Optical transceiver module

Abstract

This invention provides an optical transceiver module that can reduce power consumption while keeping the mounting area of ​​the transmitter and receiver simple and minimizing the increase in area. [Solution] The optical transceiver module 1 comprises a multilayer substrate 10, an optical waveguide 30, a transmitter 40, and a receiver 50. The optical waveguide 30 penetrates the multilayer substrate 10. The transmitter 40 is provided in the first conductor layer 21 of the multilayer substrate 10 and transmits light. The receiver 50 is provided in the second conductor layer 23 of the multilayer substrate 10 so as to face the optical waveguide 30 and receives the received light. The transmitted light is transmitted from the transmitter 40 and input to the end face 201 of the first optical fiber 200 which faces the transmitter 40 in the stacking direction of the multilayer substrate 10. The received light is output from the end face 301 of the second optical fiber 300 which is arranged alongside the first optical fiber 200 and faces the receiver 50 via the optical waveguide 30, propagates through the optical waveguide 30 and is received by the receiver 50.

Description

Technical Field

[0001] The present invention relates to an optical transceiver module.

Background Art

[0002] In recent years, with the high-speed and large-capacity development of data communication, data transmission and reception using optical communication have been widely carried out.

[0003] In optical communication, an optical transceiver module having a transmitter that converts an electrical signal into an optical signal and a receiver that converts an optical signal into an electrical signal is used.

[0004] In the optical transceiver module disclosed in Patent Document 1, a transmitter is provided on the upper surface of a substrate, and a receiver is provided on the lower surface of the substrate.

[0005] On the upper surface of the substrate, an optical guide portion is provided along the upper surface. At one end of the optical guide portion, the end face of a single-mode optical fiber is connected. Also, in the middle of the optical guide portion, a multilayer film mirror is provided, and an optical waveguide penetrating the substrate is communicated.

[0006] In such a configuration, the transmitted light transmitted from the transmitter is input to the other end of the optical guide portion, passes through the multilayer film mirror, and is input to the optical fiber. On the other hand, the received light propagating through the optical fiber is input to one end of the optical guide portion, reflected by the multilayer film mirror, enters the optical waveguide, and is received by the receiver.

[0007] As described above, in the optical transceiver module disclosed in Patent Document 1, among the two surfaces of the substrate, a transmitter is provided on one surface side and a receiver is provided on the other surface side. Therefore, with a simple configuration, the mounting areas of the transmitter and the receiver can be reduced.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

[0009] In recent years, surface-emitting lasers, which have low power consumption, have been developed as light sources for transmitters. Transmitters using surface-emitting lasers transmit light perpendicular to the substrate surface.

[0010] However, the optical transceiver module disclosed in Patent Document 1 is configured to transmit light in a direction parallel to the substrate surface, and therefore cannot use a surface-emitting laser as the light source for the transmitter.

[0011] Therefore, in optical transceiver modules, further improvements were desired to reduce power consumption while keeping the mounting area of ​​the transmitter and receiver simple and minimizing the increase in size.

[0012] This invention has been made in view of the problems of the prior art described above. The object of this invention is to provide an optical transceiver module that can reduce power consumption while keeping the mounting area of ​​the transmitter and receiver simple and minimizing the increase in area. [Means for solving the problem]

[0013] An optical transceiver module according to an aspect of the present invention comprises: a substrate; a multilayer substrate having a first surface conductor layer facing one of the two surfaces of the substrate; a second surface conductor layer facing the other of the two surfaces of the substrate; an optical waveguide penetrating the multilayer substrate; a transmitter provided in the first surface conductor layer for transmitting light; and a receiver provided in the second surface conductor layer facing the optical waveguide for receiving light. The transmitted light is transmitted from the transmitter and input to the first end face of a first optical fiber facing the transmitter in the stacking direction of the multilayer substrate. The received light is output from the second end face of a second optical fiber arranged alongside the first optical fiber and facing the receiver via the optical waveguide, propagates through the optical waveguide, and is received by the receiver. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an optical transceiver module that can reduce power consumption while suppressing an increase in the mounting area of ​​the transmitter and receiver with a simple configuration. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a cross-sectional view of the optical transceiver module according to this embodiment. [Figure 2] Figure 2 is a cross-sectional view of an optical transceiver module according to a first modified example of this embodiment. [Figure 3] Figure 3 is a cross-sectional view of an optical transceiver module according to a second modified example of this embodiment. [Figure 4] Figure 4 is a cross-sectional view of an optical transceiver module according to a third modified example of this embodiment. [Figure 5] Figure 5 is a cross-sectional view of the main part of an optical transceiver module according to a fourth modified example of this embodiment. [Figure 6] Figure 6 is a cross-sectional view of the main part of an optical transceiver module according to a fifth modified example of this embodiment. [Figure 7] Figure 7 is a cross-sectional view of the main part of an optical transceiver module according to a sixth modified example of this embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a main part of an optical transceiver module according to a seventh modification of the present embodiment. [Figure 9] FIG. 9 is a cross-sectional view of an optical transceiver module according to a comparative example.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, the optical transceiver module according to the present embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation and may be different from the actual ratios. Also, the same or similar reference numerals are assigned to the same functions and configurations, and the description thereof will be omitted as appropriate.

[0017] The X direction shown in FIGS. 1 to 9 corresponds to the width direction of the optical transceiver module. The Y direction shown in FIGS. 1 to 9 corresponds to the height direction of the optical transceiver module and is orthogonal to the X direction. Also, the +X side and -X side shown in FIGS. 1 to 9 correspond to the left and right sides of the optical transceiver module, respectively. The +Y side and -Y side shown in FIGS. 1 to 9 correspond to the upper and lower sides of the optical transceiver module, respectively.

[0018] [Configuration of Optical Transceiver Module] First, the configuration of the optical transceiver module 1 will be described. FIG. 1 is a cross-sectional view of the optical transceiver module 1. As shown in FIG. 1, the optical transceiver module 1 includes a multilayer substrate 10, an optical waveguide 30, a transmitter 40, a receiver 50, and a connector housing portion 60.

[0019] The multilayer substrate 10 is a printed substrate having a four-layer structure and includes a substrate 11, a first outer substrate 13, a second outer substrate 15, a first conductor layer 21, a second conductor layer 23, a third conductor layer 25, and a fourth conductor layer 27. The stacking direction of the multilayer substrate 10 coincides with the height direction (Y direction) of the optical transceiver module 1. Note that the multilayer substrate 10 is not limited to a printed substrate having a four-layer structure and may be a printed substrate having a multilayer structure. The first conductor layer 21 and the second conductor layer 23 are also referred to as the first surface conductor layer and the second surface conductor layer, respectively.

[0020] The substrate 11, the first outer substrate 13, and the second outer substrate 15 are made of, for example, FR-4 (glass cloth-based epoxy resin). Circuit patterns are formed on the first conductor layer 21, the second conductor layer 23, the third conductor layer 25, and the fourth conductor layer 27 using, for example, copper foil.

[0021] The substrate 11 is a double-sided substrate and constitutes the core of the multilayer substrate 10. A third conductor layer 25 is provided on one of the two sides of the substrate 11 (the +Y side). A fourth conductor layer 27 is provided on the other side of the substrate 11 (the -Y side).

[0022] The first outer substrate 13 is laminated on the third conductor layer 25. The first outer substrate 13 constitutes the prepreg of the multilayer substrate 10. The first conductor layer 21 is provided on one side (+Y side) of the first outer substrate 13. The third conductor layer 25 is in contact with the other side (-Y side) of the first outer substrate 13. In this way, the first outer substrate 13 is positioned between the first conductor layer 21 and the third conductor layer 25, insulating the first conductor layer 21 from the third conductor layer 25 and bonding the first conductor layer 21 to the third conductor layer 25. With this configuration, the first conductor layer 21 faces one side (+Y side) of the substrate 11.

[0023] The second outer substrate 15 is laminated on the fourth conductor layer 27. The second outer substrate 15 constitutes the prepreg of the multilayer substrate 10. The fourth conductor layer 27 is in contact with one side (+Y side) of the second outer substrate 15. The second conductor layer 23 is provided on the other side (-Y side) of the second outer substrate 15. In this way, the second outer substrate 15 is positioned between the second conductor layer 23 and the fourth conductor layer 27, insulating the second conductor layer 23 from the fourth conductor layer 27 and bonding the second conductor layer 23 to the fourth conductor layer 27. With this configuration, the second conductor layer 23 faces the other side (-Y side) of the substrate 11.

[0024] The optical waveguide 30 penetrates the multilayer substrate 10 along the stacking direction (Y direction) of the multilayer substrate 10. The optical waveguide 30 is a through-hole or via in the multilayer substrate 10. The optical waveguide 30 has a first opening 31 in the first conductor layer 21 and a second opening 33 in the second conductor layer 23. Gold plating 35 is applied around the first opening 31 of the optical waveguide 30 in the first conductor layer 21 and on the inner surface of the optical waveguide 30. This increases the reflectivity within the optical waveguide 30 and increases the transmittance of propagating light.

[0025] In Figure 1, the third conductor layer 25 and the fourth conductor layer 27 are connected to the optical waveguide 30, but this is not limited to this. For example, if the third conductor layer 25 forms the ground for the circuit pattern of the first conductor layer 21, it is preferable that the third conductor layer 25 is not connected to the optical waveguide 30. Similarly, if the fourth conductor layer 27 forms the ground for the circuit pattern of the second conductor layer 23, it is preferable that the fourth conductor layer 27 is not connected to the optical waveguide 30. The circuit patterns of the first conductor layer 21 and the second conductor layer 23 are also referred to as the first circuit pattern and the second circuit pattern, respectively.

[0026] By providing a gap between the third conductor layer 25 and the optical waveguide 30, and also between the fourth conductor layer 27 and the optical waveguide 30, it is possible to suppress the occurrence of parasitic capacitance between the photodetector 51 and the ground, which will be described later. If parasitic capacitance occurs between the photodetector 51 and the ground, the frequency response characteristics deteriorate due to the time constant, affecting the signal quality.

[0027] The transmitter 40 is provided on the first conductor layer 21 and is electrically connected to the first conductor layer 21. The transmitter 40 converts electrical signals into optical signals and transmits light upward (+Y side) toward the optical transceiver module 1. The transmitter 40 comprises a light-emitting element 41, a driver IC 43, and bonding wires 45.

[0028] The light-emitting element 41 is composed of, for example, a vertical-cavity surface-emitting laser (VCSEL) and transmits light upward (+Y side) towards the optical transceiver module 1. The driver IC 43 is an integrated circuit that controls the transmission of light from the light-emitting element 41. For example, when the driver IC 43 receives an electrical signal from the first conductor layer 21, it controls the light-emitting element 41 to transmit light having an amount of light corresponding to the magnitude of the voltage (or current) value of the received electrical signal. The bonding wire 45 electrically connects the light-emitting element 41 to the driver IC 43.

[0029] If the light-emitting element 41 is not composed of a directly modulable laser such as a VCSEL, the transmitter 40 may further include an optical modulator that modulates the intensity, phase, etc., of the transmitted light transmitted by the light-emitting element 41.

[0030] The light-emitting element 41 is provided in the first conductor layer 21. The driver IC 43 is provided in the first conductor layer 21 and is electrically connected to the first conductor layer 21. In this embodiment, the light-emitting element 41 is located to the right (-X side) of the first opening 31 of the optical waveguide 30. The driver IC 43 is located to the right (-X side) of the light-emitting element 41. Alternatively, the light-emitting element 41 may be located to the left (+X side) of the first opening 31 of the optical waveguide 30. In this case, the driver IC 43 is located to the left (+X side) of the light-emitting element 41.

[0031] The receiver 50 is provided on the second conductor layer 23 and is electrically connected to the second conductor layer 23. The receiver 50 receives received light from above (+Y side) the optical transceiver module 1 via the optical waveguide 30 and converts the optical signal into an electrical signal. The receiver 50 comprises a photodetector 51, an amplifier IC 53, bonding wires 55, and a focusing lens 57.

[0032] The light-receiving element 51 is composed of, for example, a back-entry photodiode, and receives received light from above (+Y side) of the optical transceiver module 1 via the optical waveguide 30. Note that a photodiode is also called a photodetector.

[0033] The light-receiving element 51, for example, outputs an electrical signal having a voltage value (or current value) corresponding to the amount of light received when it receives light. The amplifier IC 53 is an integrated circuit that amplifies the electrical signal output from the light-receiving element 51. The bonding wire 55 electrically connects the light-receiving element 51 to the amplifier IC 53.

[0034] The light-receiving element 51 is provided in the second aperture 33 of the optical waveguide 30 in the second conductor layer 23. The amplifier IC 53 is provided in the second conductor layer 23 and is electrically connected to the second conductor layer 23. In this embodiment, the amplifier IC 53 is positioned to the right (-X side) of the light-receiving element 51. If the light-emitting element 41 is positioned to the left (+X side) of the first aperture 31 of the optical waveguide 30, the driver IC 43 will be positioned to the left (+X side) of the light-emitting element 41, and consequently, the amplifier IC 53 will also be positioned to the left (+X side) of the light-receiving element 51.

[0035] The focusing lens 57 is provided on the light-receiving surface (back surface) of the light-receiving element 51 and is positioned within the optical waveguide 30 via the second opening 33 of the optical waveguide 30. The focusing lens 57 focuses the received light that enters the optical waveguide 30 from above (+Y side) of the optical transceiver module 1 and propagates through the optical waveguide 30, and receives the received light on the light-receiving surface of the light-receiving element 51.

[0036] In the optical transceiver module 1, the transmitter 40 and receiver 50 are provided on the first conductor layer 21 and the second conductor layer 23, respectively. With this configuration, in a cross-sectional view of the optical transceiver module 1, the transmitter 40 and receiver 50 can be arranged such that a portion of the transmitter 40 overlaps a portion of the receiver 50 in the direction (X direction) perpendicular to the stacking direction (Y direction) of the multilayer substrate 10. This makes it possible to suppress the increase in the mounting area of ​​the transmitter 40 and receiver 50 in the optical transceiver module 1.

[0037] The connector housing 60 is positioned above (on the +Y side of) the multilayer substrate 10, facing the first conductor layer 21 of the multilayer substrate 10. The connector housing 60 houses the optical connector 100, which will be described later.

[0038] [Optical connector configuration] Next, the configuration of the optical connector 100 will be described. The optical connector 100 is housed in the connector housing 60 of the optical transceiver module 1 and connected to the optical transceiver module 1. The optical connector 100 includes a first optical coupling section 110 and a second optical coupling section 120.

[0039] The first optical coupling unit 110 is connected to the first optical fiber 200. With the optical connector 100 connected to the optical transceiver module 1, the first optical coupling unit 110 optically connects the first optical fiber 200 to the light-emitting element 41 of the transmitter 40.

[0040] The first optical coupling section 110 includes a first ferrule 111 and a first lens 113. The first optical fiber 200 is inserted into the first ferrule 111. The first ferrule 111 extends along the stacking direction (Y direction) of the multilayer substrate 10. The first ferrule 111 fixes the first optical fiber 200 and aligns the optical axis C1 of the first optical fiber 200 with the optical axis C2 of the light-emitting element 41.

[0041] The first lens 113 is provided in the opening 111a of the first ferrule 111. With the first ferrule 111 fixing the first optical fiber 200, the end face 201 of the first optical fiber 200 faces the first lens 113. The first lens 113 collects the transmitted light sent from the light-emitting element 41 and inputs the transmitted light to the end face 201 of the first optical fiber 200. The end face 201 is also referred to as the first end face.

[0042] Alternatively, instead of providing the first lens 113, the end face 201 of the first optical fiber 200 may be processed so that the end face 201 functions as a lens. In this case, when the first ferrule 111 is fixed to the first optical fiber 200, the end face 201 of the first optical fiber 200 is exposed to the outside of the optical connector 100.

[0043] The second optical coupling unit 120 is connected to the second optical fiber 300. With the optical connector 100 connected to the optical transceiver module 1, the second optical coupling unit 120 optically connects the second optical fiber 300 to the photodetector element 51 of the receiver 50 via the optical waveguide 30.

[0044] The second optical coupling section 120 includes a second ferrule 121 and a second lens 123. The second optical fiber 300 is inserted into the second ferrule 121. The second ferrule 121 is positioned alongside the first ferrule 111 and extends along the stacking direction (Y direction) of the multilayer substrate 10. The second ferrule 121 fixes the second optical fiber 300 and aligns the optical axis C3 of the second optical fiber 300 with the optical axis C4 of the photodetector 51. With this configuration, when the first optical fiber 200 and the second optical fiber 300 are connected to the first optical coupling section 110 and the second optical coupling section 120, respectively, the second optical fiber 300 is positioned alongside the first optical fiber 200.

[0045] The second lens 123 is provided in the aperture 121a of the second ferrule 121. With the second ferrule 121 fixing the second optical fiber 300, the end face 301 of the second optical fiber 300 faces the second lens 123. The second lens 123 forms the received light output from the end face 301 of the second optical fiber 300 into parallel light and propagates the received light into the optical waveguide 30. The end face 301 is also referred to as the second end face.

[0046] Alternatively, instead of providing the second lens 123, the end face 301 of the second optical fiber 300 may be processed so that the end face 301 functions as a lens. In this case, when the second ferrule 121 is fixed to the second optical fiber 300, the end face 301 of the second optical fiber 300 is exposed to the outside of the optical connector 100.

[0047] The optical connector 100 may use an optical fiber array to secure the first optical fiber 200 and the second optical fiber 300 instead of the first ferrule 111 and the second ferrule 121. In this case, the first lens 113 and the second lens 123 are included in a lens array facing the optical fiber array.

[0048] [Configuration of the first and second optical fibers] Next, the configurations of the first optical fiber 200 and the second optical fiber 300 will be described. Since the configuration of the second optical fiber 300 is the same as that of the first optical fiber 200, only the configuration of the first optical fiber 200 will be described.

[0049] The first optical fiber 200 is exposed from the optical fiber cable at the end of the optical fiber cable and inserted into the first ferrule 111. The first optical fiber 200 consists of a core, cladding, and sheath. In a cross-section of the first optical fiber 200, the core is located in the center of the first optical fiber 200. The cladding is arranged to surround the core. The sheath is arranged to surround the cladding.

[0050] The refractive index of the core is higher than that of the cladding. Thus, in the first optical fiber 200, the core is covered by cladding with a lower refractive index than the core, so the transmitted light input to the end face 201 of the first optical fiber 200 is confined inside the core and propagates within the core.

[0051] In this embodiment, the first optical fiber 200 is a multimode optical fiber. Therefore, the core diameter of the first optical fiber 200 is larger than that of a single-mode optical fiber. Since the first optical fiber 200 has multiple propagation modes, mode division multiplexing communication can be performed to transmit multiple types of data simultaneously by associating data with each of the multiple propagation modes.

[0052] [Operation of the optical transceiver module] Next, the operation of the optical transceiver module will be explained. In the transmitter 40, the light-emitting element 41, under the control of the driver IC 43, converts an electrical signal into an optical signal and transmits light upward (+Y side) toward the optical transceiver module 1. The transmitted light transmitted from the light-emitting element 41 is focused by the first lens 113 and input to the end face 201 of the first optical fiber 200.

[0053] Meanwhile, in the receiver 50, the photodetector 51 receives the received light output from the end face 301 of the second optical fiber 300 via the optical waveguide 30. Specifically, the received light output from the end face 301 of the second optical fiber 300 is formed into parallel light by the second lens 123, propagates through the optical waveguide 30, is focused by the focusing lens 57, and is received by the photodetector 51. Upon receiving the received light, the photodetector 51 converts the optical signal into an electrical signal. The amplifier IC 53 amplifies the electrical signal output from the photodetector 51.

[0054] [Comparative Example] Next, the configuration of the optical transceiver module 2, a comparative example, will be described. Figure 9 is a cross-sectional view of the optical transceiver module 2. As shown in Figure 9, the configuration of the optical transceiver module 2 differs from the configuration of the optical transceiver module 1 in the following ways: (1) The optical waveguide 30 is not formed on the multilayer substrate 10. (2) A light-receiving element 451 is used instead of the light-receiving element 51. (3) The condensing lens 57 is not provided on the light-receiving surface of the light-receiving element 451. (4) Connector housings (not shown) are provided on both sides of the multilayer substrate 10, one side and the other side.

[0055] The light-receiving element 451 is composed of, for example, a top-incident photodiode and receives received light from below (-Y side) of the optical transceiver module 2. The light-receiving element 451 is arranged on the second conductor layer 23 via the multilayer substrate 10 so as to face the light-emitting element 41.

[0056] With this configuration, the transmitter 40 is provided on one side (+Y side) of the multilayer substrate 10, and the receiver 50 is provided on the other side (-Y side). Therefore, the mounting area of ​​the transmitter 40 and receiver 50 can be reduced.

[0057] However, in the optical transceiver module 2, the light-emitting element 41 transmits light upward (+Y side) of the optical transceiver module 2, and the light-receiving element 451 receives light downward (-Y side) of the optical transceiver module 2. For this reason, the optical transceiver module 2 is provided with a connector housing for accommodating an optical connector having a first optical coupling portion 110 on one side (+Y side) of the multilayer substrate 10, and a connector housing for accommodating an optical connector having a second optical coupling portion 120 on the other side (-Y side). The first optical coupling portion 110 and the second optical coupling portion 120 are connected to a first optical fiber 200 and a second optical fiber 300, respectively.

[0058] In the optical transceiver module 2, with the first optical fiber 200 and the second optical fiber 300 connected to the first optical coupling unit 110 and the second optical coupling unit 120, respectively, the second optical fiber 300 is positioned opposite the first optical fiber 200, with the multilayer substrate 10 in between. As a result, the optical transceiver module 2 has a complex configuration, and the routing of the first optical fiber 200 and the second optical fiber 300 becomes difficult.

[0059] In contrast, in the optical transceiver module 1, the light-emitting element 41 transmits light upward (+Y side) of the optical transceiver module 1, and the light-receiving element 51 receives light from upward (+Y side) of the optical transceiver module 1 via the optical waveguide 30. For this reason, the optical transceiver module 1 is provided with a connector housing 60 that accommodates an optical connector 100 having a first optical coupling portion 110 and a second optical coupling portion 120 on only one side (+Y side) of the multilayer substrate 10. The first optical coupling portion 110 and the second optical coupling portion 120 are connected to a first optical fiber 200 and a second optical fiber 300, respectively.

[0060] In the optical transceiver module 1, with the first optical fiber 200 and the second optical fiber 300 connected to the first optical coupling unit 110 and the second optical coupling unit 120, respectively, the second optical fiber 300 is arranged alongside the first optical fiber 200. Therefore, the optical transceiver module 1 has a simple configuration and the routing of the first optical fiber 200 and the second optical fiber 300 is easy.

[0061] [Effects / Effects] According to this embodiment, the optical transceiver module 1 comprises a multilayer substrate 10, an optical waveguide 30, a transmitter 40, and a receiver 50. The multilayer substrate 10 has a substrate 11, a first conductor layer 21 facing one of the two surfaces of the substrate 11, and a second conductor layer 23 facing the other of the two surfaces of the substrate 11. The optical waveguide 30 penetrates the multilayer substrate 10.

[0062] The transmitter 40 is provided in the first conductor layer 21 and transmits light. The receiver 50 is provided in the second conductor layer 23 so as to face the optical waveguide 30 and receives light. The transmitted light is transmitted from the transmitter 40 and input to the end face 201 of the first optical fiber 200 which faces the transmitter 40 in the stacking direction (Y direction) of the multilayer substrate 10. The received light is output from the end face 301 of the second optical fiber 300 which is arranged alongside the first optical fiber 200 and faces the receiver 50 via the optical waveguide 30, propagates through the optical waveguide 30 and is received by the receiver 50.

[0063] With the above configuration, the transmitter 40 is provided on one side (+Y side) of the substrate 11, and the receiver 50 is provided on the other side (-Y side). This makes it possible to reduce the mounting area of ​​the transmitter 40 and the receiver 50.

[0064] With the configuration described above, the transmitted light is transmitted perpendicular to the substrate surface, so a surface-emitting laser such as a VCSEL can be used as the light source for the transmitter 40. This reduces power consumption.

[0065] With the above configuration, in the optical transceiver module 1, the transmitter 40 transmits light to one side (+Y side) of the multilayer substrate 10, and the receiver 50 receives light from one side (+Y side) of the multilayer substrate 10 via the optical waveguide 30. This allows the first optical fiber 200 and the second optical fiber 300 to be placed side by side on one side (+Y side) of the multilayer substrate 10.

[0066] Therefore, by using the optical transceiver module 1, power consumption can be reduced while keeping the mounting area of ​​the transmitter 40 and receiver 50 low with a simple configuration.

[0067] Furthermore, as described above, the optical transceiver module 1 uses a multilayer substrate 10. Therefore, the transmitter 40 and receiver 50 can be positioned far apart from each other in the stacking direction (Y direction) of the multilayer substrate 10. This reduces the degree of electrical coupling between the transmitter 40 and receiver 50, thereby suppressing noise superposition.

[0068] With the configuration described above, in the optical transceiver module 1, the transmitter 40 and receiver 50 are not arranged side by side on either side (+Y side) or the other side (-Y side) of the substrate 11. Therefore, it is possible to suppress the electrical coupling between the conductor provided in the transmitter 40 and the conductor provided in the receiver 50.

[0069] With the above configuration, the light-emitting surface of the transmitter 40 and the light-receiving surface of the receiver 50 can be positioned at different locations in the stacking direction (Y direction) of the multilayer substrate 10. Therefore, it is possible to prevent some of the transmitted light from the transmitter 40 from being received by the receiver 50 as stray light.

[0070] According to this embodiment, the inner surface of the optical waveguide 30 is plated with gold 35.

[0071] The above configuration makes it possible to increase the reflectivity within the optical waveguide 30. Therefore, it is possible to efficiently improve the optical connection (degree of optical coupling) between the second optical fiber 300 and the receiver 50 with a simple configuration.

[0072] According to this embodiment, the receiver 50 has a back-incident photodiode for receiving received light, and the transmitter 40 has a VCSEL for transmitting transmitted light.

[0073] With the configuration described above, the optical transceiver module 1 can transmit light from one side (+Y side) of the multilayer substrate 10 with low power consumption using a VCSEL. Furthermore, the optical transceiver module 1 can receive received light from one side (+Y side) of the multilayer substrate 10 via the optical waveguide 30 using a back-side incident photodiode. Therefore, by using the optical transceiver module 1, power consumption can be reduced while keeping the mounting area of ​​the transmitter 40 and receiver 50 low with a simple configuration.

[0074] According to this embodiment, a condensing lens 57 is provided on the light-receiving surface of the back-side incident photodiode. The condensing lens 57 is located within the optical waveguide 30.

[0075] The above configuration allows for a larger light-receiving diameter of the back-side-incident photodiode. Therefore, even when using a multimode optical fiber with a large core diameter as the second optical fiber 300, the optical connection (optical coupling) between the second optical fiber 300 and the receiver 50 can be efficiently improved with a simple configuration.

[0076] [First variation] In the embodiment described above, with the optical connector 100 housed in the connector housing 60 of the optical transceiver module 1, the tip of the second lens 123 is set to be in the same position as the tip of the first lens 113 in the stacking direction (Y direction) of the multilayer substrate 10, but the embodiment is not limited to this.

[0077] Figure 2 is a cross-sectional view of the optical transceiver module 1A. As shown in Figure 2, in this modified example, with the optical connector 100 housed in the connector housing 60 of the optical transceiver module 1A, the tip of the second lens 123 is set to be closer to the first conductor layer 21 than the tip of the first lens 113 in the stacking direction (Y direction) of the multilayer substrate 10.

[0078] Therefore, when the first optical fiber 200 and the second optical fiber 300 are connected to the first optical coupling portion 110 and the second optical coupling portion 120 of the optical connector 100, respectively, the end face 301 of the second optical fiber 300 is positioned closer to the first conductor layer 21 than the end face 201 of the first optical fiber 200 in the stacking direction (Y direction) of the multilayer substrate 10.

[0079] According to this modified example, in the stacking direction (Y direction) of the multilayer substrate 10, the distance between the end face 301 of the second optical fiber 300 and the first conductor layer 21 is shorter than the distance between the end face 201 of the first optical fiber 200 and the first conductor layer 21.

[0080] With the above configuration, it is possible to suppress the leakage of some of the transmitted light from the transmitter 40 to the receiver 50.

[0081] [Second variation] In the first modified example described above, the surface (+Y side) and back surface (-Y side) of the multilayer substrate 10 were flat, but the invention is not limited to this.

[0082] Figure 3 is a cross-sectional view of the optical transceiver module 1B. As shown in Figure 3, in this modified example, cavities are formed on the front (+Y side) and back (-Y side) of the multilayer substrate 10 of the optical transceiver module 1B. A transmitter 40 is housed in the cavity formed on the front (+Y side) of the multilayer substrate 10. A receiver 50 is housed in the cavity formed on the back (-Y side) of the multilayer substrate 10.

[0083] Specifically, a first through-hole 70 is formed in the first outer substrate 13 and the first conductor layer 21. The transmitter 40 is housed within the first through-hole 70. In the stacking direction of the multilayer substrate 10, the depth of the first through-hole 70 is greater than or equal to the height of the transmitter 40 (light-emitting element 41 and driver IC 43). This configuration makes it possible to reduce the height of the optical transceiver module 1B.

[0084] The third conductor layer 25 is exposed within the first through-hole 70. The third conductor layer 25 within the first through-hole 70 is also referred to as the first surface conductor layer.

[0085] Within the first through-hole 70, the transmitter 40 is provided in the third conductor layer 25. The third conductor layer 25 has circuit patterns 25a and 25b to the right (-X side) of the optical waveguide 30, and circuit pattern 25c to the left (+X side) of the optical waveguide 30. Circuit pattern 25b is located to the right (-X side) of circuit pattern 25a.

[0086] Circuit pattern 25a is not connected to circuit patterns 25b and 25c, and is not electrically connected to them. Furthermore, circuit patterns 25a to 25c are not connected to the optical waveguide 30, and are not electrically connected to the optical waveguide 30.

[0087] The light-emitting element 41 is located in the circuit pattern 25a of the third conductor layer 25. The driver IC 43 is located in the circuit pattern 25b of the third conductor layer 25. The circuit pattern 25a is also referred to as the area where the light-emitting element 41 (e.g., VCSEL) of the transmitter 40 is located. The circuit patterns 25b and 25c are also referred to as other areas.

[0088] In this modified example, the third conductor layer 25 forms the ground for the circuit pattern of the first conductor layer 21. In this configuration, the driver IC 43 is electrically connected to the circuit pattern of the first conductor layer 21 by bonding wires 47.

[0089] In the stacking direction (Y direction) of the multilayer substrate 10, if the depth of the first through-hole 70 is equal to the height of the transmitter 40 (light-emitting element 41 and driver IC 43), the first conductor layer 21 will be at the same position as the top surface of the driver IC 43. Therefore, the length of the bonding wire 47 that electrically connects the driver IC 43 to the first conductor layer 21 can be minimized.

[0090] A second through-hole 80 is formed in the second outer substrate 15 and the second conductor layer 23. The receiver 50 is housed within the second through-hole 80. In the stacking direction of the multilayer substrate 10, the depth of the second through-hole 80 is greater than or equal to the height of the receiver 50 (photodetector 51 and amplifier IC 53). This configuration makes it possible to reduce the height of the optical transceiver module 1B.

[0091] The fourth conductor layer 27 is exposed within the second through-hole 80. The fourth conductor layer 27 within the second through-hole 80 is also referred to as the second surface conductor layer.

[0092] Within the second through-hole 80, the receiver 50 is provided in the fourth conductor layer 27. The fourth conductor layer 27 has circuit patterns 27a and 27b to the right (-X side) of the optical waveguide 30, and circuit pattern 27c to the left (+X side) of the optical waveguide 30. Circuit pattern 27b is located to the right (-X side) of circuit pattern 27a.

[0093] Circuit pattern 27a is not connected to circuit patterns 27b and 27c, and is not electrically connected to them. Furthermore, circuit patterns 27b and 27c are not connected to the optical waveguide 30, and are not electrically connected to the optical waveguide 30.

[0094] The light-receiving element 51 is located in the circuit pattern 27a of the fourth conductor layer 27, and the amplifier IC 53 is located in the circuit pattern 27b of the fourth conductor layer 27. The circuit pattern 27a is also referred to as the area where the light-receiving element 51 (for example, a back-side incidence photodiode) of the receiver 50 is located. The circuit patterns 27b and 27c are also referred to as other areas.

[0095] In this modified example, the fourth conductor layer 27 forms the ground for the circuit pattern of the second conductor layer 23. In this configuration, the amplifier IC 53 is electrically connected to the circuit pattern of the second conductor layer 23 by bonding wires 59.

[0096] In the stacking direction of the multilayer substrate 10, if the depth of the second through-hole 80 is equal to the height of the receiver 50 (photodetector 51 and amplifier IC 53), the second conductor layer 23 will be at the same position as the top surface of the amplifier IC 53. Therefore, the length of the bonding wire 59 that electrically connects the amplifier IC 53 to the second conductor layer 23 can be minimized.

[0097] In this modified example, in a cross-sectional view of the optical transceiver module 1B, the optical waveguide 30 is formed in a stepped shape and has a large-diameter portion 30a and a small-diameter portion 30b. The large-diameter portion 30a penetrates the first outer substrate 13 and the first conductor layer 21. The small-diameter portion 30b penetrates the substrate 11, the third conductor layer 25, and the fourth conductor layer 27. The diameter of the small-diameter portion 30b is smaller than the diameter of the large-diameter portion 30a, and larger than the lens diameter of the focusing lens 57 provided on the light-receiving element 51.

[0098] The large-diameter portion 30a has an opening 31a in the first conductor layer 21, and the small-diameter portion 30b has an opening 33a in the fourth conductor layer 27. The focusing lens 57 is positioned within the optical waveguide 30 through the opening 33a of the small-diameter portion 30b. The circuit pattern 27a of the fourth conductor layer 27 is provided around the opening 33a of the small-diameter portion 30b. The large-diameter portion 30a and the small-diameter portion 30b are also referred to as the second portion and the first portion, respectively.

[0099] In this modified example, a light-absorbing film 37 (for example, a black resist) is applied around the opening 31a of the large-diameter portion 30a in the first conductor layer 21 and on the inner surface of the optical waveguide 30 instead of gold plating 35. This suppresses the reception of a portion of the transmitted light transmitted from the light-emitting element 41, ambient light, etc., as received light by the photodetector 51, thereby improving the receiving sensitivity of the photodetector 51.

[0100] In this modified configuration, one side of the substrate 11 is provided with a first conductor layer 21 and a third conductor layer 25 positioned between the substrate 11 and the first conductor layer 21, and a first outer substrate 13 is provided between the first conductor layer 21 and the third conductor layer 25. A first through-hole 70 is formed in the first conductor layer 21 and the first outer substrate 13, and the transmitter 40 is positioned within the first through-hole 70. In the stacking direction (Y direction) of the multilayer substrate 10, the depth of the first through-hole 70 is greater than or equal to the height of the transmitter 40.

[0101] On the other side of the substrate 11, a second conductor layer 23 and a fourth conductor layer 27 are provided, which are positioned between the substrate 11 and the second conductor layer 23. A second outer substrate 15 is provided between the second conductor layer 23 and the fourth conductor layer 27. A second through-hole 80 is formed in the second conductor layer 23 and the second outer substrate 15, and the receiver 50 is positioned within the second through-hole 80. In the stacking direction of the multilayer substrate 10, the depth of the second through-hole 80 is greater than or equal to the height of the receiver 50.

[0102] With the configuration described above, the transmitter 40 and the receiver 50 are located within the first through-hole 70 and the second through-hole 80, respectively. This allows for a lower profile for the optical transceiver module 1B.

[0103] The above configuration allows the distance between the end face 301 of the second optical fiber 300 and the receiver 50 to be shortened. Therefore, the optical connection (degree of optical coupling) between the second optical fiber 300 and the receiver 50 can be increased more efficiently.

[0104] In this modified example, the first conductor layer 21 has a circuit pattern, and the third conductor layer 25 forms the ground for the circuit pattern of the first conductor layer 21. The transmitter 40 is provided on the third conductor layer 25, and the portion of the third conductor layer 25 where the VCSEL is provided as the light-emitting element 41 is not connected to other portions.

[0105] The second conductor layer 23 has a circuit pattern, and the fourth conductor layer 27 forms the ground for the circuit pattern of the second conductor layer 23. The receiver 50 is provided on the fourth conductor layer 27, and the portion of the fourth conductor layer 27 where the back-incident photodiode is provided as the light-receiving element 51 is not connected to other portions.

[0106] The above configuration makes it possible to suppress parasitic capacitance between the VCSEL and ground, and between the back-illuminated photodiode and ground. Therefore, it is possible to prevent a decrease in signal quality due to deterioration of frequency response characteristics.

[0107] According to this modified example, the optical waveguide 30 has a small-diameter portion 30b that penetrates the substrate 11, the third conductor layer 25, and the fourth conductor layer 27, and a large-diameter portion 30a that penetrates the first outer substrate 13 and the first conductor layer 21. The diameter of the small-diameter portion 30b is smaller than the diameter of the large-diameter portion 30a. An optical absorbing film is coated on the inner surface of the optical waveguide 30.

[0108] With the above configuration, the receiver 50 can suppress the reception of a portion of the transmitted light from the transmitter 40, ambient light, etc., as received light, thereby improving the receiving sensitivity of the receiver 50.

[0109] [Third variation] In the second modified example described above, in the receiver 50, the light-receiving element 51 was electrically connected to the amplifier IC 53 by bonding wire 55, and the amplifier IC 53 was electrically connected to the circuit pattern of the second conductor layer 23 by bonding wire 59, but the invention is not limited to this.

[0110] Figure 4 is a cross-sectional view of the optical transceiver module 1C. As shown in Figure 4, in this modified example, the photodetector 51 and amplifier IC 53 in the optical transceiver module 1C are flip-chip mounted instead of wire-bonded.

[0111] Specifically, the light-receiving element 51 is electrically connected to the circuit pattern 27a of the fourth conductor layer 27 by a solder bump 510 made of solder balls. The amplifier IC 53 is electrically connected to the circuit patterns 27a and 27b of the fourth conductor layer 27 by a solder bump 520 made of solder balls. With this configuration, the light-receiving element 51 is electrically connected to the amplifier IC 53 via the circuit pattern 27a.

[0112] This configuration allows for appropriate adjustment of the heights of the photodetector 51 and amplifier IC 53 in the stacking direction of the multilayer substrate 10. Furthermore, when heat sinks are provided on the photodetector 51 and amplifier IC 53 for heat dissipation, the absence of bonding wires 55 and 59 improves the flexibility of heat sink placement.

[0113] [Fourth variation] In the embodiments described above, the first opening 31 of the optical waveguide 30 in the first conductor layer 21 was open, but the embodiment is not limited to this.

[0114] Figure 5 is a cross-sectional view of the main part of the optical transceiver module 1D. In Figure 5, the transmitter 40, connector housing 60, and optical connector 100 are not shown. As shown in Figure 5, in this modified example, a focusing lens 400 is provided at the first opening 31 of the optical waveguide 30 in the first conductor layer 21. As a result, the first opening 31 is closed by the focusing lens 400.

[0115] The focusing lens 400 focuses the received light output from the second lens 123 of the second optical coupling section 120 of the optical connector 100, and causes the focusing lens 57 to receive the received light. In this way, the focusing lens 400 is optically connected to the light-receiving element 51 via the focusing lens 57.

[0116] In this modified example, a focusing lens 400 is provided at the first opening 31 of the optical waveguide 30 formed in the first conductor layer 21. With the above configuration, the first opening 31 of the optical waveguide 30 in the first conductor layer 21 is closed by the focusing lens 400, thus preventing foreign matter from entering the optical waveguide 30. Furthermore, by focusing the received light with the focusing lens 400, the optical connection (degree of optical coupling) between the second optical fiber 300 and the receiver 50 can be more efficiently improved.

[0117] [Fifth variation] In the embodiment described above, with the optical connector 100 housed in the connector housing 60 of the optical transceiver module 1, the second ferrule 121 and the second optical fiber 300 were arranged above (+Y side) the optical waveguide 30, but the embodiment is not limited to this.

[0118] Figure 6 is a cross-sectional view of the main part of the optical transceiver module 1E. In Figure 6, the transmitter 40, the connector housing 60, and a portion of the optical connector 100 are not shown. As shown in Figure 6, in this modified example, the end face 301a of the second optical fiber 300 is located within the optical waveguide.

[0119] Specifically, in a cross-sectional view of the optical transceiver module 1E, the optical waveguide 30 is formed in a stepped shape and has a large-diameter portion 30A and a small-diameter portion 30B. The large-diameter portion 30A penetrates the substrate 11, the first outer substrate 13, the first conductor layer 21, and the third conductor layer 25. The small-diameter portion 30B penetrates the second outer substrate 15, the second conductor layer 23, and the fourth conductor layer 27. The diameter of the small-diameter portion 30B is smaller than the diameter of the large-diameter portion 30A, and larger than the lens diameter of the focusing lens 57 provided on the light-receiving element 51.

[0120] The end of the second optical fiber 300 is exposed from the second ferrule 121 of the second optical coupling 120 and inserted into the optical waveguide 30. For this reason, in this modified example, the second lens 123 is not provided at the opening 121a of the second ferrule 121.

[0121] With the end of the second optical fiber 300 inserted into the optical waveguide 30, the end face 301a of the second optical fiber 300 is positioned within the large-diameter portion 30A and faces the light-receiving element 51 via the focusing lens 57.

[0122] The focusing lens 57 is positioned within the small-diameter section 30B via the second aperture 33 of the optical waveguide 30. The focusing lens 57 focuses the received light that enters the small-diameter section 30B from the end face 301a of the second optical fiber 300 and propagates through the small-diameter section 30B, causing the received light to be received by the light-receiving surface of the light-receiving element 51.

[0123] Furthermore, gold plating 35 is applied to the area around the first opening 31 of the optical waveguide 30 in the first conductor layer 21, and to the inner surface of the optical waveguide 30. In addition, the tip of the second optical fiber 300 is tapered.

[0124] In this modified configuration, the end face 301a of the second optical fiber 300 is located within the optical waveguide 30. With the above configuration, the distance between the end face 301a of the second optical fiber 300 and the receiver 50 can be shortened. Therefore, the optical connection (degree of optical coupling) between the second optical fiber 300 and the receiver 50 can be further efficiently improved. The distance between the end face 301a of the second optical fiber 300 and the receiver 50 is adjusted by adjusting the thickness of the second outer substrate 15.

[0125] Although Figure 6 shows the end of the second optical fiber 300 inserted into the optical waveguide 30, the design is not limited to this. Instead of the second optical fiber 300, the end of the second ferrule 121 may be inserted into the optical waveguide 30. In this case, the diameter of the large-diameter section 30A of the optical waveguide 30 is determined according to the diameter of the second ferrule 121. Furthermore, the second optical coupling section 120 may be housed within the optical waveguide 30.

[0126] [Sixth variation] In the embodiment described above, the diameter of the optical waveguide 30 was set to be larger than the lens diameter of the focusing lens 57, but the embodiment is not limited to this.

[0127] Figure 7 is a cross-sectional view of the main part of the optical transceiver module 1F. In Figure 7, the transmitter 40, the connector housing 60, and a portion of the optical connector 100 are omitted from the illustration. As shown in Figure 7, in this modified example, the diameter of the optical waveguide 30 is set to be substantially the same as the diameter of the focusing lens 57.

[0128] Specifically, in a cross-sectional view of the optical transceiver module 1F, a recess 90 is formed on the other side (-Y side) of the multilayer substrate 10. The condensing lens 57 is positioned within the recess 90.

[0129] The optical waveguide 30 penetrates the multilayer substrate 10. The optical waveguide 30 has a first opening 31 in the first conductor layer 21 and a second opening 33 on the bottom surface of the recess 90. Gold plating 35 is applied around the first opening 31 of the optical waveguide 30 in the first conductor layer 21 and on the inner surface of the optical waveguide 30.

[0130] Within the recess 90, the focusing lens 57 focuses the received light propagating through the optical waveguide 30 via the second opening 33 of the optical waveguide 30. With this configuration, the focusing lens 57 focuses the received light that enters the optical waveguide 30 from above (+Y side) of the optical transceiver module 1F and propagates through the optical waveguide 30, and receives the received light on the light-receiving surface of the light-receiving element 51.

[0131] In this modified example, the third conductor layer 25 forms the ground for the circuit pattern of the first conductor layer 21, so the circuit patterns 25A and 25B of the third conductor layer 25 are not connected to the optical waveguide 30. Similarly, the fourth conductor layer 27 forms the ground for the circuit pattern of the second conductor layer 23, so the circuit patterns 27A and 27B of the fourth conductor layer 27 are not connected to the optical waveguide 30. By providing a gap between the circuit patterns 25A and 25B of the third conductor layer 25 and the optical waveguide 30, and by providing a gap between the circuit patterns 27A and 27B of the fourth conductor layer 27 and the optical waveguide 30, it is possible to suppress the occurrence of parasitic capacitance between the photodetector 51 and the ground.

[0132] [7th variation] In the fifth modified example described above, the light-receiving element 51 in the receiver 50 was electrically connected to the amplifier IC 53 by a bonding wire 55, but the invention is not limited to this.

[0133] Figure 8 is a cross-sectional view of the optical transceiver module 1G. As shown in Figure 8, in this modified example, the photodetector 51 and amplifier IC 53 in the optical transceiver module 1G are flip-chip mounted instead of wire-bonded.

[0134] Specifically, the light-receiving element 51 is electrically connected to the circuit pattern 23B of the second conductor layer 23 by a solder bump 510 made of solder balls. The amplifier IC 53 is electrically connected to the circuit patterns 23A and 23B of the second conductor layer 23 by a solder bump 520 made of solder balls. With this configuration, the light-receiving element 51 is electrically connected to the amplifier IC 53 via the circuit pattern 23B.

[0135] In this modified example, gold plating 35a is applied only to the inner surface of the small-diameter portion 30B of the optical waveguide 30.

[0136] Furthermore, in this modified example, the third conductor layer 25 forms the ground for the circuit pattern of the first conductor layer 21, so the circuit patterns 25A and 25B of the third conductor layer 25 are not connected to the optical waveguide 30. Similarly, the fourth conductor layer 27 forms the ground for the circuit pattern of the second conductor layer 23, so the circuit patterns 27A and 27B of the fourth conductor layer 27 are not connected to the optical waveguide 30. By providing a gap between the circuit patterns 25A and 25B of the third conductor layer 25 and the optical waveguide 30, and by providing a gap between the circuit patterns 27A and 27B of the fourth conductor layer 27 and the optical waveguide 30, it is possible to suppress the occurrence of parasitic capacitance between the photodetector 51 and the ground.

[0137] [Other variations] In the embodiments described above, the transmitter 40 and receiver 50 may be filled and sealed with resin. This protects the transmitter 40 and receiver 50 from external impacts, environmental changes, and the like.

[0138] In the embodiments described above, the light-emitting element 41 and the driver IC 43 may be mounted using a flip-chip method instead of wire bonding.

[0139] In the above-described modifications 3 to 5 and 7, the optical waveguide 30 was formed in a stepped shape in the cross-sectional view of the optical transceiver modules 1B, 1C, 1E, and 1G, but it is not limited to this and may be formed in a tapered shape.

[0140] Furthermore, an optical transceiver module may be formed by combining two or more configurations from the above-described embodiments, the first to seventh modifications, and other modifications.

[0141] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment. [Explanation of Symbols]

[0142] 1.1A~1G Optical Transceiver Module 10 Multilayer board 11 circuit boards 13 First outer board 15 Second outer board 21 First Conductor Layer 23 Second Conductor Layer 25 Third Conductor Layer 27. Fourth Conductor Layer 30 Optical waveguide 30a Large diameter section 30b Small diameter section 31 First opening 35 gold plated 37 Light-absorbing film 40 Transmitters 41 Light-emitting element 50 Receiver 51 Light-receiving element 57 Focusing lens 70 First through hole 80 Second through hole 200 First Optical Fiber 201 End face 300 Second Optical Fiber 301 End face 400 Focusing Lens

Claims

1. A multilayer substrate having a substrate, a first surface conductor layer facing one of the two surfaces of the substrate, and a second surface conductor layer facing the other of the two surfaces of the substrate, An optical waveguide penetrating the multilayer substrate, A transmitter provided on the first surface conductor layer for transmitting light, A receiver is provided on the second surface conductor layer so as to face the optical waveguide, and receives the received light. Equipped with, The transmitted light is transmitted from the transmitter and input to the first end face of the first optical fiber facing the transmitter in the stacking direction of the multilayer substrate. An optical transceiver module in which the received light is output from the second end face of a second optical fiber, which is arranged alongside the first optical fiber and faces the receiver via the optical waveguide, propagates through the optical waveguide, and is received by the receiver.

2. The optical transceiver module according to claim 1, wherein, in the stacking direction of the multilayer substrate, the distance between the second end face of the second optical fiber and the first surface conductor layer is shorter than the distance between the first end face of the first optical fiber and the first surface conductor layer.

3. The optical transceiver module according to claim 1, wherein the inner surface of the optical waveguide is gold-plated.

4. The optical transceiver module according to claim 1, wherein a focusing lens is provided at the opening of the optical waveguide formed in the first surface conductor layer.

5. The optical transceiver module according to claim 1, wherein the second end face of the second optical fiber is located within the optical waveguide.

6. The receiver has a back-incident photodiode for receiving the received light, The optical transceiver module according to claim 1, wherein the transmitter has a vertical-cavity surface-emitting laser that transmits the transmitted light.

7. A condensing lens is provided on the light-receiving surface of the aforementioned back-side incident photodiode. The optical transceiver module according to claim 6, wherein the focusing lens is disposed within the optical waveguide.

8. One side of the substrate is provided with a first conductor layer and a third conductor layer disposed between the substrate and the first conductor layer. A first outer substrate is provided between the first conductor layer and the third conductor layer. The first conductor layer and the first outer substrate have a first through hole formed therein. Within the first through-hole, the third conductor layer corresponds to the first surface conductor layer. The transmitter is located inside the first through-hole, In the stacking direction of the multilayer substrate, the depth of the first through-hole is greater than or equal to the height of the transmitter. On the other side of the substrate, a second conductor layer and a fourth conductor layer disposed between the substrate and the second conductor layer are provided. A second outer substrate is provided between the second conductor layer and the fourth conductor layer. The second conductor layer and the second outer substrate have a second through-hole formed therein. Within the second through-hole, the fourth conductor layer corresponds to the second surface conductor layer. The receiver is located inside the second through-hole, The optical transceiver module according to claim 7, wherein, in the stacking direction of the multilayer substrate, the depth of the second through-hole is greater than or equal to the height of the receiver.

9. The first conductor layer has a first circuit pattern, The third conductor layer forms the ground of the first circuit pattern. The transmitter is provided in the third conductor layer, In the third conductive layer, the portion where the vertical cavity type surface-emitting laser is provided is not connected to other portions. The second conductor layer has a second circuit pattern, The fourth conductor layer forms the ground of the second circuit pattern. The receiver is provided in the fourth conductor layer, The optical transceiver module according to claim 8, wherein the portion of the fourth conductor layer on which the back-surface incident photodiode is provided is not connected to other portions.

10. The optical waveguide has a first portion that penetrates the substrate, the third conductor layer, and the fourth conductor layer, and a second portion that penetrates the first outer substrate and the first conductor layer. The diameter of the first part is smaller than the diameter of the second part. The optical transceiver module according to claim 8, wherein an optical absorbing film is coated on the inner surface of the optical waveguide.

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