIGS. 1, 3 and 4). it can. For example, the magneto-optical disk is irradiated with a laser beam and the signal reflected by the magneto-optical disk is separated into an S-polarized component and a P-polarized component (polarized light orthogonal to the S-polarized component) and detected. It can be used to read a signal written on a disc. At this time, the structure is the same as the conventional structure using a lens coupling system as the light guide 2, and the mounting becomes easy.

  On the other hand, the light emitting element 4 may be mounted at two places on the contrary. That is, the light emitting element 4 that emits the emitted light having the wavelength λ1 and the light emitting element 4 that emits the emitted light having the wavelength λ2 are mounted. Thereby, since the emitted light wavelength-multiplexed by the wavelength filter 3 is emitted from the light guide 2, an optical transmission assembly for wavelength-multiplexed light transmission can be realized.

  As an example, the optical transmission assembly for wavelength-multiplexed optical transmission can be used as a light source module for a laser printer. By further wavelength-multiplexing the arrayed LDs, it is possible to print with a larger number of optical signals, which facilitates high-speed printing.

  Next, another embodiment of the present invention will be described.

  As shown in FIG. 4, the optical transmission assembly 41 according to the present invention has a wavelength filter 3 with a predetermined inclination angle with respect to the light guide 2 that guides the outgoing light of wavelength λ2 and the incoming light of wavelength λ1 in opposite directions. The incident light from the light guide 2 passes through the wavelength filter 3 and travels straight, so that the emitted light entering the wavelength filter 3 is reflected to the light guide 2 from the direction intersecting the incident light. In the optical transmission assembly 1 of the optical transceiver, the light emitting element 4 that emits the emitted light and the light receiving element 5 that receives the incident light are mounted on the same substrate 6, and the substrate 6 is disposed between the mounting positions of the light emitting element 4 and the light receiving element 5. It has a flexible portion 6a, the flexible portion 6a is bent, the light receiving element 5 faces the incident light transmitting side of the wavelength filter 3, and the light emitting element 4 faces the wavelength filter 3 from the direction intersecting the incident light. It is what.

  The difference from the optical transmission assembly 1 is that the wavelength filter 3 is accommodated in an optical block 43 transparent to both wavelengths λ1 and λ2, and the optical block 43 has an incident lens 43a on the surface facing the light receiving element 5, The exit lens 43b is formed on the surface facing the light emitting element 4, and the entrance / exit lens 43c is formed on the surface facing the light guide 2.

  The optical block 43 is provided with a hole (groove) for accommodating the wavelength filter 3, and a slope inclined at a predetermined angle with respect to the optical axis of the light guide 2 is formed in the hole. By placing the wavelength filter 3 on this slope, the position and posture of the wavelength filter 3 with respect to the optical axis can be determined. The hole containing the wavelength filter 3 is preferably filled with a transparent filler (refractive index matching material) (not shown). Thereby, the wavelength filter 3 can be made hard to receive the influence from the water | moisture content of external air (air).

  The light transmission assembly 41 of this embodiment also has an effect that the influence of the radiation due to the drive current of the light emitting element 4 on the light reception current of the light receiving element 5 can be reduced as in the case of the light transmission assembly 1.

  In addition, since each lens is integrally formed in the optical block 43, the number of parts is reduced and the alignment of the wavelength filter 3 and each lens is simplified. Since the shape of the optical block 43 itself is simple, the manufacturing is facilitated.

  Furthermore, in this embodiment, the optical block 43 is formed with a fitting portion 43d for fitting the light guide 2 together. The fitting portion 43d is a hole having the same shape as the outer shape of the light guide 2, and an entrance / exit lens 43c is formed at a position corresponding to the optical axis of the light guide 2 in the fitting portion 43d. Thereby, alignment is achieved only by fitting the light guide 2 to the fitting portion 43d.

  As a result, the alignment of the optical block 43 and the light guide 2 is simplified, and the optical block 43 and the light guide 2 can be handled as a single component in which they are integrated.

  As shown in FIG. 5, the optical transmission assembly 51 according to the present invention has an electrical connector on the opposite surface 6d of the light receiving element mounting portion 6c on which the light receiving element 5 of the substrate 6 is mounted in the optical transmission assembly 41 described above. 9 is implemented.

  In this embodiment, the optical transmission assembly 51 is accommodated in the housing 10 of the optical transceiver. The light receiving element mounting portion 6 c and the electrical connector 9 are fixed to the housing 10. Here, the housing 10 has a simplified side profile and a rectangular cross-sectional profile. The light receiving element mounting portion 6 c is located within one end surface of the housing 10, and the electrical connector 9 appears outside the housing 10.

  The electrical connector 9 connects the optical transceiver and the outside (specifically, the peripheral circuits 7 and 8 of the optical transmission assembly 51 and the interface circuit of the host device are electrically connected). The electrical connector 9 is at a position facing the light guide 2, and the light guide 2 is directly or indirectly connected to the counterpart optical communication device, and the electrical connector 9 is connected to the host device.

  At this time, since the electrical connector 9 is mounted on the opposite surface 6d of the light receiving element mounting portion 6c, the electrical connector 9 can be taken out of one end surface of the housing 10. Since the electrical connector 9 is outside the one end surface of the housing 10, it becomes easy to insert / remove the optical transceiver to / from the host device.

  In the present embodiment, a laser diode is used as the light emitting element 4. However, when a VCSEL-LD (vertical cavity surface emitting laser) that is a surface mount type is used, the optical coupling is perpendicular to the mounting surface. This is preferable because mounting becomes easy. When VCSEL-LD is used, the emission wavelength is in the 850 nm band.

  On the other hand, an edge-emitting FB-LD (Fabry-Perot laser), DFB-LD (Distributed Feedback laser), or the like may be used. In the case of using an edge-emitting LD such as FB-LD or DFB-LD, it is necessary to mount the light emitting element on the submount and make the emission direction coincide with the incident optical axis of the wavelength filter 3. When FB-LD, DFB-LD, or the like is used, an emission wavelength of 1300 nm band or 1550 nm band can be used, which is convenient for long-distance optical transmission.

  Moreover, although the optical fiber, the optical waveguide, etc. were demonstrated as embodiment as the light guide 2, lens system coupling | bonding may be sufficient.

1 is a side cross-sectional view of an optical transmission assembly showing an embodiment of the present invention. FIG. 2 is a side sectional view of the optical transmission assembly of FIG. 1 during manufacture. FIG. 9 is a side cross-sectional view showing a modification of the optical transmission assembly of FIG. 1. It is a sectional side view of the optical transmission assembly which shows other embodiment of this invention. It is a sectional side view of the optical transmission assembly which shows other embodiment of this invention. It is a perspective view of the conventional optical transmission assembly.

Explanation of symbols

1, 31, 41, 51 Light transmission assembly 2 Light guide 3 Wavelength filter 4 Light emitting element 5 Light receiving element 6 Substrate 6a Flexible portion 6b Light emitting element mounting portion 6c Light receiving element mounting portion 7, 8 Peripheral circuit 9 Electrical connector 10 Housing 43 Optical block 43a Incident lens 43b Outgoing lens 43c Incoming / outgoing lens

Claims (8)

A light emitting element that emits an optical signal having a wavelength λ2, a light receiving element that receives an optical signal having a wavelength λ1 different from the wavelength λ2, and a light guide that transmits the emitted light having the wavelength λ2 and the incident light having the wavelength λ1. A wavelength filter that separates the emitted light having the wavelength λ2 and the incident light having the wavelength λ1, and the incident light from the light guide by facing the wavelength guide at a predetermined inclination angle with respect to the light guide. In the optical transmission assembly in which the light emitted from the light emitting element entering the wavelength filter from the direction intersecting with the incident light is reflected to the light guide from the direction intersecting with the incident light.
The light-emitting element and the light-receiving element are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the light-emitting element and the light-receiving element, and the flexible portion is bent to receive the light-receiving element. An optical transmission assembly, wherein an element faces the incident light transmitting side of the wavelength filter, and the light emitting element faces the wavelength filter from a direction intersecting the incident light.   The wavelength filter is accommodated in an optical block transparent to both wavelengths λ1 and λ2, and the optical block includes an incident lens on a surface facing the light receiving element, an output lens on a surface facing the light emitting element, 2. An optical transmission assembly according to claim 1, wherein an entrance / exit lens is formed on a surface facing the light guide.   The optical transmission assembly according to claim 2, wherein an electrical connector is mounted on the opposite surface of the substrate on which the light receiving element is mounted. A light emitting element that emits an optical signal having a wavelength λ2, a light receiving element that receives an optical signal having a wavelength λ1 different from the wavelength λ2, and a light guide that transmits the emitted light having the wavelength λ2 and the incident light having the wavelength λ1. A wavelength filter that separates the emitted light having the wavelength λ2 and the incident light having the wavelength λ1, and the incident light from the light guide by facing the wavelength guide at a predetermined inclination angle with respect to the light guide. Is reflected in the direction intersecting with the incident light by the wavelength filter, and the light emitted from the light emitting element entering the wavelength filter from the extension direction of the incident light passes through the wavelength filter and travels straight and is incident on the light guide. In the optical transmission assembly
The light emitting element and the light receiving element are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the light emitting element and the light receiving element, the flexible portion is bent, and the light emission An optical transmission assembly characterized in that an element faces the incident light extension side of the wavelength filter, and the light receiving element faces the wavelength filter from a direction intersecting the incident light.   The substrate is a flexible portion from the mounting position of the light emitting element to the mounting position of the light receiving element, and is bent between the mounting position of the light emitting element and the mounting position of the light receiving element. The optical transmission assembly of claim 1. A light receiving element that receives an optical signal having a wavelength λ2, a light receiving element that receives an optical signal having a wavelength λ1 different from the wavelength λ2, and a light guide that transmits incident light having the wavelength λ2 and incident light having the wavelength λ1. A wavelength filter that separates the incident light of the wavelength λ2 and the incident light of the wavelength λ1, and by facing the wavelength filter at a predetermined inclination angle with respect to the light guide, one of the light guides from the light guide In an optical transmission assembly in which incident light is reflected by the wavelength filter in a direction intersecting with the incident light, and the other incident light passes through the wavelength filter and travels straight.
The two light receiving elements are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the two light receiving elements, the flexible portion is bent, and one of the light receiving elements has the wavelength An optical transmission assembly, wherein the optical transmission assembly faces the incident light transmitting side of the filter, and the other light receiving element faces the wavelength filter from a direction intersecting the incident light. A light emitting element that emits an optical signal having a wavelength λ2, a light emitting element that emits an optical signal having a wavelength λ1 different from the wavelength λ2, and a light guide that transmits the emitted light having the wavelength λ2 and the emitted light having the wavelength λ1. A wavelength filter that separates the emitted light of the wavelength λ2 and the emitted light of the wavelength λ1, and by facing the wavelength filter at a predetermined inclination angle with respect to the light guide, one of the emitted lights has the wavelength In an optical transmission assembly in which the other outgoing light that enters the wavelength filter from the direction intersecting with the outgoing light and reflected by the light guide is reflected by the light guide through the filter and straightly entering the light guide.
The two light emitting elements are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the two light emitting elements, the flexible portion is bent, and one light emitting element has the wavelength An optical transmission assembly, wherein the light transmission assembly faces the side opposite to the light guide of the filter, and the other light emitting element faces the wavelength filter from a direction intersecting with light emitted to the light guide. A light receiving element that receives an optical signal, a light receiving element that receives an optical signal having a polarization angle different from that of the optical signal, a light guide that transmits incident light of the two optical signals, and incident light of the two optical signals A polarization separation element that separates the light according to the polarization angle, and has one polarization angle from the light guide by facing the polarization separation surface of the polarization separation element at a predetermined inclination angle with respect to the light guide. In an optical transmission assembly in which incident light of an optical signal is reflected by the polarization separation element in a direction intersecting with the incident light, and incident light of an optical signal having the other polarization angle passes through the polarization separation element and travels straight.
The two light receiving elements are mounted on the same substrate, the substrate has a flexible portion between the mounting positions of the two light receiving elements, the flexible portion is bent, and one of the light receiving elements is An optical transmission assembly, wherein the light transmitting assembly faces the incident light transmitting side of the separating element, and the other light receiving element faces the polarization separating element from a direction intersecting the incident light.

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