Optical module
The optical module achieves efficient optical connection by aligning the optical waveguide and light emitting/receiving elements on separate sides of the substrate, using an optical element to focus light, addressing alignment challenges in existing designs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CITIZEN ELECTRONICS CO LTD
- Filing Date
- 2026-01-15
- Publication Date
- 2026-07-23
AI Technical Summary
Existing optical modules face challenges in precisely positioning the optical waveguide, light receiving element, and light emitting element with respect to the optical path conversion member, leading to inefficiencies in optical connection between optical fibers and electronic devices.
The optical module design includes a substrate with an opening, where the optical waveguide is positioned on one side and the light emitting and receiving member is on the opposite side, allowing for precise alignment of light emitting and receiving portions with the optical waveguide's core portions, facilitated by an optical element that focuses light between these components.
This configuration enables efficient optical connection between optical fibers and electronic devices, reducing manufacturing complexity and improving alignment precision, thereby enhancing data transmission and reception capabilities.
Smart Images
Figure JP2026000997_23072026_PF_FP_ABST
Abstract
Description
Optical module
[0001] The present invention relates to an optical module.
[0002] An optical module for efficiently connecting an optical fiber and an electronic device capable of optical communication is known (see, for example, Japanese Patent Application Laid-Open No. 2020-56894).
[0003] In the optical module described in Japanese Patent Application Laid-Open No. 2020-56894, the light emitted from the optical waveguide is guided to the light receiving element by the optical path conversion member, and the light emitted from the light emitting element is guided to the optical waveguide by the optical path conversion member. Further, the optical waveguide is disposed on the optical conversion member, and the light receiving element and the light emitting element are disposed on the substrate. Furthermore, the optical path conversion member needs to be formed using optical components in order to transfer light between the optical waveguide and the light receiving element and the light emitting element.
[0004] However, in the optical module described in Japanese Patent Application Laid-Open No. 2020-56894, it is difficult to precisely position the optical waveguide, the light receiving element, and the light emitting element with respect to the optical path conversion member formed using optical components.
[0005] An object of the present disclosure is to provide an optical module capable of efficiently optically connecting an optical waveguide and an electronic device.
[0006] The optical module according to the present disclosure includes a substrate having an opening and capable of being connected to an electronic device, an optical waveguide disposed on the substrate and having a plurality of core portions, and a light emitting and receiving member disposed on the substrate on the side opposite to the side where the optical waveguide is disposed. The light emitting and receiving member includes a housing having a recess inside, a light emitting portion disposed inside the housing for emitting light toward a part of the plurality of core portions through the opening, and a light receiving portion disposed inside the housing for receiving light emitted from a part of the plurality of core portions through the opening.
[0007] In the optical module according to the present disclosure, it is preferable to further include an optical element disposed inside the housing between the plurality of core portions and the light emitting portion and the light receiving portion.
[0008] In the optical module according to this disclosure, it is preferable that the optical element focuses light emitted from a light-emitting section onto a portion of a plurality of core sections, and also focuses light emitted from a portion of the plurality of core sections onto a light-receiving section.
[0009] In the optical module relating to this disclosure, the light-emitting section is preferably a VCSEL.
[0010] In the optical module according to this disclosure, it is preferable that the module further comprises a circuit board disposed on a substrate for driving a light-emitting unit and a light-receiving unit.
[0011] In the optical module according to this disclosure, it is preferable that the optical waveguide is configured to be connectable to an optical fiber.
[0012] This disclosure makes it possible to provide an optical module that can efficiently optically connect an optical waveguide and electronic equipment.
[0013] This is a schematic perspective view of the optical module 1 according to the present disclosure. This is a cross-sectional view AA' of Figure 1. This is a cross-sectional view BB' of Figure 2. This is a schematic diagram of another light-receiving member 120. This is a cross-sectional view of the optical module 2 according to the present disclosure. This is a cross-sectional view of the optical module 3 using an optical receptacle. This is a cross-sectional view of the optical module 4 using another optical receptacle.
[0014] The optical module relating to this disclosure will be described below with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to those embodiments, but extends to the invention described in the claims and its equivalents.
[0015] Figure 1 is a schematic perspective view of the optical module 1 according to this disclosure, Figure 2 is a cross-sectional view AA' of Figure 1, and Figure 3 is a cross-sectional view BB' of Figure 2.
[0016] The optical module 1 is composed of a substrate 10, a light-receiving member 20, an optical waveguide 30, an optical fiber 40, a connector 50, a circuit board 60, and an interface 70, etc. The light-receiving member 20 is arranged on the upper surface of the substrate 1 in the figure, and the light-receiving member 20 is connected to the circuit board 60 by connecting wiring 61. The circuit board 60 is connected to an interface 70 for connecting to electronic equipment such as a server. The optical waveguide 30 is arranged on the lower surface of the substrate 1 in the figure, and an optical fiber 40, which is connected to an external device (other server, PC, etc.) not shown, is optically connected to the connector 50.
[0017] An opening 11 is formed in the substrate 10. The opening 11 has a shape that allows laser light emitted from the light-receiving member 20 and light emitted from the optical waveguide 30 to pass through.
[0018] The light-receiving and light-emitting member 20 is composed of a housing 21 having a recess 22 on the inside, a light-emitting unit 24 and a light-receiving unit 25 positioned at the bottom 23 of the housing 21, and an optical element 26 positioned between the light-emitting unit 24 and the light-receiving unit 25 and the optical waveguide 30, with the opening 11 in between. The optical element 26 is positioned on a step 27 provided on the inside of the housing 21.
[0019] The light-emitting unit 24 is composed of multiple semiconductor lasers, and for example, a VCSEL (Vertical Cavity Surface Emitting Laser) can be used. The light-emitting unit 24 is controlled by a control mechanism including a CPU, etc., included in the circuit on which the optical module 1 is located, so that it can emit laser light with an output corresponding to the data received from the electronic device. In Figures 1 to 3, the light-receiving unit 25 is formed from four light-receiving elements, but there is no limit to the number, and it may include fewer than four light-receiving elements or more than four light-receiving elements.
[0020] The light-receiving unit 25 includes multiple photodiodes and other light-receiving elements, and is configured to receive light emitted from the optical waveguide 30. The light received by the light-receiving unit 25 is converted into an electrical signal and transmitted to an electronic device by a control mechanism included in the circuit on which the optical module 1 is located. In Figures 1 to 3, the light-receiving unit 25 is formed from four light-receiving elements, but there is no limit to the number; it may include fewer than four light-receiving elements or more than four light-receiving elements.
[0021] Since the light emitted from the optical waveguide 30 corresponds to the light propagated through the optical fiber 40 connected to the external device, the optical module 1 enables data transmission and reception between the external device and the electronic device through the light-emitting unit 24 and the light-receiving unit 25.
[0022] The optical element 26 has a collimating function that makes the laser light emitted from the light-emitting unit 24 into parallel light, and a focusing function that concentrates the light, once it has been made into parallel light, toward the optical waveguide 30. Furthermore, the optical element 26 has a collimating function that makes the light emitted from the optical waveguide 30 into parallel light, and a focusing function that concentrates the light, once it has been made into parallel light, toward the light-receiving unit 25. The optical element 26 may be formed as an integrated optical element having all of the above functions, or it may be formed by combining multiple optical components formed for each individual function. Note that the optical module 1 does not necessarily have to have the optical element 26.
[0023] The optical waveguide 30 is composed of a core layer 31, multiple core portions 32 formed within the core layer 31, an upper cladding layer 33, a lower cladding layer 34, a side cladding layer 35, an upper support layer 36, a lower support layer 37, a mirror portion 38, and the like. The refractive index of the core portion 32 is higher than that of the upper cladding layer 33, the lower cladding layer 34, and the side cladding layer 35, so that light can be confined and propagated within the core portion 32.
[0024] The laser light emitted from the light-emitting unit 24 passes through the optical element 26, has its propagation direction changed by 90 degrees at the mirror unit 37, and is incident on a portion of the core unit 32. The laser light incident on the core unit 32 propagates through the core unit 32, passes through the connector 50, and is propagated towards external equipment via the optical fiber 40. The light propagated through the other core unit 32 via the optical fiber 40 and the connector 50 has its propagation direction changed by 90 degrees at the mirror unit 37, passes through the optical element 26, and is focused to the light-receiving unit 25.
[0025] In Figures 1 to 3, the optical waveguide 30 has a total of eight core sections 32 formed in the core layer 31: four core sections 32 into which laser light from the light-emitting section 24 is incident, and four core sections 32 that emit light toward the light-receiving section 25. However, there is no limit to the number of core sections 32; it may have fewer than eight core sections 32 or more than eight core sections 32.
[0026] The optical fiber 40 is, for example, an assembly of multiple optical fibers. As shown in Figure 3, if the optical waveguide 30 has eight core sections 32, the optical fiber 40 is composed of eight optical fibers, and the connector 50 optically connects the eight optical fibers and the eight core sections 32.
[0027] The circuit board 60 is composed of a DSP, amplifier, memory, etc., and controls the emission of laser light from the light-emitting unit 24 in accordance with data input from the electronic device via the interface 70. The circuit board 60 also controls the generation of data corresponding to the light received by the light-receiving unit 25 and transmits it to the electronic device via the interface 70. The connection wiring 62 output from the light-receiving member 20 is connected to the circuit board 60 via wiring not shown.
[0028] In the optical module 1, the light-receiving member 20 is placed on one side of the substrate 10, and the optical waveguide 30 is placed on the other side of the substrate 10. This makes it easy to position the light-emitting portion 24 and the light-receiving portion 25 of the light-receiving member 20 and the core portion 32 of the optical waveguide 30. In other words, since the light-receiving member 20 and the optical waveguide 30 can be positioned on the precisely formed substrate 10, it becomes possible to accurately and easily position the light-emitting portion 24 and the light-receiving portion 25 and the core portion 32. To do this, it is necessary to form an opening 11 in the substrate 10, but there is no difficulty in cutting out a part of the substrate 10 to create the opening.
[0029] On the other hand, if, for example, the light-receiving member 20 is positioned on the upper surface of the substrate 10 and the optical waveguide 30 is positioned above the light-receiving member 20, the manufacturing precision of the housing 21 of the light-receiving member 20 needs to be increased. The same applies when positioning the light-receiving member 20 on top of the optical waveguide 30. Therefore, it is extremely important to position the light-receiving member 20 on one side of the substrate 10 and the optical waveguide 30 on the other side of the substrate 10, with the opening 11 in between. This makes it possible to easily position the light-emitting portion 24 and light-receiving portion 25 of the light-receiving member 20 and the core portion 32 of the optical waveguide 30, thus enabling efficient optical connection between optical fibers and electronic devices.
[0030] In the optical module 1, the circuit board 60 is the part that generates the most heat in the operating environment. On the other hand, the light-emitting unit 24 and the light-receiving unit 25 may be affected by rising ambient temperatures. Therefore, in the optical module 1, the light-emitting and light-receiving members 20 and the circuit board 60 are arranged with a gap between them on the substrate 10, so that the heat generated on the circuit board 60 is less likely to be transferred to the light-emitting and light-receiving members 20. From this perspective, it is preferable that the substrate 10 be made of a material with low thermal conductivity, such as resin.
[0031] Figure 4 shows a schematic diagram of another light-receiving member 120, which is a modified example of the light-receiving member 20 in the optical module 1. In the light-receiving member 20 of the optical module 1 shown in Figures 1 to 3, the optical element 26 is positioned on a step 27 provided on the inside of the housing 21. On the other hand, in the light-receiving member 120, the housing 121 does not have a step, and the optical element 26 is fixed to the bottom 123 of the housing 121 by legs 127 and 128. The other configurations of the light-receiving member 120 are the same as those of the light-receiving member 20. In the light-receiving member 120, by preparing pre-designed legs 127 and 128, it is possible to avoid the effort of creating a step in the housing 121.
[0032] Figure 5 is a cross-sectional view of the optical module 2 according to this disclosure. Optical module 1 is connected to electronic equipment, etc., via an optical waveguide 30, an optically connected connector 50, and an optically connected optical fiber 40. However, it is also possible to connect to electronic equipment, etc., using only the optical waveguide 30, without using the connector 50 and the optical fiber 40. Optical module 2 is a module for connecting external equipment and electronic equipment, etc., via the optical waveguide 30. In Figure 5, components similar to those of optical module 1 are given the same numbers and their explanations are omitted.
[0033] The optical module 2 has a light-receiving and light-emitting member 20 located on the substrate 10 at the right end of the figure, and a light-receiving and light-emitting member 20' located on the substrate 10' at the left end of the figure. The light-receiving and light-emitting members 20 and 20' are optically connected to the optical waveguide 30. The substrate 10' has the same configuration as the substrate 10, and the light-receiving and light-emitting member 20' has the same configuration as the light-receiving and light-emitting member 20.
[0034] The light-receiving and light-emitting member 20 is connected to an electronic device via a circuit board 60 and an interface 70 (not shown), and the light-receiving and light-emitting member 20' can be connected to an external device via a circuit board 60' and an interface 70' (not shown). The circuit board 60' has the same configuration as the circuit board 60, and the interface 70' has the same configuration as the interface 70.
[0035] When an electronic device and an external device are connected using the optical module 2, the laser light emitted from the light-emitting section 24 of the light-receiving / light-emitting member 20 in response to data from the electronic device is received by the light-receiving section 25' of the light-receiving / light-receiving member 20' via the optical waveguide 30, and the data corresponding to the received light is transmitted to the external device. In this way, data transmission and reception are possible between the electronic device and the external device via the optical module 2.
[0036] In the optical module 2, the two light-receiving and light-emitting members are connected using an optical waveguide 30, but the two light-receiving and light-emitting members may also be connected using a connector 50 and an optical fiber 40.
[0037] Figure 6 is a cross-sectional view of the optical module 3 using an optical receptacle. In the optical module 3, an optical receptacle 80 is used instead of an optical waveguide, and the light-receiving member 20 and the optical fiber 40 are optically connected without using a connector 50. In Figure 6, components similar to those in optical module 1 are given the same numbers and their explanations are omitted.
[0038] The optical receptacle 80 is a lens array composed of multiple lenses. The optical receptacle 80 has four lenses for guiding the laser light emitted from the four light-emitting units 24 of the light-receiving and light-emitting member 20 to the four optical fibers 40, and four lenses for guiding the laser light from the four optical fibers 40 to the four light-receiving units 25 of the light-receiving and light-emitting member 20. The number of lenses included in the optical receptacle 80 is not limited to eight, and can be appropriately determined according to the number of optical fibers included in the optical fibers 40 and the number of light-emitting units 24 and light-receiving units 25 included in the light-receiving and light-emitting member 20.
[0039] Figure 7 is a cross-sectional view of optical module 4 using a different optical receptacle. In optical module 4, an optical receptacle 81 is used instead of an optical waveguide to optically connect the light-receiving member 20 and the optical fiber 40 without using a connector 50. In Figure 7, the same number is used for components similar to optical module 1, and their explanation is omitted. The difference between optical module 4 and optical module 3 is that the connection direction between the light-receiving member 20 and the optical fiber is different, and an optical receptacle with a corresponding shape is used. That is, in optical module 3, the connection direction of the optical fiber 40 is perpendicular to the laser light emitted from the light-emitting part 24 of the light-receiving member 20, whereas in optical module 4, the connection direction of the optical fiber 40 is parallel to the laser light emitted from the light-emitting part 24 of the light-receiving member 20.
[0040] The optical receptacle 81 is a lens array composed of multiple lenses. The optical receptacle 81 has four lenses for guiding the laser light emitted from the four light-emitting units 24 of the light-receiving member 20 to the four optical fibers 40, and four lenses for guiding the laser light from the four optical fibers 40 to the four light-receiving units 25 of the light-receiving member 20. The number of lenses included in the optical receptacle 81 is not limited to eight, and can be appropriately determined according to the number of optical fibers included in the optical fibers 40 and the number of light-emitting units 24 and light-receiving units 25 included in the light-receiving member 20.
[0041] Those skilled in the art will understand that various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present invention. For example, the embodiments and modifications described above may be combined as appropriate within the scope of the invention.
Claims
1. An optical module comprising: a substrate having an opening and connectable to an electronic device; an optical waveguide disposed on the substrate and having a plurality of core portions; and a light-receiving member disposed on the substrate on the side opposite to the side on which the optical waveguide is disposed, wherein the light-receiving member comprises: a housing having a recess inside; a light-emitting portion disposed inside the housing for emitting light toward a portion of the plurality of core portions through the opening; and a light-receiving portion disposed inside the housing for receiving light emitted from a portion of the plurality of core portions through the opening.
2. The optical module according to claim 1, further comprising an optical element located between the plurality of core portions, the light-emitting portion, and the light-receiving portion, and disposed inside the housing.
3. The optical module according to claim 2, wherein the optical element concentrates light emitted from the light-emitting portion to a portion of the plurality of core portions, and concentrates light emitted from a portion of the plurality of core portions to the light-receiving portion.
4. The optical module according to claim 1, wherein the light-emitting unit is a VCSEL.
5. The optical module according to claim 1, further comprising a circuit board disposed on the substrate for driving the light-emitting unit and the light-receiving unit.
6. The optical module according to any one of claims 1 to 5, wherein the optical waveguide is configured to be connectable to an optical fiber.