JP2012032509A - Lens array and optical module equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To materialize multichannel optical communication with a connector in which a plurality of optical fibers are aligned in four lines, without generating interference or stray light, by a simple structure.SOLUTION: In two lens array bodies 21-1, 21-2, a total reflecting surface 24a, a transparent surface 25a, a transparent surface 25b, and a total reflection surface 25c are formed. The total reflecting surface 24a totally reflects each laser beam La-1, La-2. The transparent surface 25a and the transparent surface 25b make each laser beam La-1, La-2 pass through. The total reflecting surface 25c totally reflects each laser light Lc-1, Lb-2. Consequently, the lens array bodies 21-1, 21-2 optically unite an optical fiber and a photoelectric conversion element, without making lights paths of the laser beams intersect each other.

Description

  The present invention relates to a lens array and an optical module including the same, and more particularly to a lens array suitable for executing multi-channel optical communication and an optical module including the same.

  In recent years, the necessity for high-speed transmission of signals within a system apparatus or between apparatuses has increased rapidly, and development of optical interconnection has been activated. Optical interconnection is a general term for technologies that convert electrical signals into optical signals and transmit light including communication information via an optical fiber or the like.

  In such an optical interconnection, a multi-channel optical communication is realized by connecting a connector in which a plurality of optical fibers are arranged and arranged to an optical module.

  In order to make the optical module for multi-channel optical communication compact, a plurality of photoelectric conversion elements (light-emitting elements and light-receiving elements) are arranged on the substrate so as to have an optical axis in the normal direction of the substrate surface. There is a type in which a connector in which the same number of optical fibers as the photoelectric conversion elements are arranged and arranged so as to have an optical axis in a direction orthogonal to the optical axis of the photoelectric conversion elements is attached to the lens array.

  Furthermore, in recent years, in order to realize higher-speed signal transmission, a lens array for realizing multichannel optical communication by attaching a connector in which a plurality of optical fibers are arranged in two rows and an optical module including the same are being developed. (For example, patent document 1, FIG. 23A, FIG. 23B).

  In the lens array (optical member 22) of Patent Document 1 (FIGS. 23A and 23B), the light emitted from each light emitting element (VCSEL30) is incident from the first lens (collimator lens 70), and the second lens. Light is emitted from the (condensing lens 75) toward the end face of each optical fiber (10). Further, the lens array (optical member 22) of Patent Document 1 (FIGS. 23A and 23B) receives light emitted from each optical fiber (10) from a third lens (collimator lens 76), and the fourth lens array (optical member 22). The light is emitted from each lens (condensing lens 77) toward each light receiving element (PD32).

JP 2006-344915 A

  However, in the technique disclosed in Patent Document 1, the optical path from the first lens to the second lens and the optical path from the third lens to the fourth lens intersect in the lens array. May interfere with each other, causing interference and stray light.

  In addition, a lens array and an optical module equipped with the lens array for realizing multichannel optical communication by attaching a connector in which a plurality of optical fibers are arranged in four rows have been not developed so far. Note that if the above-described conventional technique is used to achieve multi-channel optical communication by arranging a plurality of optical fibers in four rows, two connectors are required, and the optical module becomes large.

  The present invention has been made in view of the above points, and realizes multi-channel optical communication with a connector in which a plurality of optical fibers are arranged in four rows without causing interference or stray light with a compact configuration. An object of the present invention is to provide a lens array that can be used and an optical module including the same.

  The lens array of the present invention is attached to a first substrate and a second substrate facing the first substrate, and 4 rows × n optical fibers (n is a number per row and a plurality). Are arranged so that the optical axes of the optical fibers are parallel to the first substrate surface and the second substrate surface, and are arranged in two rows on the first substrate. 2 × n first photoelectric conversion element groups having an optical axis in the normal direction of the substrate surface, and two rows arranged on the second substrate, and light in the normal direction of the second substrate surface A lens array for optically coupling 2 × n second photoelectric conversion element groups having axes and the 4 × n optical fibers, wherein the lens array is a first lens array body. And a second lens array body, wherein the first and second lens array bodies N first lenses provided at positions opposed to the end faces of the optical fibers in the first row, which are rows far from the conversion elements, and the photoelectric elements in the first row, which are rows far from the optical fibers. N second lenses provided at positions facing the conversion elements, and n third lenses provided at positions facing the end faces of the optical fibers in the second row, which is a row closer to the photoelectric conversion elements. Lens, n fourth lenses provided at positions facing the respective photoelectric conversion elements in the second row, which is a row closer to the optical fiber, and the photoelectric conversion elements in the first row or the first row. A first reflecting surface that changes the traveling direction of light emitted from the end face of the optical fiber in the row and passes through the first optical path between the first lens and the second lens; and the photoelectric in the second row The third element is emitted from the end face of the conversion element or the second row of optical fibers. A second reflecting surface that changes a traveling direction of light passing through a second optical path between the lens and the fourth lens, and the first reflecting surface does not interfere with the second optical path. The second reflection surface is provided at a position that does not interfere with the first optical path.

  According to the present invention, 4 × n optical fibers and 4 × n photoelectric conversion elements whose optical axes are orthogonal to each other can be optically coupled without the optical paths intersecting each other. Therefore, multi-channel optical communication can be realized with a connector having a plurality of optical fibers arranged in four rows without causing interference or stray light with a compact configuration.

The block diagram which shows the structure of the optical module which concerns on Embodiment 1 of this invention with the side surface longitudinal cross-sectional view of a lens array 1 is a partial configuration diagram showing a partial configuration of the optical module of FIG. 1 together with a side longitudinal sectional view of a lens array body. The figure which shows the lens array main body of FIG. The figure which shows the coupling | bonding state of the lens array and semiconductor substrate of the optical module of FIG. The figure which shows the variation of the lens array main body of the optical module which concerns on Embodiment 1 of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, multi-channel bidirectional communication with 48 cores (= 12 cores × 4 columns) will be described as an example.

(Embodiment 1)
[Configuration of optical module]
FIG. 1 is a configuration diagram showing a configuration of an optical module according to Embodiment 1 of the present invention, together with a side longitudinal sectional view of a lens array. FIG. 2 is a partial configuration diagram showing a partial configuration of the optical module in FIG. 1 together with a side longitudinal sectional view of the lens array body. FIG. 3 is a diagram showing the lens array body of FIG. 3A is a front view of the lens array body, FIG. 3B is a plan view of the lens array body, FIG. 3C is a bottom view of the lens array body, and FIG. 3D is a right side of the lens array body. FIG.

  As shown in FIGS. 1 and 2, the optical module 1 is mainly composed of photoelectric conversion devices 10-1 and 10-2, a lens array 20, and an optical fiber cable 40.

[Configuration of photoelectric conversion device]
The photoelectric conversion device 10-1 is a device that converts an electrical signal into an optical signal, and includes two rows (12 in each row) of light emitting elements (laser sources) 11a and 11b. The light emitting elements 11a and 11b are arranged on the attachment surface 14-1 of the semiconductor substrate 13-1 on the transmission side at regular intervals in the direction perpendicular to the paper surface in FIG. 1, and are perpendicular to the attachment surface 14-1 ( Laser beams La-1 and Lb-1 are emitted (emitted) in the downward direction in FIG. A vertical cavity surface emitting laser (VCSEL) is used for the plurality of light emitting elements 11a and 11b.

  The photoelectric conversion device 10-2 is a device that converts an optical signal into an electrical signal, and includes two rows (12 in each row) of light receiving elements (PD: Photo Detector) 12a and 12b. The light receiving elements 12a and 12b are arranged on the mounting surface 14-2 of the semiconductor substrate 13-2 on the receiving side at regular intervals in the direction perpendicular to the paper surface in FIG. 1, and on the light receiving surface parallel to the mounting surface 14-2. The laser beams La-2 and Lb-2 emitted from the lens array 20 are received.

[Configuration of optical fiber cable]
The optical fiber cable 40 includes four rows (12 in each row) of optical fibers 40a-1, 40b-1, 40a-2, and 40b-2. An MT connector (mechanically transferable splicing connector) 41 is attached to the tip of the optical fiber cable 40. The MT connector 41 is a multi-core collective connector that is attached to the tip of an optical fiber core. In this embodiment, an optical transmission body such as an optical waveguide can be attached instead of the MT connector with an optical fiber.

  The MT connector 41 has two fitting holes (not shown). The optical fiber cable 40 can be attached to the lens array 20 by fitting the two fitting holes and the two fitting pins 26 of the lens array 20 respectively.

[Configuration of lens array]
The lens array 20 includes two lens array bodies 21-1 and 21-2 of the same type. The lens array body 21-1 is mounted on the mounting surface 14-1 of the semiconductor substrate 13-1, and optically couples the optical fibers 40a-1 and 40b-1 and the corresponding light emitting elements 11a and 11b. Combine. The lens array body 21-2 optically couples the optical fibers 40a-2 and 40b-2 and the corresponding light receiving elements 12a and 12b on the mounting surface 14-2 of the semiconductor substrate 13-2. Let

  The lens array main bodies 21-1 and 21-2 are substantially rectangular parallelepiped, and have optical transparency such as PEI (polyetherimide), PMMA (polymethyl methacrylate), PC (polycarbonate), and EP (epoxy resin). It is formed with the resin material which has, or transparent glass.

  Since the lens array body 21-1 is the same type as the lens array body 21-2, the lens array body 21-2 will be described below with reference to FIGS. 2 and 3, and the lens array body 21-1 will be described. Is omitted.

  In the lens array main body 21-2, the bottom surface 22a is parallel to the outer peripheral surface 21a from the outer peripheral surface 21a (the lower end surface in FIG. 2) facing the photoelectric conversion device 10-2 to the outer peripheral surface 21d (the right end surface in FIG. 2). A notch 22 is formed. The lens array body 21-2 has a bottom surface 23a extending from the outer peripheral surface 21b (left end surface in FIG. 2) facing the end surfaces of the optical fibers 40a-2 and 40b-2 to the outer peripheral surface 21c (upper end surface in FIG. 2). A cutout 23 parallel to the outer peripheral surface 21b is formed. The lens array body 21-2 has a notch 24 formed from the outer peripheral surface 21c to the outer peripheral surface 21d. Further, the lens array body 21-2 is formed with a recess 25 at the center of the outer peripheral surface 21c. An alignment mark 22b for alignment may be provided on the bottom surface 22a.

  The lens array main body 21-2 has two convex portions 26a and 26b at both ends of the outer peripheral surface 21b. The convex portions 26a and 26b have a semi-cylindrical shape, and the plane portion is flush with the outer peripheral surface 21c. The convex portion 26a of the lens array main body 21-1 and the convex portion 26b of the lens array main body 21-2 are combined to form one fitting pin 26. Similarly, the convex portion 26b of the lens array main body 21-1 and the convex portion 26a of the lens array main body 21-2 are combined to form the other fitting pin 26 (see FIG. 4). In addition, you may give a spherical surface process or a chamfering process to the front-end | tip of convex part 26a, 26b.

  The lens array main body 21-2 is formed with two attachment holes 27a and 27b penetrating to the outer peripheral surface 21c at both ends of the outer peripheral surface 21a. The mounting holes 27a and 27b are used for mounting the lens array body 21-2 on the mounting surface 14-2 of the semiconductor substrate 13-2.

  The lens array main body 21-2 has the same number (12) of circular first lenses 31 (convex lenses) as the optical fibers 40a-2 on the bottom surface 23a. Each first lens 31 is aligned and disposed at a position facing the end face of each optical fiber 40a-2. Each first lens 31 refracts the laser light La-2 emitted from the corresponding end face of each optical fiber 40a-2 so as to be focused light and then enters the inside of the lens array body 21-2. Make it progress. Each first lens 31 of the lens array body 21-1 collects each laser beam La-1 that has traveled the optical path inside the lens array body 21-1 on the end face of each optical fiber 40a-1. The light is refracted so as to be emitted, and emitted toward the end face of each corresponding optical fiber 40a-1 (see FIG. 1).

  The lens array main body 21-2 has the same number (12) of circular second lenses 32 (convex lenses) as the light receiving elements 12a on the bottom surface 22a. Each second lens 32 is aligned and disposed at a position facing each light receiving element 12a. Each second lens 32 receives each laser beam La-2 that has entered the corresponding first lens 31 and traveled through the optical path inside the lens array body 21-2 to the light receiving portion of the light receiving element 12a. The light is refracted so as to be focused light to be irradiated, and is emitted toward the corresponding light receiving element 12a. Each second lens 32 of the lens array body 21-1 refracts the laser light La-1 emitted from each corresponding light emitting element 11a so as to become a focused light, and then the lens array body 21-. 1 (see FIG. 1).

  The lens array main body 21-2 has the same number (12) of circular third lenses 33 (convex lenses) as the optical fibers 40b-2 on the bottom surface 23a. Each of the third lenses 33 is aligned at a position that is closer to the light receiving elements 12a and 12b than the corresponding first lens 31 and that faces the end face of each of the optical fibers 40b-2. Each third lens 33 refracts the laser light Lb-2 emitted from the corresponding end face of each optical fiber 40b-2 so as to be parallel light and then enters the lens array main body 21-2. Make it progress. Each third lens 33 of the lens array main body 21-1 collects each laser beam Lb-1 traveling in the optical path inside the lens array main body 21-1 on the end face of each optical fiber 40b-1. The light is refracted so as to be emitted and emitted toward the end face of each corresponding optical fiber 40b-1 (see FIG. 1).

  The lens array main body 21-2 has the same number (12) of circular fourth lenses 34 (convex lenses) as the light receiving elements 12b on the bottom surface 22a. Each fourth lens 34 is arranged at a position closer to the optical fiber than each corresponding second lens 32 and facing each light receiving element 12b. Each fourth lens 34 receives each laser beam Lb-2 that has entered the corresponding third lens 33 and traveled through the optical path inside the lens array body 21-2 to the light receiving portion of the light receiving element 12b. The light is refracted so as to be focused light to be irradiated, and is emitted toward the corresponding light receiving element 12b. Each fourth lens 34 of the lens array body 21-1 refracts the laser light Lb-1 emitted from each corresponding light emitting element 11b so as to become parallel light, and then the lens array body 21-. 1 (see FIG. 1).

  A flat total reflection surface 24 a is formed in the notch 24. The angle of the total reflection surface 24a is preferably set based on the material (refractive index) of the lens array body 21-2. For example, when the lens array main body 21-2 is formed of PEI, the angle of the total reflection surface 24a is 47 ° clockwise in FIG. 2 when the horizontal direction in FIG. 2 is used as a reference (0 °). The total reflection surface 24a is provided at a position where it does not interfere with the optical path of the laser beam Lb-2, and totally reflects each laser beam La-2 emitted from the first lens 31. The total reflection surface 24a may be coated with a reflection film made of Au, Ag, Al, or the like.

  The cutout 24 is formed with a flat surface 24b that connects the lower end side of the total reflection surface 24a and the outer peripheral surface 21d in order to form the total reflection surface 24a.

  The recess 25 has a flat transmission surface 25a that forms part of the side surface of the recess 25, a flat transmission surface 25b that forms part of the side surface of the recess 25, and a flat surface that forms part of the bottom surface of the recess 25. A total reflection surface 25c is formed.

  In the recess 25, a relief surface 25d is formed between the transmission surface 25b and the total reflection surface 25c so that the laser light L1 transmitted through the transmission surface 25a does not strike the total reflection surface 25c.

  The transmitting surface 25a has an inclination (about 3 °) such that the upper end side and the lower end side in FIG. Formed. The transmitting surface 25a refracts and transmits each incident laser beam La-2 according to Snell's law.

  The transmission surface 25b has an inclination (about 3 °) such that the upper end side and the lower end side in FIG. Formed. The transmission surface 25b refracts and transmits each incident laser beam La-2 according to Snell's law.

  When the horizontal direction in FIG. 2 is a reference (0 °), the angle of the total reflection surface 25c is 45 ° in the clockwise direction in FIG. The total reflection surface 25c is provided at a position that does not interfere with the optical path of the laser beam La-2 and closer to the third lens 33 and the fourth lens 34 than the total reflection surface 24a. Each emitted laser beam Lb-2 is totally reflected. The total reflection surface 25c may be coated with a reflection film made of Au, Ag, Al, or the like.

[Combination of lens array and semiconductor substrate]
Next, the coupling between the lens array 20 and the semiconductor substrates 13-1 and 13-2 will be described. FIG. 4 is a diagram illustrating a coupling state between the lens array 20 illustrated in FIG. 1 and the semiconductor substrates 13-1 and 13-2. 4A is a front view of the lens array 20 and the semiconductor substrates 13-1 and 13-2, and FIG. 4B is a right side view of the lens array 20 and the semiconductor substrates 13-1 and 13-2.

  Through holes 15 a and 15 b are provided in the semiconductor substrates 13-1 and 13-2. The inner diameters of the through holes 15a and 15b are substantially the same as the inner diameters of the mounting holes 27a and 27b. The interval between the through hole 15a and the through hole 15b is the same as the interval between the attachment hole 27a and the attachment hole 27b.

  In order to couple the lens array 20 and the semiconductor substrates 13-1 and 13-2, first, the lens array body 21-2, the lens array body 21-1 and the semiconductor substrate 13-1 are placed on the semiconductor substrate 13-2. Put in this order. At this time, the outer peripheral surface 21c of the lens array main body 21-2 and the outer peripheral surface 21c of the lens array main body 21-1 face each other, and the convex portions 26a and 26b of the lens array main bodies 21-1 and 21-2 are in the same direction (FIG. 4 ( Turn to the left of b).

  Then, the positions of the mounting holes 27a, 27b of the lens array bodies 21-1, 21-2 and the through holes 15a, 15b of the semiconductor substrates 13-1, 13-2 are aligned, and the metal pins 50a, 50b are inserted.

  The outer diameters of the metal pins 50a and 50b are slightly larger than the inner diameters of the mounting holes 27a and 27b and the inner diameters of the through holes 15a and 15b. Therefore, by inserting the metal pins 50a and 50b, the mounting holes 27a and 27b and the through holes 15a and 15b are slightly expanded in diameter, and between the metal pins 50a and 50b and the mounting holes 27a and 27b and the through holes 15a and 15b. A frictional force is generated, and the metal pins 50a and 50b cannot be removed. Thereby, the lens array 20 is fixed to the semiconductor substrates 13-1 and 13-2.

[Optical path of laser light]
Each laser beam La-1 emitted from each light emitting element 11a is incident on each second lens 32 of the corresponding lens array body 21-1, and is refracted by the second lens 32 to become focused light. Each laser beam La-1 emitted from the second lens 32 is reflected by the total reflection surface 24a so as to change the direction in accordance with the angle of the total reflection surface 24a, passes through the transmission surface 25a and the transmission surface 25b, The light is refracted to be focused light by the corresponding first lens 31. Each laser beam La-1 emitted from the first lens 31 is incident on the end face of the corresponding optical fiber 40a-1.

  Each laser beam Lb-1 emitted from each light emitting element 11b is incident on each fourth lens 34 of the corresponding lens array body 21-1, and is refracted by the fourth lens 34 to become parallel light. Each laser beam Lb-1 emitted from the fourth lens 34 is reflected on the total reflection surface 25c so as to change the direction according to the angle of the total reflection surface 25c, and is converted into a focused light by the corresponding third lens 33. Refracted to be. Each laser beam Lb-1 emitted from the third lens 33 enters the end face of the corresponding optical fiber 40b-1.

  Each laser beam La-2 emitted from the end face of each optical fiber 40a-2 is incident on the first lens 31 of the corresponding lens array main body 21-2 and becomes focused light by the first lens 31. Refracted. Each laser beam La-2 emitted from the first lens 31 passes through the transmission surface 25b and the transmission surface 25a, and is reflected by the total reflection surface 24a so as to change the direction according to the angle of the total reflection surface 24a. The light is refracted to become focused light by the corresponding second lens 32. Each laser beam La-2 emitted from the second lens 32 is incident on the light receiving surface of the corresponding light receiving element 12a.

  Each laser beam Lb-2 emitted from the end face of each optical fiber 40b-2 is incident on the third lens 33 of the corresponding lens array main body 21-2 and becomes parallel light by the third lens 33. Refracted. Each laser beam Lb-2 emitted from the third lens 33 is reflected by the total reflection surface 25c so as to change the direction to a substantially right angle in accordance with the angle of the total reflection surface 25c. Refracted to be focused light. Each laser beam Lb-2 emitted from the fourth lens 34 enters the light receiving surface of the corresponding light receiving element 12b.

  As described above, in the present embodiment, the optical fiber and the photoelectric conversion elements (light emitting elements 11a and 11b) are optically formed by the lens without the optical path of the laser light La-1 and the optical path of the laser light Lb-1 intersecting each other. Combined. In the present embodiment, the optical fiber and the photoelectric conversion elements (light receiving elements 12a and 12b) are optically coupled by the lens without the optical path of the laser light La-2 and the optical path of the laser light Lb-2 intersecting each other. Combined.

[Effects and variations of this embodiment]
As described above, according to the present embodiment, the optical paths of the respective laser beams do not intersect with each other. Therefore, a connector having a compact configuration and a plurality of optical fibers arranged in four rows without causing interference or stray light. Multi-channel optical communication can be realized with

  In addition, according to the present embodiment, the transmission surface 25a and the transmission surface 25b are inclined, and the recess 25 is formed so that the cross-sectional area gradually decreases from the opening toward the back side. Since the recess 25 has a shape that ensures releasability from the mold, the lens array bodies 21-1 and 21-2 can be efficiently manufactured using the mold.

  As shown in FIG. 5, if the transmission surface 25a and the transmission surface 25b are formed perpendicular to the outer peripheral surface 21c, refraction at the transmission surface 25a and the transmission surface 25b is eliminated. Thereby, although the releasability of the concave portion 25 from the mold is somewhat inferior, the angle of the total reflection surface 24a is set to the horizontal direction in FIG. 5 regardless of the material (refractive index) of the lens array main bodies 21-1 and 21-2. The lens array bodies 21-1 and 21-2 can be easily designed and manufactured by setting the direction as a reference (0 °) to 45 ° clockwise in FIG. 5.

  In the above description, the case where 24 of the 48 photoelectric conversion elements are light emitting elements and 24 are light receiving elements has been described. However, the present embodiment is not limited to this. For example, all 48 photoelectric conversion elements may be light emitting elements, and conversely, all 48 photoelectric conversion elements may be light receiving elements.

  In the above description, the case where the number of optical fibers in each column and the number of photoelectric conversion elements in each column is 12, but the present embodiment is not limited thereto.

  In the above description, the mounting holes 27a and 27b pass through the lens array main bodies 21-1 and 21-2, and one metal pin is passed through each mounting hole 27a and 27b. The present embodiment is not limited to this. For example, after fitting the lens array body 21-1 and the lens array body 21-2, metal pins may be inserted from both ends of the mounting holes 27a and 27b. In the present embodiment, attachment holes having a predetermined depth may be provided at both ends of the outer peripheral surfaces 21a and 21c, and notches may be provided in place of the attachment holes 27a and 27b. A convex member may be used instead of the metal pin.

  The lens array and the optical module including the lens array according to the present invention can be used for multi-channel optical communication.

DESCRIPTION OF SYMBOLS 1 Optical module 10-1, 10-2 Photoelectric conversion apparatus 11a, 11b Light emitting element 12a, 12b Light receiving element 13-1, 13-2 Semiconductor substrate 20 Lens array 21-1, 21-2 Lens array main body 22, 23, 24 Notch 25 Concave part 24a, 25c Total reflection surface 25a, 25b Transmission surface 26 Fitting pin 26a, 26b Convex part 27a, 27b Mounting hole 31 First lens 32 Second lens 33 Third lens 34 Fourth lens 40 Optical fiber cable 40a-1, 40b-1, 40a-2, 40b-2 Optical fiber 41 MT connector 50a, 50b Metal pin

Claims (6)

Attached to a first substrate and a second substrate facing the first substrate;
In a connector in which 4 rows × n (n is the number per row and plural) optical fibers are aligned, the optical axes of the optical fibers are parallel to the first substrate surface and the second substrate surface. To attach,
2 × n first photoelectric conversion element groups arranged in two rows on the first substrate and having an optical axis in the normal direction of the first substrate surface, and 2 on the second substrate A lens that is arranged in a row and optically couples 2 × n second photoelectric conversion element groups having an optical axis in the normal direction of the second substrate surface and the 4 × n optical fibers. An array,
The lens array comprises a first lens array body and a second lens array body,
The first and second lens array bodies are:
N first lenses provided at positions facing the end faces of the optical fibers in the first row, which is a row far from the photoelectric conversion element;
N second lenses provided at positions facing the photoelectric conversion elements in the first row, which is a row far from the optical fiber,
N third lenses provided at positions facing the end faces of the optical fibers in the second row, which is a row closer to the photoelectric conversion element,
N fourth lenses provided at positions facing the respective photoelectric conversion elements in the second row, which is a row closer to the optical fiber,
A first light beam emitted from an end face of the first row of photoelectric conversion elements or the first row optical fibers and changing a traveling direction of light passing through a first optical path between the first lens and the second lens. 1 reflective surface;
A second light beam is emitted from an end face of the second row of photoelectric conversion elements or the second row of optical fibers and changes a traveling direction of light passing through a second optical path between the third lens and the fourth lens. Two reflective surfaces,
The first reflecting surface is provided at a position that does not interfere with the second optical path,
The second reflecting surface is provided at a position that does not interfere with the first optical path.
Lens array. Forming the second reflecting surface by a recess;
The recess has a first transmission surface and a second transmission surface that transmit light passing through the first optical path.
The lens array according to claim 1. The concave portion gradually decreases in cross-sectional area as it goes from the opening to the back side.
The lens array according to claim 2. The first transmission surface and the second transmission surface of the recess are formed perpendicular to the first optical path;
The lens array according to claim 2. In the first and second lens array bodies,
A first outer peripheral surface that is in contact with the first substrate or the second substrate at the time of assembly and a second outer peripheral surface that is the opposite surface of the first outer peripheral surface are formed in parallel;
The lens array according to any one of claims 1 to 4. 4 rows × n optical fibers in which the tips are aligned in the connector (where n is the number per row and a plurality), and
2 × n first photoelectric conversion element groups arranged in two rows on the first substrate and having an optical axis in the normal direction of the first substrate surface, and converting optical signals into electrical signals Alternatively, a first photoelectric conversion device that performs conversion from an electrical signal to an optical signal;
There are 2 × n second photoelectric conversion element groups arranged in two rows on the second substrate and having an optical axis in the normal direction of the second substrate surface, from an optical signal to an electrical signal. A second photoelectric conversion device that performs conversion or conversion from an electrical signal to an optical signal;
The lens array according to any one of claims 1 to 5, wherein the first and second photoelectric conversion elements and the optical fiber are optically coupled.
An optical module comprising:

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