JP2002189148A - Optical semiconductor element module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical semiconductor element module which has both functions of a conventional optical semiconductor element module and of a polarized wave multiplexer, with which module an optical fiber for holding polarized wave until emitted light from the optical semiconductor element is multiplexed by the multiplexer, is dispensed with. SOLUTION: The optical semiconductor module element is furnished with two optical semiconductor elements 1a and 1b together with an optical element 7 which multiplexed emited light beams from the optical semiconductor elements or demuliplexes an external light beam into each of the optical semiconductor elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of combining light from two optical semiconductor elements and guiding the combined light to one optical waveguide, or combining light from one optical waveguide into two optical semiconductor elements. The present invention relates to an optical semiconductor element module having a function of separating light into an optical semiconductor device.

[0002]

2. Description of the Related Art FIG. 5 is a transparent top view of an optical semiconductor device module on which a conventional optical semiconductor device is mounted. In the figure, 1 is an optical semiconductor element, 2 is a lens, 3 is an optical fiber, 4 is an optical connector, 5 is a module housing, and 21 is a signal terminal. Reference numeral 6 denotes the entire optical semiconductor element module. The optical semiconductor element 1 and the lens 2 are mounted on a substrate and housed in a housing 5. The optical fiber 3 and the signal terminal 21 are attached to, for example, a side surface of the housing 5 and transmit and receive electric signals and light.

When an electric signal is inputted to the signal terminal 21 of the module housing 5, a circuit pattern formed on the substrate is formed.
An electrical signal is input to the optical semiconductor device 1 via a not-shown (not shown), and the optical semiconductor device 1 converts this signal into light. The light emitted from the optical semiconductor element 1 is collected or collimated by the lens 2. The light condensed or collimated by the lens 2 is used to connect the light in the optical fiber 3 to the outside via the optical fiber 3 for taking out the light emitted from the optical semiconductor element 1 to the outside of the housing 5. And is emitted to the outside.

FIG. 6 is a perspective top view of a conventional polarization multiplexer. In the figure, 2a to 2c are lenses, 3 is an optical fiber,
4 is an optical connector, 7 is an optical element for multiplexing and separating light, for example, PBS (Polarization Beam Splitter),
8a to 8c are adapters, and 9 is a polarization multiplexer housing. 1
0 indicates the entire polarization multiplexer. PBS7, lenses 2a-2
c is mounted on the board and housed in the housing 5. Each of the adapters 8a to 8c and the optical fiber 3 are attached to, for example, a side surface of the housing 9 to transmit and receive light.

Light guided from the outside via the adapters 8a and 8b is collimated by the lenses 2a and 2b, respectively, and these collimated lights are combined by the PBS 7. The multiplexed light is further transmitted to the optical connector 4c through the adapter 8c and the optical fiber 3 via the lens 2c.
Guided to the outside.

Conversely, the optical connector 4 to the adapter 8c
When the light enters through the adapter, the light is separated by the PBS 7 and emitted to the outside from the adapters 8a and 8b.

For example, when increasing the output power for long-distance transmission, the output lights from the two optical semiconductor element modules are multiplexed by a polarization multiplexer to increase the output power. The light flow in that state is shown in FIG. 1 in the figure
1 is a polarized light 1, 12 is a polarized light 2, 13 is a multiplexed light, and 3a is a polarization maintaining optical fiber.

[0008] Conversely, the multiplexed light is converted into two light beams by the above-described polarization multiplexer.
It may be separated into two optical semiconductor element modules. FIG. 7B shows the flow of light in that state. 1 in the figure
1, 12, 13, and 3a are the same as those in FIG.

[0009]

As described above, conventionally, when multiplexing is performed by a polarization multiplexer, the incident light needs to be orthogonal to the polarization direction, so that the outgoing light from the optical semiconductor element module is required. It was necessary to maintain the polarization state by the polarization maintaining optical fiber until it was multiplexed by the polarization multiplexer.

Also, since the optical semiconductor device module and the polarization multiplexer are separated, separate housings are required for the optical semiconductor device module and the polarization multiplexer, and a lens is required for each. , Assembly time was long, and the cost of parts was higher.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and eliminates the need for a polarization maintaining optical fiber until light emitted from an optical semiconductor element is multiplexed by a polarization multiplexer. It is another object of the present invention to provide an optical semiconductor element module having both functions of a conventional optical semiconductor element module and a polarization multiplexer.

[0012]

SUMMARY OF THE INVENTION In view of the above-mentioned object, the present invention provides two optical semiconductor elements, and multiplexes light emitted from these optical semiconductor elements or applies external light to these optical semiconductor elements. An optical semiconductor element module is provided with an optical element to be separated.

Further, the two optical semiconductor elements are provided so that emitted light is at right angles to each other, and the optical element is provided at a position where an optical axis of these two optical semiconductor elements intersects. And between the optical element, and a lens for collimating or condensing the incident light provided respectively on the opposite side of the one optical semiconductor element of the optical element,
An optical waveguide for extracting and taking in light with the outside provided at the tip of a lens provided on the side of the optical element opposite to the one optical semiconductor element; and the optical semiconductor element, the optical element, the lens, and the optical waveguide. 2. The optical semiconductor element module according to claim 1, further comprising: a substrate on which the semiconductor device is mounted.

2. The optical semiconductor device according to claim 1, wherein said substrate has a stepped surface for positioning each element mounted in a XY plane in the Z-axis direction. In the element module.

The device according to claim 2 or 3, wherein the substrate has grooves for fixing the elements mounted in the XY plane, which are positioned in the XY plane direction. In the optical semiconductor element module described above.

Further, the light incident on the optical element from the two optical semiconductor elements has a direction in which the polarization component is large in a plane orthogonal to the optical axis, and these directions are shifted from each other by 90 °. 2. The device according to claim 1, wherein the element emits the light in the direction in which the polarization component is large in the same direction.
5. The optical semiconductor element module according to any one of items 1 to 4.

Further, the two optical semiconductor elements are the same optical semiconductor element in which the direction of the large polarization component is the same in a plane orthogonal to the optical axis, and the other is 90 ° with respect to the optical axis.
The optical semiconductor element module according to claim 5, wherein the optical semiconductor element module is arranged in a rotated state.

Further, the directions in which the two optical semiconductor elements have a large polarization component in a plane orthogonal to the optical axis are mutually 90 °.
6. The optical semiconductor device module according to claim 5, wherein the optical semiconductor device emits shifted light.

Further, the two optical semiconductor elements are the same optical semiconductor element having the same direction of large polarization component on a plane orthogonal to the optical axis, and the polarization plane of light is located between one optical semiconductor element and the optical element. 6. The optical semiconductor element module according to claim 5, further comprising a λ / 2 plate for rotating the substrate by 90 ° about the optical axis.

According to the optical semiconductor device module of the present invention, by arranging the two optical semiconductor devices and the PBS in the housing of the optical semiconductor device module, the light emitted from the two optical semiconductor devices without the polarization maintaining optical fiber is provided. Or a structure for splitting the multiplexed light into two optical semiconductor elements.

Further, the optical semiconductor device module has a structure in which a shape for positioning an optical semiconductor device, a lens, an optical device, and an optical waveguide is provided on a substrate in a housing of the optical semiconductor device module.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a transparent top view of an optical semiconductor element module according to one embodiment of the present invention. The same or corresponding parts as those of the conventional one are denoted by the same reference numerals. In the module case 5, two optical semiconductor elements 1a arranged so that emitted lights are at right angles to each other,
1b, an optical element PBS7, which is an optical element for multiplexing and separating light arranged at a position where the optical axes of these two optical semiconductor elements 1a, 1b intersect, and each optical semiconductor element 1a, 1b and PB
Lenses 2a to 2c provided between S7 and on the opposite side of the optical semiconductor element 1a of the PBS 7 for collimating or condensing incident light are housed in a state fixedly mounted on the substrate 14. The tip of the optical fiber 3 also extends over the substrate 14 and is fixed. This gives 2
Since the two optical semiconductor elements 1a and 1b and the PBS 7 are mounted at a short distance in the same module housing 5, a polarization maintaining optical fiber is not required.

A signal terminal 21 for connecting an electric signal to the outside and an optical fiber 3 as an optical waveguide for taking out and taking in light to the outside are provided on, for example, a side surface of the housing 5. The polarized light (1) 11 and the polarized light (2) 12 from the optical semiconductor elements 1a and 1b may have different wavelengths.

The operation is performed by the signal terminals 21 of the module housing 5.
When an electrical signal is input to the optical semiconductor elements 1a and 1b via a circuit pattern (not shown) formed on the substrate 14,
The optical semiconductor device 1 converts the signal into light. Light emitted from the optical semiconductor elements 1a and 1b is condensed or collimated by the lenses 2a and 2b, respectively. The light condensed or collimated by the lenses 2a and 2b is combined by the PBS 7. The multiplexed light is further guided to the optical connector 4 via the lens 2c and the optical fiber 3 and emitted to the outside.

Conversely, when light enters from the optical connector 4 via the optical fiber 3 as shown by the dashed arrow in FIG. 1, the light follows the opposite course, is separated by the PBS 7 and is separated by the optical semiconductor element 1a. , 1b, and the optical semiconductor elements 1a,
At 1b, the signals are converted into electric signals and taken out from the signal terminals 21, respectively.

FIG. 2 is an enlarged view of a portion of the substrate 14 in FIG. 1, (a) is a top view, and (b) is a side view. The optical semiconductor elements 1a, which are mounted and fixed
1b, lenses 2a to 2c, PBS 7 and optical fiber 3
Are fixed so that positioning can be performed so that the optical axis L is aligned without detecting actual light, and steps for positioning each element in the Z-axis direction and those for positioning each element in the XY plane direction are fixed. Grooves are formed. Although not shown, when the optical semiconductor element is a light emitting element, an optical monitoring optical semiconductor element may be required in some cases. In this case, positioning can be performed by similar steps and grooves. You.

The substrate 14 is processed with high precision by, for example, etching a substrate made of a material Si crystal, and the substrate 14 in the Z direction, ie, the vertical direction, with the optical semiconductor elements 1a, 1b, the lenses 2a to 2c, the PBS 7, and the optical fiber 3. Positioning is possible.

In the XY plane direction, that is, in the front-rear and left-right directions, alignment can be performed by, for example, an image recognition device based on a ridge line or an area appearing by etching or mask processing of the substrate 14.

In the XY plane direction, a V-shaped or U-shaped groove may be formed on the substrate 14 as shown in FIG. 3A is a side view, and FIGS. 3B and 3C are top views showing, for example, a V-shaped groove and a U-shaped groove for the optical fiber 3, respectively. For example, the lenses 2a to 2c and the optical fiber 3 having a circular cross section will be described. A groove G such as a V-shaped or U-shaped groove is formed on the substrate 14 by etching in accordance with the mounting position, and the groove is formed in accordance with the shape of the groove. Positioning can be performed by fixing each element by, for example, anodic bonding or bonding at a bonding point C. This is the same for other elements, and can be similarly realized by forming a groove at a desired position according to the shape of the element.

One of the specific purposes of multiplexing is multiplex transmission of signals by wavelength synthesis and high light output. Some optical semiconductor elements originally have a polarization component polarization (polarization extinction ratio) such as optical semiconductor elements for lasers, and since the optical output density increases in the direction where the polarization component is large, If this characteristic and PBS are used, large light combined in one direction can be extracted.

Referring to FIG. 4, the arrow in the figure represents the polarization component of light, and the length of the arrow represents the magnitude of the polarization component, that is, the magnitude of the optical output density. Here, assuming that the direction in which the polarization component is large in the plane orthogonal to the optical axis is the polarization direction,
As shown in (a), when the same optical semiconductor elements 1a and 1b are used, if the polarization directions of the two incident lights are equal, a large optical output cannot be extracted in one direction. That is, the part (horizontal direction) where the polarization component of the element 1a is large and the element 1b
Are emitted to the side opposite to the element 1a, and the part of the element 1a having a small polarization component (vertical direction) and the element 1b having a large polarization component (horizontal direction) are It is emitted to the side opposite to 1b.

As shown in (b), the same optical semiconductor element 1
When a and 1b are used, one optical semiconductor element is set up so that the polarization directions of two lights entering the PBS 7 are relatively 90 °, that is, one optical semiconductor element is centered on the optical axis with respect to the other. If it is arranged so as to be rotated by 90 °, a large light output can be taken out in one direction. That is, the portion (horizontal direction) where the polarization component of the element 1a is small and the element 1b
The portion (vertical direction) having a small polarization component is emitted to the side opposite to the element 1a, and the portion (vertical direction) having a large polarization component of the element 1a and the portion (horizontal direction) having a large polarization component of the element 1b are It is emitted to the side opposite to 1b.

As shown in (c), two optical semiconductor elements 1a and 1b whose polarization directions are different from each other by 90 °, that is, the directions of large polarization components on the plane orthogonal to the optical axis are shifted from each other by 90 °. By using, a large light output can be taken out in one direction. That is, a portion (horizontal direction) of the element 1a having a small polarization component and a portion (vertical direction) of the element 1b having a small polarization component are emitted to the side opposite to the element 1a.
A portion having a large polarization component (vertical direction) and a portion having a large polarization component (horizontal direction) of the element 1b are emitted to the side opposite to the element 1b.

As shown in (d), even when the same optical semiconductor elements 1a and 1b are used, one of the optical semiconductor elements 1a and 1b can be used.
When the λ / 2 plate 20 is interposed between the “a” and the PBS 7, the polarization plane (the plane in the direction of polarization of light in the optical axis direction) rotates by 90 °, so that a large optical output can be extracted in one direction.

[0035]

As described above, according to the present invention, two optical semiconductor elements and an optical element for combining light emitted from these optical semiconductor elements or separating external light into these optical semiconductor elements, respectively. The optical semiconductor device module is characterized by having both of them mounted thereon, so that no polarization maintaining fiber is required and the structure can be simplified as compared with the conventional structure.

Further, the two optical semiconductor elements are provided so that emitted light is at right angles to each other, and the optical element is provided at a position where the optical axes of these two optical semiconductor elements intersect. And between the optical element, and a lens for collimating or condensing the incident light provided respectively on the opposite side of the one optical semiconductor element of the optical element,
An optical waveguide for extracting and taking in light with the outside provided at the tip of a lens provided on the side of the optical element opposite to the one optical semiconductor element; and the optical semiconductor element, the optical element, the lens, and the optical waveguide. And an optical semiconductor element module further provided with a substrate on which is mounted, so that the number of parts, the cost of parts, and the assembling work time can be reduced as compared with the conventional structure.

Further, the optical semiconductor element module is characterized in that the substrate has a stepped surface for positioning in the Z-axis direction of each of the elements mounted on the XY plane in a dotted manner. Positioning of each element in the Z-axis direction, that is, the vertical direction, is facilitated.

Further, the optical semiconductor device module is characterized in that the substrate has grooves for fixing the devices mounted in the XY plane in the direction of the XY plane. Therefore, the positioning of each element in the XY plane direction, that is, in the front, rear, left, and right directions is facilitated.

The light incident on the optical element from the two optical semiconductor elements has a direction in which the polarization component is large in a plane orthogonal to the optical axis, and these directions are shifted from each other by 90 °. Since the element emits the light in the direction in which the polarization component is large in the same direction, a large light output can be extracted in one direction.

Further, the two optical semiconductor elements are the same optical semiconductor element in which the direction of the large polarization component is the same on a plane orthogonal to the optical axis.
Since the arrangement is made in a rotated state, a large light output can be taken out in one direction.

The directions in which the two optical semiconductor elements have a large polarization component on a plane perpendicular to the optical axis are 90 ° with respect to each other.
Since the optical semiconductor element emits the shifted light, a large optical output can be taken out in one direction.

Further, the two optical semiconductor elements are the same optical semiconductor element having the same direction of large polarization component in a plane orthogonal to the optical axis, and the polarization plane of light is located between one optical semiconductor element and the optical element. Is provided with a λ / 2 plate that rotates 90 ° about the optical axis, so that a large light output can be taken out in one direction.

[Brief description of the drawings]

FIG. 1 is a transparent top view of an optical semiconductor element module according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion of the substrate of FIG.

FIG. 3 is a diagram for explaining positioning and fixing of elements on a substrate according to the present invention.

FIG. 4 is a perspective view for explaining an example of a configuration for extracting a large light output in one direction according to the present invention.

FIG. 5 is a transparent top view of an optical semiconductor element module on which a conventional optical semiconductor element is mounted.

FIG. 6 is a perspective top view of a conventional polarization multiplexer.

FIG. 7 is a transparent top view for explaining the operation of a conventional device combining an optical semiconductor element module and a polarization multiplexer.

[Explanation of symbols]

1a, 1b Optical semiconductor device module, 2a to 2c lens, 3 optical fiber, 4 optical connector, 5 module housing, 6 optical semiconductor device module, 7 PBS, 1
1 polarized light 1, 12 polarized light 2, 13 multiplexed light, 14
Substrate, 20 λ / 2 plate, 21 signal terminal, G groove, L
optical axis.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 31/02 DF term (Reference) 2H037 BA03 BA12 DA02 DA11 5F073 AB04 AB25 AB27 AB28 BA01 FA06 FA13 FA16 5F088 BA16 BB01 JA12 JA13 JA14 JA20

Claims (8)

[Claims] 1. An optical device comprising: two optical semiconductor elements; and an optical element for multiplexing light emitted from these optical semiconductor elements or separating light from the outside into these optical semiconductor elements. Optical semiconductor element module. 2. The two optical semiconductor elements are provided such that emitted light is at right angles to each other, and the optical element is provided at a position where an optical axis of the two optical semiconductor elements intersects. And a lens for collimating or condensing incident light provided between the optical element and the optical element opposite to the one optical semiconductor element, and the opposite side of the optical element from the one optical semiconductor element An optical waveguide provided at the tip of the lens provided for extracting and taking in light with the outside, and a substrate on which the optical semiconductor element, the optical element, the lens and the optical waveguide are mounted. The optical semiconductor element module according to claim 1, wherein 3. The optical semiconductor according to claim 1, wherein the substrate has a stepped surface for positioning each of the elements mounted on the XY plane in the Z-axis direction. Element module. 4. The device according to claim 2, wherein the substrate is provided with grooves for fixing the elements mounted in the XY plane, which position the elements in the XY plane direction.
Or the optical semiconductor element module according to 3. 5. A light incident on the optical element from the two optical semiconductor elements has a direction in which a polarization component is large in a plane orthogonal to an optical axis, and these directions are shifted from each other by 90 °. 5. The optical semiconductor device module according to claim 1, wherein the device emits the light in the direction in which the polarization component is large in the same direction. 6. A state in which the two optical semiconductor elements are the same optical semiconductor element in which the direction of large polarization component in the plane orthogonal to the optical axis is the same, and the other is rotated 90 ° about the optical axis with respect to one. 6. The optical semiconductor element module according to claim 5, wherein the optical semiconductor element module is disposed. 7. The optical semiconductor device according to claim 5, wherein the two optical semiconductor devices are optical semiconductor devices that emit lights whose directions of polarization components on a plane orthogonal to the optical axis are shifted from each other by 90 °. The optical semiconductor element module according to the above. 8. The optical semiconductor element, wherein the two optical semiconductor elements are the same optical semiconductor element having the same direction of polarization component in a plane orthogonal to an optical axis, and a light polarization plane is provided between one optical semiconductor element and the optical element. 6. The optical semiconductor element module according to claim 5, further comprising a λ / 2 plate for rotating the light source by 90 ° about the optical axis.