JPH05273444A - Photodetection module - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a compact, high-density, practically excellent light-receiving module. In a light-receiving module having a structure in which an optical fiber is arranged in parallel with the surface of a light-receiving element, at least one of the optical fiber and the light-receiving element having at least one light-receiving portion are reflected by a condenser lens and a reflection lens. Is a flat plate microlens that is arranged so as to be optically coupled via a surface, and the lens is a flat plate microlens formed by forming at least one lens on a glass substrate, and the reflecting surface is an oblique lens optical axis of the lens. A light receiving module which is formed by processing a crossing surface and is integrated with the lens. [Effect] The optical coupling efficiency between the optical fiber of the light receiving module and the light receiving element can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light receiving module in which an optical fiber and a light receiving element are optically coupled, or a light receiving module in which an optical waveguide and a light receiving element are optically coupled, and is suitable for use in a receiver for optical communication. is there.

[0002]

2. Description of the Related Art Conventionally, as a light receiving module having an optical coupling structure of a light receiving element and an optical fiber arranged in parallel on the surface of the light receiving element, as shown in FIG. On the other hand, the reflecting surface 2 is processed by oblique polishing, and the light receiving element 4 electrically connected by the bonding wire 6 is mounted on the supporting substrate 3, and the optical fiber 1 is held in parallel with the supporting substrate 3. The light beam propagates through the optical fiber 1 and is reflected by the reflecting surface 2 to enter the light receiving portion 5 of the light receiving element 4. In the light receiving module having this structure, when mounted on the support substrate 3 such as a printed circuit board, the optical fiber 1 and the light receiving element 4 are parallel to the support substrate 3, so that the component height is low, and the size and size are small. Can be implemented.

Further, as a light receiving module having an optical coupling structure of a light receiving element and an optical waveguide, conventionally, as shown in FIG. 13, a light receiving element 4 electrically connected to a supporting substrate 3 by a bonding wire 6 is provided. Mounted with a silicon substrate 3
1 has a structure in which the optical waveguide 30 formed on 1 is held at a right angle to the support substrate 3 and a light beam propagating in the optical waveguide 30 and emitted from the end face of the optical waveguide is incident on the light receiving portion 5 of the light receiving element 4. is there.

[0004]

However, in the optical module having the conventional structure, the beam emitted from the obliquely polished reflecting surface does not have a converging property in the axial direction of the optical fiber, and therefore an ellipse having a major axis in the axial direction is used. It becomes a spot of a shape and is projected on the light receiving portion. Therefore, for example, in a high-speed light receiving module in which the capacitance of the light receiving element is reduced to improve the frequency characteristics, the diameter of the light receiving portion is as small as several tens of μm or less, so that the optical coupling efficiency is deteriorated in the elliptical emission beam spot. There is a problem of doing. Further, for the above reason, it is necessary to arrange the optical fiber and the light receiving element in close contact with each other when obtaining the required coupling efficiency, and the light receiving element is damaged when the optical fiber tip is optically aligned on the light receiving element. There is a fear. Further, when a bonding wire is provided for connecting the light receiving element to an electrode or the like on the support substrate, the bonding wire may be damaged. Therefore, an object of the present invention is to provide a small-sized light receiving module that efficiently optically couples an optical fiber and a light receiving element.

Further, in the conventional light receiving module having the structure in which the optical waveguide and the light receiving element are optically coupled, the light beam emitted from the end face of the optical waveguide has no converging property.
When obtaining the required coupling efficiency, it is necessary to dispose the optical waveguide end face and the light receiving element close to each other, and the light receiving element or the optical waveguide end face is damaged when the light receiving element and the optical waveguide end face are optically aligned. There is a fear. Further, if a bonding wire is provided for connecting the light receiving element to an electrode or the like on the substrate, the wire may be damaged. Further, since the structure is such that the plane of the optical waveguide and the plane of the supporting substrate or the plane of the light receiving element are held at a right angle, there is a problem that the entire light receiving module becomes large. Therefore,
An object of the present invention is to provide a light-receiving module in which an optical waveguide and a light-receiving element are efficiently optically coupled and the size of which can be reduced.

[0006]

According to a first aspect of the present invention, there is provided a light-receiving module having a structure in which an optical fiber is arranged in parallel with a surface of a light-receiving element. Fiber and at least one
A light-receiving module in which the light-receiving element having a plurality of light-receiving portions is arranged so as to be optically coupled with each other through a condenser lens and a reflecting surface, the lens forming at least one lens on a glass substrate. In the flat micro lens, the reflecting surface is formed by processing a surface diagonally crossing the lens optical axis of the lens, and is integrated with the lens.

In order to solve the above problems, the light receiving module according to a second aspect of the present invention is a light receiving module having a structure in which an optical fiber is arranged in parallel to the surface of a light receiving element, and at least one of the optical fiber and at least one optical fiber. A light-receiving module in which the light-receiving element having a plurality of light-receiving portions is arranged so as to be optically coupled with each other through a condenser lens and a reflecting surface, wherein the lens has at least one lens on a semiconductor substrate. It is a semiconductor lens formed, characterized in that the reflecting surface is formed by processing a surface that obliquely crosses the lens optical axis of the lens, and is integrated with the lens.

In order to solve the above-mentioned problems, the light-receiving module according to a third aspect of the present invention is the light-receiving module according to the first or second aspect, wherein the optical fiber is a spherical optical fiber whose end face is spherically processed. It is characterized by being.

In order to solve the above-mentioned problems, the light-receiving module according to a fourth aspect is the light-receiving module according to the first or second aspect, wherein the optical fiber has a lens attached to the end face of the optical fiber. It is characterized by being.

In order to solve the above-mentioned problems, the light-receiving module according to a fifth aspect of the present invention is the light-receiving module according to any one of the first to fourth aspects, wherein the exit end face of the lens is formed integrally with the reflecting surface. The light receiving element is connected to the electrode formed on the surface of the lens on the side and a bump for electrode connection.

In order to solve the above-mentioned problems, a receiving module according to a sixth aspect of the present invention is the light receiving module according to any one of the first to fourth aspects, in which an optical waveguide is used instead of an optical fiber. It is a feature.

[0012]

According to the above construction, the light beam emitted from the optical fiber is reflected by the lens having the reflecting surface toward the light receiving portion of the light receiving element on the reflecting surface of the lens, and the reflected light beam is also reflected by the lens. The light is collected by and is incident on the light receiving portion of the light receiving element. Therefore, even if the light receiving portion of the light receiving element is small, highly efficient optical coupling with the optical fiber can be obtained. Further, due to this condensing action, by appropriately disposing the optical fiber, the light receiving element and the lens, a desired distance can be provided between the lens and the light receiving element, and the surface of the light receiving element may be damaged. Even if the bonding wire is exposed from the light receiving element, the wire is not damaged. Moreover, since light collection and reflection are performed by one optical component, it is easy to configure a small light receiving module.

Also, in the light receiving module using the optical waveguide instead of the optical fiber, the same action and effect can be obtained by using the lens having the reflecting surface, and further, the optical waveguide and the light receiving element or the supporting substrate thereof. Are arranged in parallel, the light receiving module can be downsized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the light receiving module of the present invention will be described below. 1 is a sectional view of a first embodiment of the present invention. As shown in FIG. 1, a light receiving element 14 having a light receiving portion 15 is mounted on a supporting substrate 13 such as a printed circuit board, and electrodes on the supporting substrate 13 are mounted. Are electrically connected to each other by the bonding wire 16. The optical fiber 11 has a diameter of 125 μmφ, for example, and has a cleaved end face. The flat-plate microlens 17 is, for example, a flat-plate microlens having a glass plate having a refractive index distribution and a lens effect, and a part of which is optically polished by a surface that crosses the lens optical axis at, for example, 45 ° and a reflecting surface 18 is formed. Has been formed.

The flat plate microlens 17 having the reflecting surface 18 has an optical path that passes through the lens optical axis and is reflected by the reflecting surface 18, and one of the two lens end surfaces that the optical path traverses faces the end surface of the optical fiber 11. The lens end surface on the other side faces the light receiving portion of the light receiving element 14, and the optical fiber 11 and the light receiving element 14 are arranged so as to be optically coupled via the lens. The end surface of the lens passing through the optical path that does not overlap the optical axis of the lens is optically polished by a surface perpendicular to the optical path. Further, the processing method of the reflecting surface may be a processing method of cutting a part of the lens or a processing method of forming by groove processing. The processing means for optical polishing of the reflecting surface may be mechanical processing or scientific processing.

Therefore, the light beam emitted from the optical fiber 11 has the flat microlens 17 having the reflecting surface 18.
Is incident on the light receiving section 15 of the light receiving element 14 with high efficiency by being condensed and reflected by the lens effect and the reflecting surface 18 due to the refractive index distribution of the lens, emitted from the flat microlens 17. Although only the optical fiber whose end face is cleaved has been described, the optical fiber may be optically polished at a predetermined angle to prevent reflected return light.

As described above, in the light receiving module of this embodiment, the flat plate microlens 17 having the reflecting surface 18 is used, and the light emitted from the optical fiber 11 is made incident on the light receiving element 14, so that the optical fiber 11 becomes the light receiving element. They are arranged in parallel, and efficient optical coupling can be obtained. Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber outgoing light obtained by the flat plate microlens 17 is set to an arbitrary distance outside the lens outgoing end face, so that the flat microlens 17 and the light receiving light are received. It can be arranged with a distance from the element 14, and damages the bonding wire 16 connected to the light receiving element 14 even when the light receiving element 14 and the optical fiber 11 or the flat plate microlens 17 are aligned. There is no.

As described above, the first embodiment is an example of the light receiving module having the optical coupling between the single optical fiber 11 and the light receiving element 14 having the single light receiving portion 15. It is also possible to use a light-receiving module having an optical coupling between the optical fiber array including the optical fiber and the light-receiving element including the plurality of light-receiving portions or the plurality of light-receiving elements. Figure 2
The example is shown in FIG.

FIG. 2 shows a light receiving module according to the second embodiment of the present invention. In the figure, 111 is an optical fiber array in which a plurality of optical fibers 11 similar to those in FIG. Reference numeral 114 denotes a light receiving element array manufactured by aligning a plurality of light receiving portions of the light receiving element 14 similar to that in FIG. Reference numeral 117 denotes a flat plate microlens formed, for example, by arranging lens elements, which have a refractive index distribution on a glass plate and have a lens effect, aligned in an array in a lateral example. Here, the flat plate microlens 11
Reference numeral 7 is a surface that intersects the optical axis of the lens at 45 °, for example, and a part of it is optically polished to form a reflecting surface 118. Reflective surface 11
Numeral 8 is aligned so that the reflecting surface 18 of FIG. 1 is on one plane, and is preferably formed by optical polishing collectively. The array pitch of the plurality of lens elements of the flat plate microlens 117 and the array pitch of each light receiving element of the light receiving element array 114 are the same as the array pitch of each optical fiber of the optical fiber array 111.

In the flat plate microlens 117 having the reflecting surface 118, one of the two lens end surfaces that the optical path crosses is an optical fiber array for each optical path that passes through the lens optical axis of each lens element and is reflected by the reflecting surface 118. 11
The light receiving element 1 faces the end surface of the first lens and the other lens end surface is
14 and the optical fiber array 111.
Of the light beam emitted from each of the optical fibers of
It is arranged so as to enter each of the 14 light receiving portions 115.
The lens end surface passing through the optical path that does not overlap each optical axis of the lens is collectively optically polished by a surface perpendicular to the optical path.

As described above, in the light receiving module according to the second embodiment shown in FIG. 2, the flat microlenses 117 having the reflecting surface 118 are used, and the light emitted from the optical fiber array 111 is made incident on the light receiving element array 114. The optical fiber array 111 is arranged in parallel with the light receiving element array 114, and efficient optical coupling can be obtained. Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber emission light obtained by the flat plate microlens 117 is set to an arbitrary distance outside the lens emission end face, and the flat plate microlens 117 and the light receiving The light receiving element array 114 and the optical fiber array 11 can be arranged at a distance from the element array 114.
The bonding wire 116 connected to the light receiving element array 114 is not damaged even when the position 1 or the flat plate microlens 117 is aligned.

FIG. 3 is a sectional view of a third embodiment of the present invention. In FIG. 3, the optical fiber 11 and the light receiving element 14 are the same as those in the first embodiment, and the semiconductor lens 27 has a high refractive index. It is a semiconductor lens in which a semiconductor having a refractive index is used as a material, and a lens is formed on the semiconductor surface by, for example, a dry etching technique. For example, a resist pattern having lens-like undulations is formed on a semiconductor substrate by a photolithography technique, and then, for example, ion etching. It is formed by etching into a lens shape by a technique. The type of lens may be an ordinary convex lens, a Fresnel lens, or a diffractive lens. On a part of the semiconductor substrate on which the lens is formed, a surface passing through the optical axis of the lens is optically polished to form a reflecting surface 28.

The method of manufacturing the semiconductor lens and the reflecting surface is not limited to the above description. For example, as the lens manufacturing method, the ion etching method is described above. It may be formed by a method such as an ion exchange method. Also,
The processing method of the reflecting surface may be a processing method of cutting out a part of the lens or a processing method of forming by groove processing. Further, the processing means for optical polishing of the reflecting surface may be mechanical processing or chemical processing,
It may be processed by a dry etching method.

A semiconductor lens 27 having the reflecting surface 28.
Is the reflecting surface 2 of the optical path of the light beam incident on the lens.
For example, for the optical path that is reflected at 90 ° at 8,
The end surface of the lens through which the optical path passes and the end surface of the optical fiber 11 face each other, while the end surface of the lens on the other side through which the optical path passes faces the light receiving portion 15 of the light receiving element 14. The lens end surface passing through the optical path that does not overlap the optical axis of the lens is optically polished by, for example, a surface perpendicular to the optical path.

As described above, in the light receiving module of the third embodiment shown in FIG. 3, the semiconductor lens 27 having the reflecting surface 28 is used, and the light emitted from the optical fiber 11 is received.
The optical fiber 11 is arranged in parallel with the light receiving element 14 by making the light incident on the optical path 4, and efficient optical coupling can be obtained. Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber emitted light obtained by the semiconductor lens 27 is set to an arbitrary distance outside the lens emission end face, so that the semiconductor lens 27 and the light receiving element 14 are The light receiving element 14 and the light receiving element 14,
Even when the optical fiber 11 or the semiconductor lens 27 is aligned, the bonding wire 16 connected to the light receiving element 14 is not damaged.

The semiconductor lens 27 may be a semiconductor lens array manufactured by aligning a plurality of semiconductor lens elements in a horizontal row. In this case, the optical fiber array and the light receiving element array are optical fiber arrays in which a plurality of optical fibers 11 are aligned on the array as in FIG. 2, and a plurality of light receiving portions of the light receiving element 14 are arranged in a horizontal row. It is a fabricated light receiving element array. Here, the reflection surface is a part of the lens, for example, a surface that passes through the center of each semiconductor lens element is optically polished and aligned so that the reflection surface is on one plane. Is preferred. The array pitch of the plurality of lens elements of the semiconductor lens array and the array pitch of each light receiving element of the light receiving element array are the same as the array pitch of each optical fiber of the optical fiber array.

In the semiconductor lens array having the reflecting surface, for each optical path that passes through the lens optical axis of each lens element and is reflected by the reflecting surface, one of the two lens end surfaces that the optical path crosses is the optical fiber ray array 111. The light beam emitted from each optical fiber of the optical fiber array 111 passes through each lens element of the semiconductor lens array and each of the light receiving element array 114 faces the end surface and the other lens end surface faces the light receiving portion of the light receiving element. It is arranged so as to enter the light receiving portion. The lens end surface passing through the optical path that does not overlap each optical axis of the lens is collectively optically polished by a surface perpendicular to the optical path.

Therefore, in the light receiving module having the above-mentioned structure, the semiconductor lens array having the reflecting surface 28 is used, and the light emitted from the optical fiber array 111 is made incident on the light receiving element array 114, whereby the optical fiber array 111 is formed. Arranged in parallel with the light-receiving element array 114, and efficient optical coupling can be obtained. Moreover, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber output light obtained by the semiconductor lens array is set to an arbitrary distance outside the lens output end face, and thus the semiconductor lens array and the light receiving element array are arranged. 114 and the bonding wire 116 connected to the light receiving element array 114 is damaged even when the light receiving element array 114 is aligned with the optical fiber array 111 or the semiconductor lens array. There is nothing to do.

Although the optical fiber 11 and the optical fiber array 111 described in each of the above embodiments have their end faces cleaved, an optical fiber whose end face is processed into a lens shape or a condenser lens is separately attached to the end face. It may be an optical fiber. This example is shown below.

FIG. 4 is a sectional view of the fourth embodiment of the present invention. As shown in the figure, a support substrate 13 such as a printed circuit board is provided.
A light receiving element 14 having a light receiving portion 15 is mounted thereon and is electrically connected to an electrode on the support substrate 13 by a bonding wire 16. The optical fiber 11 has, for example, a diameter 12
The optical fiber 21 has a diameter of 5 μm and has a spherically-shaped end surface. In addition, the flat plate micro lens 17
Is, for example, a flat plate microlens having a glass plate with a refractive index distribution and a lens effect, and a part of which is optically polished by a surface that intersects the lens optical axis at 45 ° to form a reflecting surface 18. There is.

The flat plate microlens 17 having the reflecting surface 18 has an optical path that passes through the optical axis of the lens and is reflected by the reflecting surface 18. And the lens end surface on the other side is opposed to the light receiving portion 15 of the light receiving element 14, and the spherical optical fiber 21 and the light receiving element 14 are arranged so as to be optically coupled via the lens. ..
The end surface of the lens passing through the optical path that does not overlap the optical axis of the lens is optically polished by a surface perpendicular to the optical path. Further, the processing method of the reflecting surface may be a processing method of cutting a part of the lens or a processing method of forming by groove processing. The processing means for optical polishing of the reflecting surface may be mechanical processing or scientific processing.

Therefore, the light beam emitted from the spherical optical fiber 21 is incident on the flat plate microlens 17 having the reflecting surface 18, and due to the refractive index distribution of the lens, the lens effect and the reflecting surface 18 condense and collect light. The light is reflected, emitted from the flat plate microlens 17, and received by the light receiving portion 1 of the light receiving element 14.
It is incident on 5 with high efficiency. At this time, since the light receiving module in this embodiment uses the optical fiber whose end face is optically polished into a spherical shape as described above, reflected return light can be prevented.

Therefore, in the light receiving module of this embodiment,
By using the flat plate microlens 17 having the reflecting surface 18 and causing the light emitted from the spherical optical fiber 21 to be incident on the light receiving element 14, the optical fiber 21 having the spherical surface is arranged in parallel with the light receiving element, and the efficiency is high. Optical coupling is obtained.
Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber outgoing light obtained by the flat plate microlens 17 is set to an arbitrary distance outside the lens outgoing end face, so that the flat microlens 17 and the light receiving light are received. Element 14
The light receiving element 1 can be arranged with a distance between
4 does not damage the bonding wire 16 connected to the light receiving element 14 even when the spherical optical fiber 21 or the flat microlens 17 is aligned.

Further, in the light receiving module of the fourth embodiment, if the respective distances of the spherical optical fiber 21, the lens 17 with the reflecting surface 18, and the light receiving element 14 are optimally designed, the configuration of FIG. Further, it is possible to further improve the light collecting function and the optical coupling efficiency.

The ball-shaped optical fiber 21 may be a ball-shaped optical fiber array in which a plurality of ball-shaped optical fibers 21 are arranged in an array. In this case, the other configuration is the same as that of the light receiving module of FIG. 2, and the alignment pitch of the front-end processed optical fiber array is the same as the alignment pitch of each lens element of the light receiving element array and the lens with a reflective surface.

Therefore, in the light-receiving module having the above-described structure, the flat-plate microlens 117 having the reflecting surface is used, and the light emitted from the spherical optical fiber array is made incident on the light-receiving element array 114, whereby the optical fiber array modified spherical Are arranged in parallel with the light receiving element array 114, and efficient optical coupling can be obtained. Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber emission light obtained by the flat plate microlens 117 is set to an arbitrary distance outside the lens emission end face, and the flat plate microlens 117 and the light receiving The light receiving element array 11 can be arranged with a distance from the element array 114.
4 does not damage the bonding wire 116 connected to the light receiving element array 114 even when aligning the spherical optical fiber array or the flat microlens 117. The above-mentioned light receiving module uses a spherically processed optical fiber in which the end face of the optical fiber is optically polished into a spherical shape, so that reflected return light can be prevented.

Therefore, in the light-receiving module having the above-mentioned structure, if the distances between the front-end processed optical fiber array, the lens with the reflecting surface, and the light-receiving element array are optimally designed, the light-receiving module having the structure shown in FIG. It is possible to improve the optical function and the optical coupling efficiency.

FIG. 5 is a sectional view of the fifth embodiment of the present invention. As shown in the figure, a support substrate 13 such as a printed circuit board is provided.
A light receiving element 14 having a light receiving portion 15 is mounted thereon and is electrically connected to an electrode on the support substrate 13 by a bonding wire 16. The optical fiber 11 has, for example, a diameter 12
It has a diameter of 5 μm and has a cleaved end face. And
Reference numeral 19 denotes a condenser lens for condensing the light emitted from the optical fiber 11, and the optical fiber 11 and the lens 11 are integrated, for example, by being adhered or attached to the same holder. It is formed as a fiber. The flat plate microlens 17 is, for example, a flat plate microlens having a lens effect by giving a refractive index distribution to a glass plate, and a part of the flat plate microlens is optically polished by a surface crossing the lens optical axis at 45 °, for example. A reflecting surface 18 is formed.

In the flat plate microlens 17 having the reflecting surface 18, the optical path passing through the optical axis of the lens and reflected by the reflecting surface 18 has one of the two end surfaces of the lens crossing the optical path and the end surface of the optical fiber with a lens. The lens end surface on the other side faces the light receiving portion of the light receiving element 14, and the optical fiber with lens and the light receiving element 14 are arranged so as to be optically coupled via the lens. The end surface of the lens that passes through the optical path that does not overlap the optical axis of the lens is optically polished by a surface that is perpendicular to the optical path. The processing method of the reflecting surface may be a processing method of cutting out a part of the lens or a processing method of forming by groove processing. The processing means for optical polishing of the reflecting surface may be mechanical processing or scientific processing.

Therefore, the light beam emitted from the optical fiber with a lens is incident on the flat plate microlens 17 having a reflecting surface 18, and is condensed and reflected by the lens effect and the reflecting surface 18 due to the refractive index distribution of the lens. Then, the light is emitted from the flat plate microlens 17 and enters the light receiving portion 15 of the light receiving element 14 with high efficiency.

As described above, in the light receiving module of the present embodiment, the flat plate microlens 17 having the reflecting surface 18 is used, and the light emitted from the optical fiber with lens is made incident on the light receiving element 14, so that the optical fiber with lens is received. The elements are arranged in parallel with each other, and efficient optical coupling is obtained. Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber outgoing light obtained by the flat plate microlens 17 is set to an arbitrary distance outside the lens outgoing end face, so that the flat microlens 17 and the light receiving light are received. It can be disposed with a distance from the element 14, and damages the bonding wire 16 connected to the light receiving element 14 even when the light receiving element 14 and the optical fiber with a lens or the flat plate microlens 17 are aligned. Never.

Further, in the light receiving module having the above-mentioned structure, if the respective distances of the optical fiber with lens, the lens 17 with reflecting surface, and the light receiving element 14 are optimally designed, the light collecting function is further improved as compared with the structure of FIG. And it is possible to improve the optical coupling efficiency.

The lens 19 and the optical fiber 11 in the above embodiment are a lens array in which a plurality of lens elements are arranged in an array and an optical fiber array in which a plurality of optical fibers are arranged in an array. Good. In this case, the optical fiber array and the lens array are the same as above.
For example, they are adhered or attached to the same holder, and integrated to form an optical fiber array with a lens. The other configuration is the same as that of the light receiving module of FIG. 2, and the alignment pitch of the lens array and the optical fiber array is the same as the alignment pitch of the lens elements of the light receiving element array and the lens with a reflective surface. For the lens array, a flat plate microlens may be used, a semiconductor lens may be used, or any lens having the same pitch as the pitch of other optical fiber arrays may be used.

Therefore, in the light receiving module having the above structure, the flat plate microlens 117 having the reflecting surface 118 is formed.
By making the light emitted from the optical fiber array with a lens array incident on the light receiving element array 114 by using, the optical fiber array with a lens array is arranged in parallel with the light receiving element array 114, and efficient optical coupling can be obtained. .. Further, by setting an appropriate optical design and an appropriate optical arrangement, the condensing point of the optical fiber outgoing light obtained by the flat plate microlens 117 is set to an arbitrary distance outside the lens outgoing end face, and the flat plate microlens 117 and the light receiving It can be arranged with a distance from the element array 114, and even when the light receiving element array 114 and the optical fiber array with a lens array or the flat plate microlens 117 are aligned, the bonding connected to the light receiving element array 114 It does not damage the wire 116.

Further, in the light receiving module having the above-described structure, if the respective distances of the optical fiber array with the lens array, the lens with the reflecting surface, and the light receiving element array are optimally designed, the distance becomes more than that of the light receiving module having the structure of FIG. It is possible to improve the light collecting function and the optical coupling efficiency.

In the fourth and fifth embodiments, FIG. 1 and FIG.
Although only the configuration of FIG. 3 has been described, in the configuration of the light receiving module of FIG. 3, instead of the optical fiber 11 and the optical fiber array 111, the spherical optical fiber 21, the spherical optical fiber array or the optical fiber 11 or lens with the lens 19 is used. A configuration using an optical fiber array with an array may be used.

FIG. 6 is a sectional view of a flat microlens having a reflecting surface and a light receiving element in the light receiving module according to the sixth embodiment of the present invention. As shown in FIG. This is an example in which and are connected by bumps. When the light receiving element 34 is mounted on the lens surface of the flat plate microlens 17 or the flat plate microlens 117 or the semiconductor lens 27 described in the other embodiments, the flat plate microlens 37 has an optical receiving portion 35 and a lens 37. The bump electrode 40a is formed by a semiconductor manufacturing technique at a position where the bump electrode 40a can be connected to. The bump electrode 40a may be formed before or after the reflective surface 38 of the lens 37 is formed. The lens 3
The lens 7 is supported by, for example, a support 39.
A lead wire 42 from the bump electrode 40a is formed on the bump 7.

On the other hand, when the light receiving element is also mounted on the light receiving element 34 side, the bump electrode 40 is formed at a position where the light receiving portion 35 and the lens 37 can be optically coupled by the semiconductor manufacturing technique.
b and bumps 41 are formed. Where bump 4
1 may be formed on the light receiving element 34 or may be formed on the lens 37.

The light receiving element 34 and the lens 37 are integrated by accurately aligning and connecting the respective electrodes, and are integrated from the incident side surface of the lens 37 to the optical fiber described in the other embodiments. Appropriate lens design and optical arrangement are made so that the emitted light is made to enter into the light receiving element so as to be optically coupled efficiently.

As shown in FIG. 7, the light receiving module according to the sixth embodiment has an optical fiber 11 and a light receiving element 34.
Are arranged so as to be optically coupled via the lens 37. On the other hand, the light receiving element 34 connected to the lens 37 by the bump 41 is connected via the lead wiring 42.
The electrodes on the wiring substrate 43 are connected by bonding wires 46 and the like. Here, as shown in FIG.
May have a structure that also functions as a support.

Therefore, the light receiving module of the sixth embodiment described above provides an efficient optical coupling between the light receiving element and the optical fiber, similar to the functions and effects of the light receiving modules of the first to fifth embodiments described above. Therefore, the light receiving module can be downsized.

Further, in the first to sixth embodiments described above, regarding the coupling between the optical fiber and the light receiving element, the light receiving module using the lens having the reflecting surface has been described. An optical waveguide may be used instead of the optical fiber forming the light receiving module of the embodiment.

FIG. 9 is a sectional view of the light receiving module of the seventh embodiment. As shown in the figure, a light receiving element 14 having a light receiving portion 15 is mounted on a printed circuit board 13 and electrically connected to an electrode on the support substrate 13 by a bonding wire 16. The optical waveguide 51 is, for example, a silica-based waveguide having a core cross section of 10 μm square formed on a silicon substrate 52, and has an end face optically polished. The flat plate microlens 17 is similar to that of the first embodiment and has a reflecting surface 18. The flat plate microlens 17 having the reflecting surface 18 has an optical path that passes through the optical axis of the lens and is reflected by the reflecting surface 18, one of the two lens end surfaces that the optical path traverses is opposite to the end surface of the optical waveguide 51, and the other side. The lens end face of is opposed to the light receiving portion of the light receiving element 14, and the optical waveguide 51 and the light receiving element 14 are arranged so as to be optically coupled via the lens. As described above, the structure of the light receiving module of the seventh embodiment is the same as that of the light receiving module of the first embodiment described above except that the optical fiber is replaced by an optical waveguide. Therefore, the description thereof will be omitted.

Therefore, in the light receiving module of the seventh embodiment, the plate microlens 17 having the reflecting surface 18 is used, and the light emitted from the optical waveguide 51 is made incident on the light receiving element 14 to obtain an efficient optical coupling. Moreover, since the optical waveguide 51 can be arranged in parallel with the light receiving element 14, a smaller light receiving module can be configured.

Further, by performing an appropriate optical design and optical arrangement, the converging point of the light emitted from the optical waveguide obtained by the flat plate microlens 17 is set to an arbitrary distance outside the exit facet of the lens, whereby the flat plate microlens is set. 1
7 and the light receiving element 14 can be arranged with a distance therebetween, and even when the light receiving element 14 and the optical waveguide 51 or the flat plate microlens 17 are aligned,
It is possible to obtain the same effects and actions as those of the above-described first embodiment such that the bonding wire 16 connected to is not damaged.

FIG. 10 is a sectional view of a light receiving module according to the eighth embodiment of the present invention. As shown in the figure, the light receiving module of the eighth embodiment is formed on a flat plate microlens 37 with a reflecting surface 38 to which the light receiving element 34 described in the sixth embodiment is connected by bumps 41 and a silicon substrate 52. The arranged optical waveguides 51 are arranged in parallel on the same plane, while the light receiving elements 34 connected to the lenses 37 by the bumps 41 are connected to the electrodes on the wiring board 43 and the bonding wires 46 via the lead wires 42. The configuration is connected by. Here, as shown in FIG. 11, the wiring board 43 may also serve as a support.

As described above, in the light receiving module of the eighth embodiment, the light propagating in the optical waveguide 51 is emitted from the end face of the optical waveguide, enters from the incident end face of the flat plate microlens 37, and is condensed. The light receiving portion 3 of the light receiving element 34 which is reflected and bump-connected inside the flat plate macro lens 37.
It is a structure that enters and couples with 5.

Therefore, in the light receiving module of the eighth embodiment, a highly efficient optical coupling between the optical waveguide and the light receiving element can be obtained,
A small light receiving module can be constructed. Furthermore, since the optical waveguide 51 and the support base 39 on which the flat plate microlens 37 is mounted are arranged in parallel on the same plane,
When manufacturing the light-receiving module, the optical alignment between the light-receiving element 34 and the optical waveguide 51 can be easily adjusted by moving either one of the two in a plane.

As described above, in the light receiving modules of the first to eighth embodiments, the light emitted from the optical fiber is reflected by the flat plate microlenses 17, 37, the flat plate microlens 117 and the semiconductor lens 27. 18, 3
The lens is arranged or optically polished so that it reflects only at a right angle on 8, 28 and 118 and goes straight on the other optical paths. However, if it can be optically coupled to the light receiving element of the light receiving element 14 or the light receiving element array 114, which It may be arranged or polished at such an angle. That is, the lens with a reflecting surface itself may be arranged to be tilted with respect to the optical path described in each embodiment, or the reflecting surfaces 18, 38, 28, 118 may be 45 with respect to the optical axis of the lens.
It may be optically polished at an angle other than °, or the above-mentioned reflective surface 1
The lens end face passing through 8, 38, 28, 118 and the optical path not overlapping the optical axis of the lens may be optically polished at an angle other than a right angle. Further, the reflective surface is described as an optically polished surface, but the surface may be coated with a dielectric multilayer film or a metal film. Further, a reflection film coating may be applied to the end surface of the lens through which the light rays pass.

[0060]

Therefore, the light-receiving module according to the present invention has a high optical coupling efficiency between the optical fiber and the light-receiving element, is small in size, and can be mounted at a high density. In addition, there is no danger of damaging the light receiving element or the bonding wire during assembly, which is an excellent effect in practical use. Further, the light receiving module according to the present invention has a high optical coupling efficiency even in the configuration of the optical waveguide and the light receiving element, and can be mounted in a small size and a high density.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a light receiving module according to a first embodiment.

FIG. 2 is an explanatory diagram showing a light receiving module according to a second embodiment.

FIG. 3 is an explanatory diagram showing a light receiving module according to a third embodiment.

FIG. 4 is an explanatory diagram showing a light receiving module according to a fourth embodiment.

FIG. 5 is an explanatory diagram showing a light receiving module according to a fifth embodiment.

FIG. 6 is an explanatory diagram showing a portion of a flat plate microlens having a reflecting surface and a light receiving element in the light receiving module according to the sixth embodiment.

FIG. 7 is an explanatory diagram showing a configuration example of a light receiving module according to a sixth embodiment.

FIG. 8 is an explanatory diagram showing a configuration example of a light receiving module according to a sixth embodiment.

FIG. 9 is an explanatory diagram showing a light receiving module according to a seventh embodiment.

FIG. 10 is an explanatory diagram showing a configuration example of a light receiving module according to an eighth embodiment.

FIG. 11 is an explanatory diagram showing a configuration example of a light receiving module according to an eighth embodiment.

FIG. 12 is an explanatory diagram showing a configuration of a conventional light receiving module.

FIG. 13 is an explanatory diagram showing a conventional light receiving module configured to optically couple an optical waveguide and a light receiving element.

[Explanation of symbols]

 1 Optical Fiber 2 Reflecting Surface 3 Supporting Substrate 4 Light-Receiving Element 5 Light-Receiving Section 6 Bonding Wire 11 Optical Fiber 13 Supporting Substrate 14 Light-Receiving Element 15 Light-Receiving Surface 16 Bonding Wire 17 Flat Micro Lens 18 Reflecting Surface 19 Condensing Lens 21 Precursor Processing Light Fiber 27 Semiconductor lens 28 Reflective surface 30 Optical waveguide 31 Silicon substrate 51 Optical waveguide 52 Silicon substrate 34 Light receiving element 35 Light receiving portion 37 Flat plate microlens 38 Reflective surface 39 Support 40a Lens side bump electrode 40b Light receiving element side bump electrode 41 Bump 42 Leader Wiring 43 Wiring board 46 Bonding wire 111 Optical fiber array 113 Support substrate 114 Light receiving element array 115 Light receiving part 116 Bonding wire 117 Flat plate microlens 118 Reflective surface

Claims (6)

[Claims] 1. A light-receiving module having a structure in which an optical fiber is arranged in parallel with the surface of a light-receiving element, wherein at least one of the optical fiber and the light-receiving element having at least one light-receiving portion are provided with a condenser lens. And a light receiving module arranged so as to be optically coupled via a reflection surface, wherein the lens is a flat plate microlens formed by forming at least one lens on a glass substrate, and the reflection surface is the lens. A light-receiving module, which is formed by processing a surface diagonally crossing the lens optical axis and is integrated with the lens. 2. A light-receiving module having a structure in which an optical fiber is arranged in parallel with the surface of a light-receiving element, wherein at least one of the optical fiber and the light-receiving element having at least one light-receiving portion have a condenser lens. And a light receiving module arranged to be optically coupled via a reflection surface, wherein the lens is a semiconductor lens formed by forming at least one lens on a semiconductor substrate, and the reflection surface is the lens. Formed by processing the surface diagonally crossing the lens optical axis,
A light-receiving module integrated with the lens. 3. The light-receiving module according to claim 1 or 2, wherein the optical fiber is a sphere-processed optical fiber in which an end face of the optical fiber is spherically processed. 4. The light receiving module according to claim 1 or 2, wherein the optical fiber is a lensed optical fiber having a lens attached to an end face of the optical fiber. 5. The light-receiving module according to claim 1, wherein an electrode formed on the lens surface on the emission end face side of the lens formed integrally with the reflection surface and an electrode connection bump. The light receiving module is characterized in that the light receiving element is connected by the. 6. The light receiving module according to claim 1, wherein an optical waveguide is used instead of the optical fiber.