阅读说明：本技术 光模块 (Optical module ) 是由 今亚耶乃 于 2019-08-30 设计创作，主要内容包括：本发明提供光模块,该光模块能够在保持信号光及接收光的光耦合效率的同时,进行双向的光通信。本发明的光模块具有光电转换装置及光插座。光插座具有：第一光学面、第二光学面、透射反射部、凹部、以及第三光学面。在透射反射部中处于信号光的光路以外的位置,将透射反射部固定于凹部的内表面,使由第一光学面入射的信号光向第二光学面透射,且使由第二光学面入射的接收光向第三光学面反射。在沿着基板的法线方向观察时,凹部内的光路相对于第二光学面与凹部之间的光路倾斜。(The invention provides an optical module which can perform bidirectional optical communication while maintaining optical coupling efficiency of signal light and received light. The optical module of the present invention has a photoelectric conversion device and an optical receptacle. The optical receptacle includes: the optical device includes a first optical surface, a second optical surface, a transflective portion, a recess, and a third optical surface. The transmitting-reflecting portion is fixed to an inner surface of the recess portion at a position other than an optical path of the signal light in the transmitting-reflecting portion, transmits the signal light incident from the first optical surface to the second optical surface, and reflects the received light incident from the second optical surface to the third optical surface. The optical path within the recess is inclined with respect to the optical path between the second optical surface and the recess when viewed along the normal direction of the substrate.)

1. A light module, comprising:

a photoelectric conversion device having a substrate, a light emitting element disposed on the substrate, and a light receiving element disposed on the substrate; and

an optical receptacle, disposed above the photoelectric conversion device, for optically coupling the light emitting element and the light receiving element to an end surface of an optical transmission body when the optical receptacle is connected to the optical transmission body,

the optical receptacle has:

a first optical surface on which the signal light emitted from the light emitting element is incident;

a second optical surface for allowing the signal light incident from the first optical surface to exit to an end surface of the optical transmission body and allowing the received light exiting from the optical transmission body to enter;

a transmission/reflection unit that transmits the signal light incident from the first optical surface to the second optical surface and reflects the received light incident from the second optical surface to the light receiving element;

a recess for accommodating the transflective portion; and

a third optical surface for emitting the received light reflected by the transmission/reflection unit to the light receiving element,

fixing the transflective portion to an inner surface of the recess at a position out of an optical path of the signal light in the transflective portion,

an optical path within the recess is inclined with respect to an optical path between the second optical surface and the recess when viewed along a normal direction of the substrate.

2. The light module of claim 1,

the optical device further includes a reflecting surface disposed on an optical path between the first optical surface and the concave portion, and configured to reflect light incident from the first optical surface toward the transmitting/reflecting portion.

3. A light module, comprising:

a photoelectric conversion device having a substrate, a light emitting element disposed on the substrate, and a light receiving element disposed on the substrate; and

an optical receptacle, disposed above the photoelectric conversion device, for optically coupling the light emitting element and the light receiving element to an end surface of an optical transmission body when the optical receptacle is connected to the optical transmission body,

the optical receptacle has:

a first optical surface on which the signal light emitted from the light emitting element is incident;

a second optical surface for allowing the signal light incident from the first optical surface to exit to an end surface of the optical transmission body and allowing the received light exiting from the optical transmission body to enter;

a transmission/reflection unit for reflecting the signal light incident from the first optical surface toward the second optical surface and transmitting the received light incident from the second optical surface toward the light receiving element;

a recess for accommodating the transflective portion; and

a third optical surface for emitting the received light transmitted by the transmission/reflection unit to the light receiving element,

fixing the transflective portion to an inner surface of the recess at a position out of an optical path of the signal light in the transflective portion,

an optical path within the recess is inclined with respect to an optical path between the first optical surface and the recess when viewed along a normal direction of the substrate.

4. The light module of claim 3,

the optical module further includes a reflecting surface disposed on an optical path between the concave portion and the second optical surface, and configured to reflect the received light transmitted through the concave portion toward the second optical surface.

5. The light module according to any one of claims 1 to 4,

the transflective portion is disposed perpendicular to an optical path in the recess in a cross section along the surface of the substrate.

Technical Field

The present invention relates to an optical module.

Background

Conventionally, in optical communication using an optical transmission medium such as an optical fiber or an optical waveguide, an optical module (optical transmission module) including a light emitting element such as a light emitting diode and a light receiving element such as a photodetector is used. The optical module has an optical receptacle (optical member) for allowing light including communication information emitted from the light emitting element to enter an end surface of the optical transmission member and allowing light including communication information emitted from the optical transmission member to enter an end surface of the light receiving element (see, for example, patent document 1).

For example, patent document 1 describes an optical transmission module including: an optical element unit including a transmitting optical element and a receiving optical element, an optical fiber, and an optical component. The optical component causes an optical signal from the transmitting optical element to enter the optical fiber, or causes an optical signal from the optical fiber to enter the receiving optical element. The optical component includes: a transmission lens disposed opposite to the transmission optical element; a lens for an optical fiber disposed opposite to the optical fiber; a receiving lens disposed opposite to the receiving optical element; an optical filter that reflects signal light incident from the transmission lens toward the optical fiber lens or transmits received light incident from the optical fiber lens; and a reflecting surface for reflecting the received light transmitted through the filter toward the receiving lens. The optical filter is disposed facing the optical filter mounting surface of the optical filter mounting portion, and is fixed by filling the optical filter mounting portion with a transparent adhesive.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2009-251375

Disclosure of Invention

Problems to be solved by the invention

However, in the optical transmission module described in patent document 1, since the adhesive is located on the optical path of the signal light or the received light, the optical path of the signal light or the received light changes depending on the refractive index of the cured adhesive, the cured state of the adhesive, bubbles mixed in the cured adhesive, and the like. This may reduce the optical coupling efficiency of the signal light or the received light.

An object of the present invention is to provide an optical module capable of bidirectional optical communication while maintaining optical coupling efficiency of signal light and received light.

Means for solving the problems

An optical module of the present invention includes: a photoelectric conversion device having a substrate, a light emitting element disposed on the substrate, and a light receiving element disposed on the substrate; and an optical receptacle disposed on the photoelectric conversion device and optically coupling the light emitting element and the light receiving element to an end surface of an optical transmission body when the optical receptacle is connected to the optical transmission body, the optical receptacle including: a first optical surface on which the signal light emitted from the light emitting element is incident; a second optical surface for allowing the signal light incident from the first optical surface to exit to an end surface of the optical transmission body and allowing the received light exiting from the optical transmission body to enter; a transmission/reflection unit that transmits the signal light incident from the first optical surface to the second optical surface and reflects the received light incident from the second optical surface to the light receiving element; a recess for accommodating the transflective portion; and a third optical surface for emitting the received light reflected by the transflective portion toward the light receiving element, wherein the transflective portion is fixed to an inner surface of the recess at a position other than an optical path of the signal light in the transflective portion, and the optical path in the recess is inclined with respect to an optical path between the second optical surface and the recess when viewed along a normal direction of the substrate.

Another optical module of the present invention includes: a photoelectric conversion device having a substrate, a light emitting element disposed on the substrate, and a light receiving element disposed on the substrate; and an optical receptacle disposed on the photoelectric conversion device and optically coupling the light emitting element and the light receiving element to an end surface of an optical transmission body when the optical receptacle is connected to the optical transmission body, the optical receptacle including: a first optical surface on which the signal light emitted from the light emitting element is incident; a second optical surface for allowing the signal light incident from the first optical surface to exit to an end surface of the optical transmission body and allowing the received light exiting from the optical transmission body to enter; a transmission/reflection unit for reflecting the signal light incident from the first optical surface toward the second optical surface and transmitting the received light incident from the second optical surface toward the light receiving element; a recess for accommodating the transflective portion; and a third optical surface for emitting the received light transmitted by the transflective portion toward the light receiving element, wherein the transflective portion is fixed to an inner surface of the recess at a position other than an optical path of the signal light in the transflective portion, and the optical path in the recess is inclined with respect to an optical path between the first optical surface and the recess when viewed along a normal direction of the substrate.

Effects of the invention

According to the present invention, it is possible to provide an optical module capable of bidirectional optical communication while maintaining optical coupling efficiency of signal light and received light.

Drawings

Fig. 1 is a sectional view of an optical module according to embodiment 1.

Fig. 2 is a plan view of the optical module according to embodiment 1.

Fig. 3A and 3B are diagrams for explaining the inclination angle of the recess.

Fig. 4A to 4D are diagrams showing the structure of the optical module according to embodiment 2.

Fig. 5A to 5D are another diagrams showing the structure of the optical module according to embodiment 2.

Detailed Description

An embodiment of the present invention will be described in detail below with reference to the drawings.

[ embodiment 1]

(Structure of optical Module)

Fig. 1 is a sectional view of an optical module 100 according to embodiment 1. Fig. 2 is a plan view of the optical module 100 according to the present embodiment. Fig. 3A is a diagram for explaining an inclination angle of the recess, and fig. 3B is a diagram for explaining an inclination angle of the transmitting and reflecting portion 143 with respect to an optical axis of the received light Lr passing through the recess 144 in a cross section parallel to the substrate 121. Fig. 1 shows an optical path in the optical module 100. Fig. 3 shows an optical axis of an optical path in the optical module 100. In fig. 1, hatching of the cross section of the optical receptacle 140 is omitted to show the optical path in the optical receptacle 140.

As shown in fig. 1 and 2, the optical module 100 includes: a substrate-mounted photoelectric conversion device 120 including a light emitting element 122 and a light receiving element 123, and an optical receptacle 140. The optical module 100 is an optical module for bidirectional optical communication, and the optical module 100 is used by coupling (hereinafter, also referred to as "connecting") an optical transmission body 160 to an optical receptacle 140 via a ferrule 162. The kind of the optical transports 160 is not particularly limited and includes optical fibers, optical waveguides, and the like. In the present embodiment, the optical transport 160 is an optical fiber. The fiber may be either single mode or multi-mode. The number of the light transports 160 is not particularly limited. In the present embodiment, the number of the optical transports 160 is one.

The photoelectric conversion device 120 includes a substrate 121, a light emitting element 122, and a light receiving element 123.

The substrate 121 is, for example, a glass composite substrate, an epoxy glass substrate, a flexible substrate, or the like. A light emitting element 122 and a light receiving element 123 are disposed on the substrate 121.

The light emitting element 122 is disposed on the substrate 121, and emits light in a direction perpendicular to the substrate 121. The light Emitting element is, for example, a light Emitting diode or a Vertical Cavity Surface Emitting Laser (VCSEL). The number of the light emitting elements 122 is not particularly limited. In this embodiment, the number of the light emitting elements 122 is one. In addition, the position of the light emitting element 122 is not particularly limited. In addition, the optical axis in the concave portion 144 of the signal light Ls emitted from the light emitting element 122 may be inclined with respect to the end surface 125 of the optical transmission body 160 from the viewpoint of preventing the reflected light from the optical transmission body 160 from returning to the light emitting element 122.

The light receiving element 123 is disposed on the substrate 121 and receives the received light Lr emitted from the optical transmission body 160. The light receiving element 123 is, for example, a photodetector. The number of the light receiving elements 123 is not particularly limited, and is, for example, the same as the number of the light emitting elements 122. In the present embodiment, the number of the light receiving elements 123 is one.

The optical receptacle 140 is disposed on the substrate 121 of the photoelectric conversion device 120. The optical receptacle 140 is disposed between the photoelectric conversion device 120 and the optical transmission body 160, and optically couples the light-emitting surface 124 of the light-emitting element 122 to the end surface 125 of the optical transmission body 160, and optically couples the end surface 125 of the optical transmission body 160 to the light-receiving surface 126 of the light-receiving element 123. Next, the structure of the optical receptacle 140 will be described in detail.

(Structure of optical receptacle)

The optical receptacle 140 has optical transparency, and emits the signal light Ls emitted from the light-emitting surface 124 of the light-emitting element 122 toward the end surface 125 of the optical transmission body 160. The optical receptacle 140 emits a part of the received light Lr emitted from the end surface 125 of the optical transmission member 160 to the light receiving surface 126 of the light receiving element 123. The optical receptacle 140 has: a first optical surface 141, a reflective surface 142, a transflective portion 143, a recess 144, a second optical surface 145, and a third optical surface 146.

The optical receptacle 140 is formed using a material having optical transparency to light of a wavelength used in optical communication. Examples of such materials include: a transparent resin such as Polyetherimide (PEI) or cyclic olefin resin. In addition, the optical receptacle 140 is manufactured by, for example, injection molding.

The first optical surface 141 is an optical surface that refracts the signal light Ls emitted from the light emitting element 122 and then enters the optical receptacle 140. The first optical surface 141 can convert the signal light Ls emitted from the light emitting element 122 into collimated light, convergent light, or diffused light. In the present embodiment, the first optical surface 141 converts the signal light Ls emitted from the light emitting element 122 into collimated light. In the present embodiment, the first optical surface 141 has a convex lens surface that is convex toward the light emitting element 122. The first optical surface 141 has a circular shape in plan view. Preferably, the central axis of the first optical surface 141 is perpendicular to the light emitting surface 124 of the light emitting element 122. Further, it is preferable that the central axis of the first optical surface 141 coincides with the optical axis of the signal light Ls emitted from the light emitting element 122.

The reflection surface 142 is an inclined surface formed on the top surface side of the optical receptacle 140, and is disposed on the optical path between the first optical surface 141 and the recess 144 (the transmissive/reflective portion 143). The reflection surface 142 internally reflects the light (the signal light Ls emitted from the light emitting element 122) incident from the first optical surface 141 toward the concave portion 144 (the transmitting and reflecting portion 143). The reflection surface 142 is inclined in such a manner as to gradually approach the light transmissive body 160 as approaching from the bottom surface to the top surface of the optical receptacle 140. In the present embodiment, the reflecting surface 142 is inclined at an angle of 45 ° with respect to the optical axis of the signal light Ls incident from the first optical surface 141. The signal light Ls incident from the first optical surface 141 is internally incident to the reflecting surface 142 at an incident angle larger than the critical angle. Thereby, the reflecting surface 142 totally reflects the incident signal light Ls in the direction along the surface of the substrate 121.

The transmitting/reflecting portion 143 transmits the signal light Ls reflected by the reflecting surface 142 to the second optical surface 145, and reflects at least a part of the received light Lr incident from the second optical surface 145 to the light receiving element 123. The structure of the transflective portion 143 is not particularly limited as long as the above-described function can be exerted. In the present embodiment, the transmitting/reflecting portion 143 is a wavelength separation filter that transmits light having the wavelength of the signal light Ls and reflects light having the wavelength of the received light Lr. In the present embodiment, the transflective portion 143 is inclined so as to gradually approach the second optical surface 145 (the light transmissive body 160) as approaching from the bottom surface to the top surface of the optical receptacle 140. When the light receptacle 140 is viewed from the side (when viewed from the direction along the surface of the substrate 121), the angle of inclination of the transmitting and reflecting portion 143 with respect to the optical axis of the received light Lr incident from the second optical surface 145 is 45 °.

The transflective portion 143 is fixed to an inner surface of the recess 144. The transmitting/reflecting portion 143 is fixed to the concave portion 144 at a position other than the optical path of the signal light Ls in the transmitting/reflecting portion 143. A method of fixing the transmissive and reflective part 143 to the concave part 144 is not particularly limited. In the present embodiment, the end portions of the first side surface 144a of the concave portion 144 and the first side surface 144a of the transmissive and reflective portion 143, and the end portions of the second side surface 144b of the concave portion 144 and the second side surface 144b of the transmissive and reflective portion 143 are fixed by an adhesive. In the present embodiment, the outer shape of the transmitting/reflecting portion 143 is processed such that, when the transmitting/reflecting portion 143 is disposed in the recess 144, the transmitting/reflecting portion 143 is inclined by 45 ° with respect to the optical axis of the received light Lr when the optical receptacle 140 is viewed from the side (when viewed from the direction along the surface of the substrate 121).

As shown in fig. 3B, in a cross section parallel to the surface of the substrate 121, the transmitting/reflecting portion 143 is inclined so as to be perpendicular to the optical axis of the received light Lr (signal light Ls) passing through the inside of the recess 144.

The recess 144 accommodates the transflective portion 143 therein. The shape of the recess 144 is not particularly limited as long as the transflective portion 143 can be accommodated. In the present embodiment, the recess 144 has a substantially rectangular parallelepiped shape having a first side surface 144a and a second side surface 144 b.

The first side surface 144a is an inner surface on the reflecting surface 142 side. The shape of the first side surface 144a is not particularly limited. In the present embodiment, the first side surface 144a is a plane. The smaller angle θ 1 of the angles formed by the signal light Ls incident on the first side surface 144a and the first side surface 144a when the optical receptacle 140 is viewed from above is not particularly limited. The angle θ 1 is preferably 70 ° to 88 °, and more preferably 55 ° to 86 °. In the case where the angle θ 1 is smaller than 70 °, there is a possibility that a part of the light may be reflected. On the other hand, in the case where the angle θ 1 exceeds 88 °, there is a possibility that the reflected light from the light transmission body 160 returns to the light emitting element 122, thereby generating noise in the signal light Ls.

The second side surface 144b is an inner surface on the second optical surface 145 side. The shape of the second side surface 144b is not particularly limited. In the present embodiment, the second side surface 144b is a plane. The smaller angle θ 2 of the angles formed by the second side surface 144b and the signal light Ls incident from the second side surface 144b when the optical receptacle 140 is viewed from above is not particularly limited. The angle θ 2 is 55 ° to 88 °, more preferably 75 ° to 86 °, and more preferably an angle equal to θ 1. In the case where the angle θ 2 is less than 70 °, there is a possibility that a part of the light may be reflected. On the other hand, in the case where the angle θ 2 exceeds 88 °, there is a possibility that the reflected light from the light transmission body 160 returns to the light emitting element 122, thereby generating noise in the signal light Ls. In other words, the second side surface 144b is inclined with respect to the received light Lr incident from the second optical surface 145.

Preferably, the first side 144a is parallel to the second side 144b when the light socket 140 is viewed from above. That is, the angle θ 1 is preferably the same angle as the angle θ 2. If the first side surface 144a and the second side surface 144b are parallel, the light beams before and after passing through the recess 144 (the light beam before being emitted from the first side surface 144a into the recess 144 and the light beam re-entering the optical receptacle 140 from the second side surface 144 b) are parallel, and thus the design of the optical receptacle 140 is easy (see the dotted line in fig. 3).

The second optical surface 145 is an optical surface that allows the signal light Ls transmitted through the transmitting and reflecting portion 143 to exit to the end surface 125 of the optical transmission body 160, and allows the received light Lr exiting from the optical transmission body 160 to be refracted and enter the inside of the optical receptacle 140. The second optical surface 145 can convert the received light Lr emitted from the light transport 160 into collimated light, convergent light, or diffused light. In the present embodiment, the second optical surface 145 converts the received light Lr emitted from the light transmitting body 160 into collimated light. In the present embodiment, the second optical surface 145 is disposed on a side surface of the optical receptacle 140 so as to face the end surface 125 of the optical transmission body 160. The second optical surface 145 is a convex lens surface having a convex shape toward the end surface 125 of the light transmission body 160. Thereby, the signal light Ls incident from the first optical surface 141 and transmitted from the transmitting/reflecting portion 143 can be condensed and efficiently connected to the end surface 125 of the optical transmission body 160.

The third optical surface 146 is disposed on the bottom surface side of the optical receptacle 140 so as to face the light receiving element 123. In the present embodiment, the third optical surface 146 is a convex lens surface that is convex toward the light receiving element 123. The third optical surface 146 converges the received light Lr reflected by the transmitting/reflecting portion 143 and emits the converged light Lr to the light receiving element 123. This enables the received light Lr to be efficiently coupled to the light-receiving element 123. The central axis of the third optical surface 146 may be perpendicular to the light receiving surface 126 (substrate 121) of the light receiving element 123, or may be inclined with respect to the light receiving surface 126 (substrate 121) of the light receiving element 123.

(optical path in optical socket)

Here, the optical path in the optical receptacle 140 will be described. The signal light Ls emitted from the light emitting element 122 enters the light receptacle 140 through the first optical surface 141. The signal light Ls incident on the first optical surface 141 is internally reflected by the reflection surface 142 toward the concave portion 144 (the transmitting and reflecting portion 143). The signal light Ls internally reflected by the reflection surface 142 is transmitted through the concave portion 144 and the transmission/reflection portion 143, and then is emitted from the second optical surface 145 toward the end surface 125 of the optical transmission body 160. At this time, since the transmitting and reflecting portion 143 is fixed to the inside of the concave portion 144 at a position other than the optical path of the signal light Ls in the transmitting and reflecting portion 143, the progress of the signal light Ls is not hindered by a fixing means (e.g., an adhesive) of the transmitting and reflecting portion 143. The signal light Ls reflected by the reflecting surface 142 is refracted by the first side surface 144a and then emitted into the concave portion 144. Then, the light is transmitted through the transflective portion 143 and refracted by the second side surface 144b, and then enters the inside of the optical receptacle 140 again.

On the other hand, the received light Lr emitted from the optical transport 160 is incident on the inside of the optical receptacle 140 from the second optical surface 145. A part of the received light Lr incident from the second optical surface 145 is transmitted from the second side surface 144b of the concave portion 144 and reflected by the transmitting and reflecting portion 143 toward the third optical surface 146. In addition, another part of the received light Lr incident from the second optical surface 145 is reflected by the second side surface 144b of the concave portion 144. At this time, when looking down the optical path between the reflecting surface 142 and the second optical surface 145, the optical path inside the concave portion 144 is inclined with respect to the optical path between the second optical surface 145 and the concave portion 144. That is, the second side surface 144b is inclined with respect to the received light Lr incident from the second optical surface 145 when viewed along the normal direction of the substrate 121. Therefore, the received light Lr is not reflected toward the third optical surface 146 (light transport 160). The received light Lr reflected by the transmitting/reflecting portion 143 is emitted from the third optical surface 146 and reaches the light receiving element 123.

(Effect)

As described above, in the optical module 100 of the present embodiment, since the transflective portion is fixed inside the concave portion 144 at a position other than the optical path of the signal light Ls in the transflective portion 143, the optical coupling efficiency between the signal light Ls and the received light Lr can be maintained regardless of the fixing method. In the optical module 100 of the present embodiment, the second side surface 144b is inclined with respect to the received light Lr incident from the second optical surface 145, and therefore the received light Lr is not reflected toward the second optical surface 145 (the optical transmission body 160).

In addition, the optical receptacle 140 may not have the reflective surface 142. In this case, the light emitting element 122 and the first optical surface 141 are disposed on the side of the optical receptacle 140.

[ embodiment 2]

The optical receptacle 240 of the optical module according to embodiment 2 is the same as the optical receptacle 140 of the optical module according to embodiment 1 except that it is a lens array type optical receptacle corresponding to multichannel transmission. Therefore, the same components as those in embodiment 1 are denoted by the same reference numerals and their description is omitted.

(Structure of optical receptacle)

Fig. 4A to 4D are diagrams showing the structure of the optical receptacle 240 without the transmissive and reflective portion 143, and fig. 5A to 5D are diagrams showing the structure of the optical receptacle 240 with the transmissive and reflective portion 143. Fig. 4A and 5A are plan views of the optical receptacle 240 of the optical module according to embodiment 2, fig. 4B and 5B are bottom views, fig. 4C and 5C are right views, and fig. 4D and 5D are cross-sectional views taken along line a-a shown in fig. 4A and 5A.

As shown in fig. 4A to 4D and fig. 5A to 5D, the optical receptacle 240 of the optical module according to embodiment 2 includes: the optical member includes a plurality of first optical surfaces 141, a reflective surface 142, a transflective portion 143, a plurality of concave portions 144, a plurality of second optical surfaces 145, and a plurality of third optical surfaces 146. In the present embodiment, the plurality of optical transmitters 160 are mounted to the optical receptacle by a known mounting means while being housed in the multi-core integrated connector.

The number of the light transmitting body 160, the light emitting element 122, and the light receiving element 123 is not particularly limited, and may be plural. In the present embodiment, the number of the light transmitting member 160, the number of the light emitting element 122, and the number of the light receiving element 123 are four, respectively.

(Effect)

As described above, the optical module of the present embodiment has the same effects as the optical module of embodiment 1.

The present application claims priority based on japanese patent application No. 2018-164292, filed on 9/3 in 2018. The contents described in the specification and drawings are all incorporated in the specification of the present application.

Industrial applicability

The optical module of the present invention is useful for optical communication using an optical transmission medium, for example.

Description of the reference numerals

100 optical module

120 photoelectric conversion device

121 substrate

122 light emitting element

123 light-receiving element

124 light emitting face

125 end face

126 light receiving surface

140. 240 optical socket

141 first optical surface

142 reflective surface

143 transmissive and reflective part

144 recess

144a first side surface

144b second side

145 second optical surface

146 third optical surface

160 optical transmission body

162 sleeve

Lr receives light

Ls signal light