JP2000249868A - Fiber mount type optical transceiver module with filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber mount type optical transceiver module with filter transceiving a beam of an elemental light emission wavelength in the state preventing the beam of a transmission line wavelength from making incident on a photodetector and the reflected beam of the transmission line wavelength from returning to the transmission line. SOLUTION: This optical transceiver module is constituted so that the beam of the elemental light emission wavelength emitted from a light emitting element 2 is made incident on a first waveguide 8, and is transmitted through a filter film 13 from a second waveguide 7, and is coupled to the fiber 4 with the filter to be sent to the transmission line, and the beam of the elemental light emission wavelength sent from the transmission line is transmitted through the filter film 13 of the fiber 4 with the filter, and is coupled to the second waveguide 7, and is branched to two parts by a Y-shaped branch path, and is made incident on the photodetector from a third waveguide 9, and the beam of the transmission line wavelength sent from the transmission line is reflected by the filter film 13 of the fiber 4 with the filter, and isn't coupled to the second waveguide 7, and the reflected beam of the transmission line wavelength reflected by the filter film 13 isn't returned to the transmission line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication module, and more particularly to an optical communication module in which light having a transmission line wavelength is prevented from entering a light receiving element and reflected light having a transmission line wavelength is prevented from returning to a transmission path. The present invention relates to a fiber-mounted optical transceiver module with a filter capable of transmitting and receiving light having an emission wavelength.

[0002]

2. Description of the Related Art As a prior art using a fiber with a filter, for example, there is one disclosed in Japanese Patent Application Laid-Open No. Sho 62-229109 (first prior art). That is, in the first prior art, an interference film filter is formed by vapor deposition on the end face of the first fiber which is obliquely polished, and has a function of being coupled to the second fiber at the first wavelength and to the third fiber at the second wavelength. It is an optical element having. As another conventional technique, there is one described in, for example, Japanese Patent Application Laid-Open No. 57-68940 (second conventional technique). That is, in the second prior art, one end of an optical fiber is formed into an oblique shape, an interference filter film is provided on the oblique surface, and light emitting and receiving means having a wavelength of light totally reflected by the film and a wavelength of light transmitted therethrough are provided. This is a multiplex transmission method for obtaining optical wavelength multiplex transmission.

[0003]

However, in the first and second prior arts, a filter film is provided to separate the paths of the first and second wavelengths. It is necessary to couple with a fiber or a light emitting element, and there has been a problem that the precision of the polishing angle of the fiber tip and the mounting precision of the fiber or the light emitting element become very severe. In the prior art, fiber to fiber,
There is also a problem that the optical axis needs to be adjusted in order to couple the fiber with the light emitting / receiving element.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to make light having a transmission path wavelength incident on a light receiving element and return reflected light having a transmission path wavelength to a transmission path. Another object of the present invention is to provide a fiber-mounted optical transceiver module with a filter capable of transmitting and receiving light having an element emission wavelength in a state in which light is prevented.

[0005]

The gist of the present invention resides in a state in which light having a transmission line wavelength is prevented from entering a light receiving element and reflected light having a transmission line wavelength is returned to a transmission line. A fiber-mounted optical transmitter / receiver module with a filter capable of transmitting and receiving light having an element emission wavelength, wherein light having an element emission wavelength emitted from a light emitting element is incident on a first waveguide and a filter film is formed from a second waveguide. The transmitted light is coupled to the filter-equipped fiber and sent to the transmission path, and the light of the element emission wavelength sent from the transmission path is transmitted through the filter film of the filter-equipped fiber to the second waveguide. While being coupled, the light is branched into two by a Y-shaped branch path, is incident on the light receiving element from the third waveguide, and is transmitted from the transmission path at the wavelength of the transmission path. The tip is obliquely polished so that the reflected light of the transmission line wavelength reflected by the filter film is not coupled to the second waveguide and reflected by the filter film does not return to the transmission line. The present invention resides in a fiber-mounted optical transmitter / receiver module with a filter, characterized in that reflected light of the transmission line wavelength is reflected by the fiber with a filter. According to a second aspect of the present invention, the filter film is formed at a portion serving as a connection point between the fiber with a filter and the first to third waveguides. And a fiber-mounted optical transceiver module with a filter described in (1). According to a third aspect of the present invention, there is provided a fiber-mounted optical transceiver module with a filter according to the first aspect, wherein the filter film is formed in advance by vapor deposition on the tip of the fiber with the filter. Exist. According to a fourth aspect of the present invention, a slit for abutment is formed obliquely in a horizontal direction in accordance with a polishing angle of a tip portion of the fiber with a filter. 4. A fiber-mounted optical transmission / reception module with a filter according to any one of Items 3 to 3.
The gist of claim 5 of the present invention is that a slit for abutment is formed obliquely at a predetermined angle with respect to a vertical direction of the optical waveguide substrate in accordance with a polishing angle of a tip portion of the fiber with a filter. The fiber-mounted optical transceiver module with a filter according to any one of claims 1 to 3, wherein: The gist of claim 6 of the present invention is that the abutting slit is positioned by the V-groove and the abutting slit in a state of being adjusted to a polishing angle of a tip portion of the fiber with a filter. The fiber-mounted optical transceiver module with filter according to claim 5, wherein the fiber with filter is tilted and formed on the side of the fiber fixing substrate to which the fiber with filter is fixed. The gist of claim 7 of the present invention is that the abutting slit is tilted toward the light emitting element and the light receiving element in a state in which the slit for the abutment is adjusted to a polishing angle of a tip portion of the fiber with a filter. The fiber-mounted optical transceiver module with a filter according to claim 5, wherein the optical transceiver module is formed. The gist of claim 8 of the present invention is that the light receiving element is mounted on a light receiving element carrier instead of an optical waveguide substrate, and light emitted from the third waveguide is incident on the light receiving element. The fiber-mounted optical transceiver module with a filter according to any one of claims 1 to 3, wherein the light-receiving element carrier is mounted at a predetermined position.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of each embodiment described below are as follows.
Function of preventing incident to the light receiving element 3 of the transmission line wavelength lambda ₂ of the light, and has a function of preventing the return of the transmission path of the transmission path wavelength lambda ₂ of the reflected light, the light of the element emission wavelength lambda ₁ Being able to send and receive. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of a fiber-mounted optical transceiver module with a filter according to the present invention.
It is a lineblock diagram of an embodiment. Referring to FIG. 1, the fiber-mounted optical transceiver module with a filter includes an optical waveguide substrate 1, a light-emitting element 2, a light-receiving element 3, a fiber 4 with a filter, and a fiber fixing substrate 5.

The optical waveguide substrate 1 has a Y-shaped branch 6, waveguides 7,..., 9, an electrode 10 for mounting the light emitting element 2 and the light receiving element 3, and a V-groove for positioning the fiber 4 with the filter. 11. A slit 12 for abutting a fiber with a filter is formed. Fiber with filter 4
Is polished obliquely, and a filter film 13 that transmits light having an element emission wavelength λ ₁ and blocks light having a transmission line wavelength λ ₂ is formed by vapor deposition on the end face of the end of the fiber 4 with a filter.

The light emitting element 2 and the light receiving element 3 are fixed to the electrode 10 of the optical waveguide substrate 1 by soldering, and the fiber 4 with the filter is positioned on the fiber fixing substrate 5 by the V groove 11 and the slit 12. Is fixed using an adhesive. Waveguide 7 and fiber 4 with filter
The transparent resin 14 for refractive index matching is applied to the coupling portion of the above, and an effect is obtained that the coupling loss between the waveguide 7 and the filter-fitted fiber 4 can be reduced.

[0010] That is, the above-mentioned prior art uses the filter membrane 1.
Since it is necessary to couple the light reflected by 3 with the fiber or the light emitting element 2, the accuracy of the polishing angle of the fiber tip,
In addition, the mounting accuracy of the fiber and the light emitting element 2 becomes extremely strict. On the other hand, the fiber mounted optical transceiver module with a filter of the present embodiment does not need to couple the reflected light from the filter film 13, so that the polishing angle , The cost of the filter-equipped fiber 4 can be reduced, and the module yield can be improved. Further, in the above-described conventional technology, optical axis adjustment is required to couple the fiber to the fiber and the fiber to the light emitting / receiving element. In the present invention, the position of the fiber is adjusted by the V groove 1 formed in the optical waveguide substrate 1.
Since the positioning is performed by the slit 1 and the slit 12, the fiber can be mounted without adjusting the optical axis, and the assembly cost of the module can be reduced.

Next, the operation of the fiber-mounted optical transceiver module with a filter according to this embodiment will be described with reference to FIG. Light having an element emission wavelength λ ₁ emitted from the light emitting element 2 is incident on the waveguide 8, and is transmitted from the waveguide 7 to the filter film 1.
3, the light is transmitted through a transmission line (not shown).

On the other hand, light having an element emission wavelength λ ₁ transmitted from a transmission line (not shown) is transmitted through the filter film 13 of the filter-attached fiber 4, is coupled to the waveguide 7, and passes through the Y-shaped branch 6. The light is branched into two and is incident on the light receiving element 3 from the waveguide 9. Further, the optical transmission path transmission line wavelength lambda ₂ transmitted from the (not shown) is reflected by the filter film 13 of the filter with fibers 4, not coupled to the waveguide 7.
Further, the distal end portion of the filter-tipped fiber 4 because it is polished obliquely, the transmission line wavelength lambda ₂ of the light reflected by the filter film 13 is prevented from returning to the transmission line (not shown). Thus, have a function of preventing the return of the function to prevent the incidence of the light receiving element 3 of the transmission line wavelength lambda ₂ of the light, and the transmission path of the reflected light of the transmission path wavelength lambda ₂ of the light (not shown) Thus, a module for transmitting and receiving light having the element emission wavelength λ1 is obtained.

As described above, the first embodiment has the following advantages. The first effect is that the number of components can be reduced and the number of mounting steps can be reduced, and the cost can be reduced. The reason is that it is not necessary to connect a wavelength demultiplexer / multiplexer for cutting off the transmission line wavelength of λ ₂ outside the module as in the related art, so that the cost of parts can be reduced. Also, the waveguides 7,.
This is because there is no need for a troublesome assembling step of sandwiching the filter in the middle of the path of the filter-attached fiber 4, and thus the assembly cost can be reduced. The second effect is that the number of connection points of the waveguides 7,..., 9 and the fiber with filter 4 can be reduced, and the loss in the path can be minimized. The reason is that a wavelength demultiplexer / multiplexer is connected to the outside of the module or a filter is inserted in the waveguides 7,... Point or more waveguides 7, ..., 9
In the module according to the present invention, the connection point between the fiber 4 with the filter and the waveguides 7,. This is because, since the film 13 is deposited, there is no need to add a new connection point, and the loss in the path can be minimized. A third effect is that automation of module assembly and mass production are easy. The reason for this is that it is difficult to automate a complicated process such as inserting a filter in the middle of the paths of the waveguides 7,... This is because, in the module of the present invention, the filter film 13 is previously formed on the tip of the filter-fitted fiber 4 by vapor deposition, which is not suitable for production, so that the step of mounting the filter film 13 is omitted. Further, the fiber mounting is a simple process of fitting into the V-groove 11 formed in the optical waveguide substrate 1, abutting against the slit 12, and pressing and fixing the fiber fixing substrate 5 from above, so that automation is easy. ,
This is because it is suitable for mass production. And the fourth effect is
An improvement in the yield of module assembly can be expected. The reason is that, in the module of the present invention, it is not necessary to couple the reflected light from the filter film 13 to the fiber 4 with a filter or the like. Therefore, the polishing angle of the tip of the fiber 4 with a filter, the mounting accuracy of the fiber 4 with a filter, and the slit This is because it is less likely to be affected by the processing accuracy and the like of the module 12, so that the yield and stability of module assembly can be expected to be improved.

(Second Embodiment) Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 6 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a second embodiment of the present invention. Note that the same parts as those already described in the above embodiment are denoted by the same reference numerals, and redundant description will be omitted. The present embodiment is characterized in that abutment slits 12 are formed obliquely in the horizontal direction in accordance with the polishing angle of the tip of the fiber 4 with a filter. Since the slit 12 is formed obliquely, the gap between the filter film 13 and the waveguide 7 is eliminated, so that the coupling loss between the waveguide 7 and the fiber 4 with a filter can be reduced.

(Third Embodiment) Next, a third embodiment of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 8 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a third embodiment of the present invention. Note that the same parts as those already described in the above embodiment are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, the abutting slit 12 is formed obliquely at a predetermined angle with respect to the vertical direction (perpendicular to the optical waveguide substrate 1) in accordance with the polishing angle of the tip of the fiber 4 with a filter.
That is, it is characterized in that the butting slit 12 is formed to be inclined toward the fiber fixing substrate 5. As described above, since the slit 12 is formed obliquely, the gap between the filter film 13 and the waveguide 7 is eliminated, so that the coupling loss between the waveguide 7 and the fiber 4 with a filter can be reduced. Play.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 9 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a fourth embodiment of the present invention. Note that the same parts as those already described in the above embodiment are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, the abutting slit 12 is formed obliquely at a predetermined angle with respect to the vertical direction (perpendicular to the optical waveguide substrate 1) in accordance with the polishing angle of the tip of the fiber 4 with a filter.
That is, it is characterized in that the butting slit 12 is formed to be inclined toward the light emitting element 2 and the light receiving element 3. As described above, since the slit 12 is formed obliquely, the gap between the filter film 13 and the waveguide 7 is eliminated, so that the coupling loss between the waveguide 7 and the fiber 4 with a filter can be reduced. Play.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 13 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a fifth embodiment of the present invention. Note that the same parts as those already described in the above embodiment are denoted by the same reference numerals, and redundant description will be omitted. In this embodiment, the light receiving element 3 is mounted not on the optical waveguide substrate 1 but on the light receiving element carrier 15, and the light emitting element carrier 15 is located at a position where the light emitted from the waveguide 9 is incident on the light receiving element 3. It has a feature in the configuration to be mounted. In the present embodiment, since the front-illuminated light receiving element 3 conventionally used can be easily used as the light receiving element 3, an inexpensive light receiving element 3 can be used, and module cost can be reduced. It works.

It is to be noted that the present invention is not limited to the above embodiments, and each embodiment can be appropriately modified within the scope of the technical idea of the present invention. Further, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment,
The number, position, shape, and the like suitable for carrying out the present invention can be obtained. In each drawing, the same components are denoted by the same reference numerals.

[0019]

Since the present invention is configured as described above, the following effects can be obtained. The first effect is that the number of components can be reduced and the number of mounting steps can be reduced, and the cost can be reduced. The reason for this is that it is not necessary to connect a wavelength demultiplexer / demultiplexer for blocking the transmission line wavelength outside the module as in the related art, so that the cost of parts can be reduced. This is because it is not necessary to perform a complicated assembling process such as sandwiching a filter in the middle of a wave path or a path of a fiber with a filter, so that assembly cost can be reduced.

The second effect is that the number of connection points of the waveguide and the fiber with a filter can be reduced, and the loss in the path can be minimized. The reason is that when a wavelength demultiplexer / multiplexer is connected to the outside of the module or a filter is inserted in the middle of the waveguide or the fiber with the filter as in the prior art, one or two or more waveguides or filters are used. In the module of the present invention, a filter film is originally deposited on a portion that becomes a connection point between a fiber with a filter and a waveguide. This is because there is no additional connection point, and the loss in the route can be minimized.

The third effect is that module assembly can be automated.
And mass production is easy. The reason is that it is difficult to automate a complicated process such as sandwiching a filter in the middle of the path of a waveguide or a fiber with a filter as in the related art, and it is not suitable for mass production because it has to rely on human hands. On the other hand, in the module of the present invention, since the filter film is previously formed on the tip of the fiber with a filter by vapor deposition, the step of mounting the filter film is omitted. This is because it is a simple process of fitting into the V-groove formed in the above, abutting against the slit, and pressing and fixing from above with the fiber fixing substrate, so that automation is easy and suitable for mass production.

A fourth effect is that an improvement in the yield of module assembly can be expected. The reason is that in the module of the present invention, since it is not necessary to couple the reflected light from the filter film to the fiber with a filter, the polishing angle of the tip of the fiber with the filter, the mounting accuracy of the fiber with the filter, the processing accuracy of the slit, etc. This is because the module is less susceptible to the influence of the module assembly, so that the yield and stability of module assembly can be expected.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a fiber-mounted optical transceiver module with a filter according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical waveguide board 2 ... Light emitting element 3 ... Light receiving element 4 ... Fiber with a filter 5 ... Fiber fixing substrate 6 ... Y-shaped branch path 7 ... Waveguide (second waveguide) 8 ... Waveguide (first waveguide) 9 ... waveguide (third waveguide) 10 ... electrode 11 ... V-groove 12 ... slit for abutting fiber with filter 13 ... filter film 14 ... resin 15 ... carrier for light receiving element

Claims (8)

[Claims] 1. A fiber-mounted optical transceiver module with a filter capable of transmitting and receiving light of an element emission wavelength while preventing light having a transmission line wavelength from entering a light receiving element and returning reflected light having a transmission line wavelength to a transmission path. Wherein light having an element emission wavelength emitted from the light emitting element is incident on the first waveguide, transmitted through the filter film from the second waveguide, coupled to the fiber with a filter, and sent to the transmission path, Light of the element emission wavelength sent from the transmission line,
The light passes through the filter film of the filter-equipped fiber, is coupled to the second waveguide, is branched into two by a Y-shaped branch, enters the light receiving element from the third waveguide, and is transmitted from the transmission path. The light of the transmission line wavelength obtained is reflected by the filter film of the fiber with a filter and is not coupled to the second waveguide, and the reflected light of the transmission line wavelength reflected by the filter film is A fiber-mounted fiber with a filter characterized in that reflected light of the wavelength of the transmission path is reflected by the fiber with a filter whose tip is polished obliquely so as not to return to the transmission path. Transmit / receive module. 2. The fiber mounting type with a filter according to claim 1, wherein the filter film is formed at a portion serving as a connection point between the fiber with a filter and the first to third waveguides. Optical transceiver module. 3. The fiber-mounted optical transceiver module with a filter according to claim 1, wherein the filter film is formed by vapor deposition in advance on the tip of the fiber with a filter. 4. The abutting slit is formed obliquely in a horizontal direction in accordance with a polishing angle of a tip portion of the fiber with a filter. A fiber-mounted optical transmission / reception module with a filter as described in the above. 5. The abutting slit is formed obliquely at a predetermined angle with respect to a vertical direction of the optical waveguide substrate in accordance with a polishing angle of a tip portion of the fiber with a filter. The fiber-mounted optical transceiver module with a filter according to any one of claims 1 to 3. 6. The fiber with a filter is fixed in a state where the slit for abutment is positioned by a V-groove and the slit for abutment in a state of being adjusted to a polishing angle of a tip portion of the fiber with a filter. 6. The fiber-mounted optical transceiver module with a filter according to claim 5, wherein the optical transceiver module is formed so as to be inclined to the side of the fiber fixing substrate to be formed. 7. The abutting slit is formed so as to be inclined toward the light emitting element and the light receiving element in a state in which the slit for abutment is adjusted to a polishing angle of a tip portion of the fiber with a filter. A fiber-mounted optical transceiver module with a filter according to claim 5. 8. The light receiving element carrier is mounted on a light receiving element carrier instead of on an optical waveguide substrate, and the light emitted from the third waveguide is incident on the light receiving element. The fiber-mounted optical transceiver module with a filter according to any one of claims 1 to 3, further comprising: