JP2016130813A - Optical receiver module, optical transmitter module, multiplexer, and demultiplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical transmitter module, an optical receiver module, a demultiplexer, and a multiplexer for achieving package size reduction.SOLUTION: A demultiplexer 121 has: a plurality of bandpass filters 1211a to 1211d each of which transmits an optical signal having a wavelength which is any one of different wavelengths and which reflects wavelengths other than the one wavelength, the bandpass filters 1211a to 1211d being disposed to be aligned; a reflection mirror 1212 which causes an optical signal which has been reflected or transmitted by each of the bandpass filters 1211b and 1211c between the bandpass filter on one end and the bandpass filter on the other end to be reflected by the adjacent bandpass filter; and reflection mechanisms 1214a and 1214b each causing an optical signal which has been reflected or transmitted by the bandpass filter on the one end to be reflected by the bandpass filter on the other end.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a demultiplexer that demultiplexes a wavelength-division multiplexed optical signal into a plurality of optical signals having different wavelengths, an optical receiver module that includes the demultiplexer, and an optical signal that combines optical signals of a plurality of wavelengths. The present invention relates to a wave resonator and an optical transmission module including the multiplexer.

  The optical transceiver is used for Internet communication using an optical fiber, and includes an optical transmission module that converts an electrical signal into an optical signal and an optical reception module that converts an optical signal into an electrical signal. The optical transmission module and the optical reception module are arranged side by side in the optical transceiver.

  In recent years, the standards for optical transceivers for 100G have been reduced in size, such as CFP, CFP2, and CFP4. With the miniaturization of the optical transceiver, it is necessary to reduce the size of the mounted optical transmission module and optical reception module. An optical receiving module mounted on an optical transceiver is a demultiplexer that demultiplexes an optical signal (hereinafter referred to as a wavelength multiplexed optical signal) obtained by wavelength division multiplexing (WDM) of optical signals having a plurality of wavelengths. And an EO converter that converts the demultiplexed optical signal into an electric signal (for example, Patent Document 1).

  In the duplexer described in Patent Document 1, a plurality of bandpass filters and reflection mirrors arranged in a line in a package are arranged in parallel. The duplexer described in Patent Document 1 allows wavelength-multiplexed optical signals to enter from a bandpass filter disposed at one end of a plurality of bandpass filters, and wavelength multiplexes between the plurality of bandpass filters and the reflection mirror. The reflected optical signal is reflected alternately. Each bandpass filter transmits an optical signal having one wavelength among a plurality of wavelengths and reflects an optical signal other than the transmitted optical signal. Therefore, the duplexer described in Patent Document 1 sequentially reflects the wavelength multiplexed optical signal by all the bandpass filters from the bandpass filter arranged at one end to the bandpass filter arranged at the other end. The optical signal can be demultiplexed into optical signals having different wavelengths.

JP 2013-125045 A

  However, the optical receiving module described in Patent Document 1 requires a wavelength multiplexed optical signal to be incident from a bandpass filter arranged at one end among a plurality of bandpass filters arranged in a line. The gap between the incident position where the wavelength multiplexed optical signal is incident on the filter and the center position of the branching filter becomes large, and there is a space (hereinafter referred to as a dead space) in which no branching filter or EO converter exists in the package. Occur. Therefore, there is a problem that the duplexer protrudes in the width direction of the package by the amount of the dead space, and the width of the optical receiving module is increased.

  Also, with respect to the optical transmission module, since a wavelength division multiplexed optical signal of a plurality of wavelengths is wavelength-multiplexed using a multiplexer having the same configuration as the above-described duplexer, the wavelength multiplexed optical signal is emitted from the duplexer. The deviation between the position and the center position of the duplexer becomes large, and a dead space is generated inside the package. Therefore, there is a problem that the width of the optical transmission module is increased.

  An optical receiver module, an optical transmitter module, a multiplexer, and a demultiplexer according to the present invention are made in order to solve the above-described problems, and an incident position or an output position and a demultiplexing of a wavelength multiplexed optical signal. An object of the present invention is to reduce a dead space in a package by reducing a deviation from the center position of the filter and the multiplexer.

  An optical receiver module according to the present invention includes a package into which a wavelength multiplexed optical signal including optical signals having a plurality of different wavelengths is incident, and the wavelength multiplexed optical signal that is disposed in the package and has different wavelengths. In an optical receiving module comprising: a demultiplexer that demultiplexes into a plurality of optical signals; and an OE converter that is disposed in the package and converts the optical signal demultiplexed by the demultiplexer into an electrical signal. The duplexer transmits a light signal having any one of the different wavelengths, reflects an optical signal having a wavelength other than the any one wavelength, and is arranged in a line. And an optical signal reflected by a band-pass filter between the band-pass filter at one end and the band-pass filter at the other end is reflected from the optical signal. A reflection mirror that reflects to a bandpass filter adjacent to the second pass filter, and a reflection mechanism that reflects an optical signal reflected by the bandpass filter at one end to the bandpass filter at the other end. The wavelength-multiplexed optical signal is disposed so as to be incident on a band-pass filter between the certain band-pass filter and the band-pass filter at the other end.

  The duplexer of the present invention is a duplexer that receives a wavelength multiplexed optical signal including optical signals having a plurality of different wavelengths and demultiplexes the wavelength multiplexed optical signal into a plurality of optical signals having different wavelengths. A plurality of band-pass filters that transmit an optical signal having any one of the different wavelengths and reflect an optical signal having a wavelength other than any one of the different wavelengths and arranged side by side; A reflection mirror that reflects an optical signal reflected by a bandpass filter between the bandpass filter and the bandpass filter at the other end to a bandpass filter adjacent to the bandpass filter that reflected the optical signal; A reflection mechanism for reflecting the optical signal reflected by the bandpass filter at one end to the bandpass filter at the other end, and The wavelength-multiplexed optical signal to the band-pass filter is between the band-pass filter at the command pass filter and the other end is characterized in that it is arranged to be incident.

An optical transmission module of the present invention includes a package into which an electric signal is incident, an EO conversion unit that is disposed in the package and converts the electric signal into a plurality of optical signals having different wavelengths,
An optical transmission module comprising: a multiplexer that multiplexes a plurality of optical signals having different wavelengths converted by the EO conversion unit and generates a wavelength multiplexed optical signal including optical signals having a plurality of different wavelengths. The multiplexer transmits a light signal having any one of the different wavelengths and reflects an optical signal having a wavelength other than the any one of the different wavelengths, and a plurality of bandpasses arranged side by side. A filter, a reflection mechanism for transmitting an optical signal having any one of the different wavelengths by a bandpass filter at one end, and reflecting the transmitted optical signal to the bandpass filter at the end; An optical signal transmitted and reflected by a band pass filter between the band pass filter at the other end and the band pass filter at the other end. And a reflection mirror that reflects a bandpass filter adjacent to the bandpass filter that transmits and reflects the optical signal, and is between the bandpass filter at one end and the bandpass filter at the other end. The wavelength-multiplexed optical signal transmitted and reflected by the bandpass filter is arranged to be emitted to the outside.

  The multiplexer according to the present invention is a multiplexer that multiplexes a plurality of optical signals having different wavelengths to generate a wavelength-multiplexed optical signal including optical signals having a plurality of different wavelengths. A plurality of bandpass filters that transmit an optical signal having one wavelength and reflect an optical signal having a wavelength other than any one of the wavelengths, and are arranged side by side; and any one of the different wavelengths A reflection mechanism that reflects the transmitted optical signal to a band-pass filter at the other end, and the band-pass filter at the other end and the band at the other end. The optical signal transmitted and reflected by the band pass filter between the optical filter and the pass filter are adjacent to the band pass filter that transmits and reflects the optical signal. A reflection mirror that reflects to the band-pass filter, and the wavelength-multiplexed optical signal transmitted and reflected by the band-pass filter between the band-pass filter at one end and the band-pass filter at the other end It is arranged to be emitted to the outside.

  Since the optical receiver module, the optical transmitter module, the multiplexer, and the duplexer according to the present invention include a reflection mechanism that reflects the optical signal reflected by the bandpass filter at one end to the bandpass filter at the other end, Deviation between the incident position or the emission position of the multiplexed optical signal and the center position of the duplexer or multiplexer can be reduced, and the dead space in the package can be reduced. Therefore, the optical transmission module and the optical reception module can be reduced in size, and the optical transceiver can be reduced in size.

FIG. 3 is a perspective view of the optical receiving module according to the first embodiment. FIG. 3 is a perspective view of the duplexer according to the first embodiment. FIG. 3 is a top view of the duplexer according to the first embodiment. FIG. 3 is a top view of the optical receiving module according to the first embodiment. FIG. 6 is a perspective view of an optical transmission module according to Embodiment 2. FIG. 6 is a top view of the optical transmission module according to the second embodiment. The top view of the conventional optical receiver module.

Embodiment 1 FIG.
Hereinafter, the configuration of the optical receiver module according to Embodiment 1 will be described with reference to FIG. 1 is a perspective view of an optical receiver module according to Embodiment 1. FIG. In FIG. 1, the optical receiving module 1 includes a connector unit 11, a package 12, a terminal unit 13, and a flexible substrate 14.

  The connector part 11 connects an optical fiber (not shown) and a package 12 described later. The connector portion 11 has one end connected to an optical fiber (not shown) and the other end connected to the package 12. The connector unit 11 receives an optical signal obtained by wavelength division multiplexing of a plurality of optical signals having different wavelengths (hereinafter referred to as a wavelength multiplexed optical signal) from an optical fiber, and the wavelength multiplexed optical signal is input to the connector unit. 11 is collimated or pseudo-collimated by a lens (not shown) inside 11 to make parallel light, and this wavelength multiplexed optical signal is made incident in the package 12. The wavelength here refers to a wavelength band.

  The package 12 includes a duplexer 121, a condensing optical system 122, a light receiving element 123, and an amplifier 124 therein. The demultiplexer 121 demultiplexes the wavelength multiplexed optical signal incident through the connector unit 11 into a plurality of optical signals having different wavelengths. The condensing optical system 122 condenses a plurality of optical signals demultiplexed by the demultiplexer 121 on a light receiving element 123 described later. The light receiving element 123 photoelectrically converts the collected optical signal. The amplifier 124 amplifies the photoelectrically converted electrical signal and outputs it to the terminal unit 13. The condensing optical system 122 and the light receiving element 123 are expressed as an OE converter.

  The terminal portion 13 is connected to the surface opposite to the surface to which the connector portion 11 of the package 12 is connected. Further, the terminal unit 13 connects the package 12 and the flexible substrate 14, and outputs an electrical signal photoelectrically converted by the light receiving element 123 to the flexible substrate 14. The flexible board 14 outputs an electrical signal to a transceiver board (not shown).

  Next, the configuration of the duplexer 121 according to the present embodiment will be described in detail. FIG. 2 is a perspective view of the duplexer according to the first embodiment. In FIG. 2, the duplexer 121 includes band-pass filters 1211a to 1211d, a reflection mirror 1212, a filter block 1213, and reflection mirrors 1214a and 1214b.

  The filter block 1213 has an octahedral shape, the bottom surface is fixed to the package 12, and a plurality of bandpass filters 1211a to 1211d, a reflection mirror 1212, and reflection mirrors 1214a and 1214b, which will be described later, are fixed at predetermined positions. Specifically, in the filter block 1213, band pass filters 1211a to 1211d are arranged in a line on one surface, and a reflection mirror 1212 is arranged on a surface parallel to the surface on which the band pass filters 1211a to 1211d are arranged. The reflection mirrors 1214a and 1214b are provided on surfaces (edge surfaces a and b described later) adjacent to the surface on which the reflection mirror 1212 is disposed. In the optical receiver module 1 according to the present embodiment, the filter block 1213 fixes components such as the bandpass filters 1211a to 1211d, the reflection mirror 1212, and the reflection mirrors 1214a and 1214b. These components may be directly fixed to the bottom surface of the package 12 with an adhesive or the like without using them. In addition, the arrangement here means that a plurality of band-pass filters 1211a to 1211d, a reflecting mirror 1212, and reflecting mirrors 1214a and 1214b are bonded to a filter block 1213, and a plurality of band-pass filters 1211a to 1211d and reflecting mirrors. 1212 and reflecting mirrors 1214a and 1214b are directly bonded to the package 12.

  The band-pass filters 1211a to 1211d transmit only an optical signal of any one of a plurality of wavelengths included in the wavelength multiplexed optical signal, and reflect the optical signals of other wavelengths. Therefore, each of the bandpass filters 1211a to 1211d transmits optical signals having different wavelengths. The same number of bandpass filters 1211a to 1211d as the number of optical signals of a plurality of wavelengths included in the wavelength multiplexed optical signal are provided and fixed in a line on one surface of the filter block 1213. This embodiment will be described using an example in which there are four types of wavelengths of optical signals included in a wavelength multiplexed optical signal. Accordingly, four band pass filters 1211a to 1211d are provided.

  For example, when the wavelength of the optical signal included in the wavelength multiplexed optical signal is four types of wavelengths λ1 to λ4, the bandpass filter 1211a transmits the optical signal having the wavelength λ1, and the other wavelengths λ2, λ3, and λ4. Reflects the wavelength multiplexed optical signal. The bandpass filter 1211b transmits the optical signal having the wavelength λ2, and reflects the wavelength multiplexed optical signals having the other wavelengths λ1, λ3, and λ4. The bandpass filter 1211c transmits the optical signal having the wavelength λ3 and reflects the wavelength multiplexed optical signals having the wavelengths λ1, λ2, and λ4. Further, the bandpass filter 1211d transmits the optical signal having the wavelength λ4 and reflects the wavelength multiplexed optical signals having the wavelengths λ1, λ2, and λ3.

  The band pass filters 1211a to 1211d are arranged in a line at a predetermined interval. This predetermined interval corresponds to the interval between the optical signals emitted from the bandpass filters 1211a to 1211d. The interval between the optical signals corresponds to the interval between the light receiving elements 123, and the interval between the light receiving elements 123 corresponds to the interval between input terminals (not shown) of the amplifier 124. Therefore, the arrangement interval of the bandpass filters 1211a to 1211d is determined in accordance with the interval between the input terminals of the amplifier 124. Therefore, the length of the band-pass filters 1211a to 1211d in the width direction of the package 12 is limited by the interval between the input terminals of the amplifier 124. However, the lengths of the bandpass filters 1211a to 1211d in the height direction can be formed longer in the height direction than in the width direction because there is no restriction on the interval between the input terminals of the amplifier 124. In this way, when the length in the height direction is longer than the length in the width direction of the bandpass filters 1211a to 1211d, the length in the width direction of the bandpass filters 1211a to 1211d is equal to the height direction. In comparison, the adhesion area between the bandpass filters 1211a to 1211d and the filter block 1213 can be increased. Therefore, the adhesive strength between the bandpass filters 1211a to 1211d and the filter block 1213 can be increased.

  The filter block 1213 and the bandpass filters 1211a to 1211d are preferably made of the same kind of glass material or glass having a linear expansion. As described above, the band-pass filters 1211a to 1211d and the filter block 1213 are made of the same type or glass having a similar linear expansion, so that the band-pass filters 1211a to 1211d and the filter block against the environmental temperature fluctuation of the optical reception module 1 are obtained. The stress at the boundary surface caused by the difference in thermal linear expansion from 1213 can be suppressed, and the peeling of the adhesive and the displacement of the filter can be reduced.

  The reflection mirror 1212 reflects all of the optical signals of a plurality of wavelengths included in the wavelength multiplexed optical signal. For example, when the wavelength of the optical signal included in the wavelength multiplexed optical signal is four types of wavelengths λ1 to λ4, the reflection mirror 1212 reflects the optical signal having the wavelengths λ1 to λ4. The reflection mirror 1212 is provided with a multilayer coating, a gold coating, and the like, and reflects an optical signal. The reflection mirror 1212 is provided in parallel with the band-pass filters 1211a to 1211d arranged in a line.

  The reflection mirrors 1214a and 1214b are provided on the edge surface a and the edge surface b adjacent to the surface on which the reflection mirror 1212 of the filter block 1213 is provided. For example, when the wavelengths of the optical signals included in the wavelength multiplexed optical signal are four types of wavelengths λ1 to λ4, the reflecting mirror 1212 reflects the optical signals of wavelengths λ1 to λ4. Similarly to the reflection mirror 1212, the reflection mirrors 1214a and 1214b are coated with a multilayer film and a gold coat and reflect all optical signals.

  The reflection mirrors 1214a and 1214b are preferably large enough to reflect 99% or more of light with respect to the beam size of the wavelength multiplexed optical signal. Since the reflection mirrors 1214a and 1214b have a sufficient size with respect to the beam size of the wavelength multiplexed optical signal, loss of the optical signal when the wavelength multiplexed optical signal is reflected by the reflection mirrors 1214a and 1214b. Can be reduced.

  The reflection mirrors 1214a and 1214b may be disposed in the package 12 so that at least the optical signal reflected by the bandpass filter 1211d at one end is reflected by the bandpass filter at the other end, but is incident on the bandpass filter 1211a. It is preferable that the incident angle of the optical signal is equal to the incident angle incident on the other bandpass filters 1211b to 1211d. By arranging so that the incident angle of the optical signal incident on the bandpass filter 1211a is equal to the incident angle of the optical signal incident on the other bandpass filter, it is emitted from all the bandpass filters 1211a to 1211d. The emission angles of a plurality of different optical signals can be made uniform, and the amplifier 124 can be made to correspond to the amplifier 124 having a constant input terminal interval. The reflection mirrors 1214a and 1214b are collectively expressed as a reflection mechanism.

  Next, a series of flow until the demultiplexer 121 demultiplexes the wavelength multiplexed optical signal into a plurality of different optical signals will be described. FIG. 3 is a top view of the duplexer according to the first embodiment. In FIG. 3, the wavelength-multiplexed optical signal that has entered the package 12 from the connector unit 11 enters the area 1213 </ b> A on which the AR coating of the duplexer 121 is applied. At this time, it is assumed that the wavelength multiplexed optical signal is a wavelength division multiplexed optical signal having a plurality of wavelengths λ1 to λ4. The wavelength multiplexed optical signal incident on the demultiplexer 121 first enters the bandpass filter 1211b and transmits only the optical signal having the wavelength λ2. The band pass filter 1211b reflects the optical signals having wavelengths λ1, λ3, and λ4 other than the wavelength λ2 to the reflection mirror 1212.

  The reflection mirror 1212 reflects the wavelength multiplexed optical signal including the optical signals having the wavelengths λ1, λ3, and λ4 reflected by the bandpass filter 1211b to the bandpass filter 1211c adjacent to the bandpass filter 1211b. The bandpass filter 1211c transmits the optical signal having the wavelength λ3 among the wavelengths λ1, λ3, and λ4, and reflects the wavelength multiplexed optical signal including the optical signals having the wavelengths λ1 and λ4 other than the wavelength λ3 to the reflection mirror 1212 again. .

  Similarly, the optical signals having the wavelengths λ1 and λ4 reflected by the reflecting mirror 1212 enter the bandpass filter 1211d at one end and transmit only the optical signal having the wavelength λ4. The optical signal having the wavelength λ1 is transmitted through the edge portion of the filter block 1213. It is reflected by the reflection mirror 1214b provided in b. At this time, the reflection mirror 1214b reflects the optical signal having the wavelength λ1 in the direction of the reflection mirror 1214a. Further, the optical signal having the wavelength λ1 is reflected by the reflection mirror 1214a and enters the bandpass filter 1211a at the other end. That is, the reflection mechanisms 1214a and 1214b reflect the optical signal reflected by the band-pass filter 1211d at one end to the band-pass filter 1211a at the other end. The band-pass filter 1211a transmits the optical signal having the wavelength λ1, thereby completing the demultiplexing of the wavelength multiplexed optical signal.

  In the above description of FIG. 3, the example in which the wavelength multiplexed optical signal first enters the bandpass filter 1211b is shown, but the present invention is not limited to this, and the wavelength multiplexed optical signal may be configured to enter from the bandpass filter 1211c. The wavelength multiplexed optical signal first incident on the bandpass filter 1211c is reflected by the bandpass filter 1211c, and then reflected by the reflection mirror 1212, the bandpass filter 1211d, the reflection mirror 1214b, the reflection mirror 1214a, the bandpass filter 1211a, and the reflection mirror. By sequentially entering 1212 and the bandpass filter 1211b, the light is demultiplexed into a plurality of optical signals having different wavelengths. As described above, when the duplexer 121 is configured so that the wavelength multiplexed optical signal is incident from the bandpass filter 1211c, the reflection mirror 1212 is also arranged on the optical axis of the optical signal reflected by the bandpass filter 1211a. Need to be done. Further, the reflection mirror 1212 is not provided on the optical axis of the wavelength multiplexed light incident on the band pass filter 1211c.

  In the description of FIG. 3, the wavelength multiplexed optical signal is incident on the bandpass filter 1211b, then reflected by the reflection mirror 1212 and incident on the adjacent bandpass filter 1211c. It may be configured to enter the adjacent bandpass filter 1211a. The wavelength multiplexed optical signal reflected by the reflecting mirror 1212 and incident on the bandpass filter 1211a is reflected by the bandpass filter 1211a and reflected from the bandpass filter 1211a at one end to the bandpass filter 1211b at the other end. Subsequently, the wavelength multiplexed optical signal is demultiplexed into optical signals having a plurality of different wavelengths by being incident on the band pass filter 1211d, the reflection mirror 1212, and the band pass filter 1211c. As described above, even when the duplexer 121 is configured such that the wavelength multiplexed optical signal is reflected by the reflection mirror 1212 and incident on the bandpass filter 1211a, the reflection mirror 1212 is reflected by the bandpass filter 1211b. It is also necessary to be disposed on the optical axis of the optical signal. In addition, it is necessary to adjust the angle at which the duplexer 121 is arranged so that the wavelength multiplexed optical signal first incident on the bandpass filter 1211b is incident on the bandpass filter 1211a via the reflection mirror 1212. . Further, the reflection mirror 1212 is not provided on the optical axis of the wavelength multiplexed optical signal incident on the band pass filter 1211b.

  In any case, a wavelength-multiplexed optical signal is incident from a bandpass filter 1211b or 1211c other than the bandpass filters 1211a and 1211d at both ends, and the bandpass filter 1211a or 1211d at one end is bandpassed from the bandpass filter 1211a or 1211d at one end by the reflecting mechanisms 1214a and 1214b. If the wavelength-multiplexed optical signal is incident on all the bandpass filters by making the wavelength-multiplexed optical signal incident on the filter 1211d or 1211a, it can be demultiplexed into a plurality of optical signals having different wavelengths.

  In this embodiment, this reflection mechanism includes two reflection mirrors 1214a and 1214b. However, an optical signal reflected by one end of the plurality of bandpass filters 1211a to 1211d is reflected by the bandpass filter 1211d. If the angle of the reflection mirror 1214b is adjusted so as to be reflected by the band-pass filter 1211a at the other end, the reflection mechanism may include one of the reflection mirrors 1214b. By using one of the reflection mirrors 1214b, the number of parts can be reduced, and the production cost of the duplexer 121 can be reduced. The reflection mechanism may include two or more reflection mirrors.

Note that an AR coating (Anti Reflection Coating) is applied to the region 1213A of the filter block 1213 where the wavelength-multiplexed optical signal is incident, so that transmission loss can be suppressed.
The incident angle at which the wavelength multiplexed optical signal enters the bandpass filter 1211b is determined according to the interval between the bandpass filters 1211a to 1211d and the interval between the bandpass filters 1211a to 1211d and the reflection mirror 1212. When the bandpass filters 1211a to 1211d and the reflection mirror 1212 are parallel, the incident angle at which the wavelength multiplexed optical signal is incident on the bandpass filter 1211b increases as the distance between the bandpass filters 1211a to 1211d increases. Further, as the distance between the bandpass filters 1211a to 1211d and the reflection mirror 1212 increases, the incident angle at which the wavelength multiplexed optical signal enters the bandpass filter 1211b decreases.

  The angles of the edge portions a and b, that is, the arrangement angle of the reflection mirrors 1214a and 1214b with respect to the reflection mirror 1212 are the incident angle at which the wavelength multiplexed optical signal is incident on the bandpass filter 1211b, and the bandpass filters 1211a to 1211d. The optical signal reflected by the bandpass filter 1211d is adjusted to be reflected by the bandpass filter 1211a according to the interval and the angle between the bandpass filters 1211a to 1211d and the reflection mirror 1212.

  The angle at which the wavelength multiplexed optical signal is incident on the bandpass filter 1211b is adjusted by adjusting the angle at which the filter block 1213 is disposed in the package 12 or the angle of the surface of the filter block 1213 on which the bandpass filter 1211b is disposed. It is determined.

  FIG. 4 is a top view of the optical receiver module according to the first embodiment. As shown in FIG. 4, the optical receiver module 1 according to the present embodiment reflects the optical signal reflected by the band-pass filter at one end to the band-pass filter at the other end. Wavelength multiplexed optical signals can be first incident from bandpass filters 1211b other than 1211a and 1211d. That is, the duplexer 121 can be arranged so that the bandpass filter 1211b exists on the optical axis (broken arrow A) of the wavelength multiplexed optical signal incident at the center position of the connector portion 11. That is, it is possible to reduce the deviation between the incident position (corresponding to the position of the dashed arrow A) where the wavelength multiplexed optical signal enters the duplexer 121 and the center position (broken line B) of the duplexer 121.

  On the other hand, FIG. 7 is a top view of a conventional optical receiver module. The conventional duplexer 121c of the optical receiving module does not include a reflection mechanism that reflects the optical signal reflected by the band-pass filter at one end to the band-pass filter at the other end, and thus the band-pass filter 1211a disposed at one end. Therefore, it is necessary to make the wavelength multiplexed optical signal incident. Therefore, in the conventional optical receiver module, the deviation between the center position of the connector portion 11 and the center position of the duplexer 121c becomes large. Therefore, a dead space A is generated between the duplexer 121c and the package 12, and the width of the package 12 is increased. Therefore, the optical transmitter module according to the first embodiment can bring the duplexer 121 closer to the center of the package 12 than the conventional optical receiver module shown in FIG. The deviation between the incident position where the multiplexed optical signal enters and the center position of the duplexer 121 can be reduced. Thereby, the dead space A in the package 12 can be reduced.

  As described above, the duplexer and the optical receiver module according to the present embodiment include the reflection mechanism that reflects the optical signal reflected by the band-pass filter at one end to the band-pass filter at the other end. The deviation between the signal incident position and the center position of the duplexer can be reduced, and the dead space in the package can be reduced. Therefore, it is possible to reduce the size of the optical receiving module, and it is possible to reduce the size of the optical transceiver.

  In the present embodiment, the example in which the number of the band-pass filters 1211a to 1211d is four has been described, but any number that allows light to enter from band-pass filters other than the band-pass filters at both ends may be used. Specifically, it may be three or more.

  The wavelength of the optical signal reflected by the reflection mirror 1212 only needs to reflect at least an optical signal having a wavelength included in the wavelength multiplexed optical signal.

  In the description of the present embodiment, the demultiplexer 121 first causes the wavelength-multiplexed optical signal to enter the bandpass filter 1211b. However, the present invention is not limited to this. For example, other than the bandpass filters 1211a and 1211d at both ends. May be incident on the bandpass filter 1211c. That is, the wavelength-multiplexed optical signal may be incident on one of the bandpass filters 1211b and 1211c sandwiched between the bandpass filters 1211a and 1211d at both ends.

Embodiment 2. FIG.
Hereinafter, the optical transmission module according to Embodiment 2 will be described with reference to FIG. FIG. 5 is a perspective view of the optical transmission module according to the second embodiment. In the description of FIG. 5, components corresponding to the configuration of the optical receiver module according to Embodiment 1 are denoted by the same reference numerals and description thereof is omitted.

  The optical transmission module 2 according to Embodiment 2 includes a multiplexer 121b, a lens 122b, and an EO converter 123b inside the package 12. The EO converter 123b converts the electrical signal input from the terminal unit 13 into an optical signal, and emits a plurality of optical signals having different wavelengths. The lens 122b converts the plurality of optical signals having different wavelengths emitted from the EO converter 123b into parallel light. The multiplexer 121b multiplexes a plurality of optical signals having different wavelengths to obtain a wavelength multiplexed optical signal. The combined wavelength multiplexed optical signal is collected by a lens (not shown) inside the connector unit 11 and is incident on the optical fiber via the connector 11.

  Next, a series of flows in which the multiplexer 121b according to the present embodiment combines a plurality of optical signals having different wavelengths will be described with reference to FIG. FIG. 6 is a top view of the multiplexer according to the second embodiment. The configuration of the multiplexer 121b is the same as that of the duplexer 121 shown in FIG. In the following description, the wavelength multiplexed optical signal emitted from the optical transmission module 2 will be described using an example in which the number of wavelengths of the optical signal is four.

  In FIG. 6, optical signals having different wavelengths λ1 to λ4 that are first emitted from the EO converter 123b are incident on a plurality of bandpass filters 1211a, 1211b, 1211c, and 1211d via a lens 122b. Specifically, an optical signal having a wavelength λ1 is incident on the bandpass filter 1211a, an optical signal having a wavelength λ2 is incident on the bandpass filter 1211b, and an optical signal having a wavelength λ3 is incident on the bandpass filter 1211c. An optical signal having a wavelength λ4 is incident on the bandpass filter 1211d. The optical signal having the wavelength λ4 incident on the bandpass filter 1211d is reflected by the reflection mirror 1214b to the reflection mirror 1214a and reflected by the reflection mirror 1214a to the bandpass filter 1211a. That is, the reflection mechanisms 1214a and 1214b reflect the optical signal transmitted and reflected by the bandpass filter 1211d to the bandpass filter 1211a. The optical signal having the wavelength λ4 reflected by the bandpass filter 1211a is reflected in the direction of the reflection mirror 1212. At this time, the optical signal having the wavelength λ4 reflected by the bandpass filter 1211a is combined with the optical signal having the wavelength λ1 that has passed through the bandpass filter 1211a and entered the filter block 1213.

  Subsequently, the multiplexed wavelength-multiplexed optical signal having wavelengths λ1 and λ4 is reflected by the reflection mirror 1212 to the bandpass filter 1211b. The band pass filter 1211 b reflects the wavelength multiplexed optical signals having the wavelengths λ 1 and λ 4 to the reflection mirror 1212. The wavelength multiplexed optical signals having the wavelengths λ1 and λ4 reflected by the bandpass filter 1211b are combined with λ2 transmitted through the bandpass filter 1211b and incident on the filter block 1213.

  Similarly, the reflection mirror 1212 reflects the combined wavelength-multiplexed optical signals having wavelengths λ1, λ2, and λ4 to the bandpass filter 1211c. The bandpass filter 1211 c reflects the wavelength multiplexed optical signals having wavelengths λ1, λ2, and λ4 to the region 1213A of the filter block 1213. The wavelength multiplexed optical signals having the wavelengths λ1, λ2, and λ4 reflected by the bandpass filter 1211c are combined with the optical signal having the wavelength λ3 that has passed through the bandpass filter 1211c. The wavelength-multiplexed optical signals having wavelengths λ1 to λ4 are emitted to the connector unit 11 through the region 1213A of the filter block 1213 and are emitted to the optical fiber connected to the connector unit 11.

  As described above, the multiplexer 121b includes the reflection mechanism including the reflection mirrors 1214a and 1214b. On the optical axis of the optical signal passing through.

  As described above, the multiplexer and the optical transmission module according to the present embodiment include the reflection mechanism that reflects the optical signal reflected by the band-pass filter at one end to the band-pass filter at the other end. Deviation between the signal emission position and the center position of the multiplexer can be reduced, and the dead space in the package can be reduced. Therefore, the optical transmission module can be reduced in size, and the optical transceiver can be reduced in size.

  The emission position of the wavelength multiplexed optical signal is the optical axis of the optical signal transmitted by the band pass filter 1211c and the optical signal reflected by the band pass filter 1211c. The emission position may be on any of the optical axes 1211b and 1211c as long as it is on the optical axis of the optical signal reflected and transmitted by the bandpass filters sandwiched between the bandpass filters 1211a and 1211d at both ends.

  In the case of the optical receiver module 1 shown in the first embodiment, the incident wavelength band is generally specified by the standard, but the wavelength includes an optical signal having a wavelength other than the specified wavelength band. A multiplexed optical signal may be incident. The optical reception module 1 needs to prevent optical signals having wavelengths other than the specified wavelength band from being transmitted through any of the bandpass filters 1211a to 1211d. Therefore, the number of the bandpass filters 1211a to 1211d is It is necessary to provide a number corresponding to the number of wavelengths of the wavelength multiplexed optical signal to be waved.

  On the other hand, in the case of the optical transmission module 2 according to the present embodiment, the wavelength of the optical signal emitted from the EO converter 123b is an oscillation wavelength of a light emitting element (not shown) and is known on the optical transmission module 2 side. Therefore, the number of bandpass filters corresponding to a plurality of wavelengths is not necessarily required. Specifically, the bandpass filter 1211d that does not need to reflect an optical signal having a wavelength other than the optical signal having the wavelength λ4 to be transmitted in the multiplexer 121b is a member in which an AR coating is applied to the glass (hereinafter referred to as a glass member). )) Can be substituted. The glass member has the same thickness as the bandpass filters 1211a to 1211c.

  The optical transmission module 2 may be provided with three bandpass filters 1211a to 1211c by removing the bandpass filter 1211d. That is, the optical transmission module 2 is provided with a band-pass filter 1211a to 1211c that is one less than the number of wavelengths of the optical signal emitted from the EO converter 123b, and the space of the band-pass filter 1211d (hereinafter referred to as an incident space). In this case, the filter block 1213 may be AR coated. As described above, the production cost of the multiplexer 121b can be reduced by using the bandpass filter 1211d as a glass member or removing the bandpass filter 1211d to form an incident space.

  DESCRIPTION OF SYMBOLS 1 Optical receiver module, 2 Optical transmitter module, 11 Connector part, 12 Package, 13 Terminal part, 14 Flexible substrate, 111 lens, 121 splitter, 121b multiplexer, 122 Condensing optical system, 122b lens, 123 Light receiving element , 123b EO converter, 124 amplifier, 1211a to 1211d bandpass filter, 1212 reflection mirror, 1213 filter block, 1214a, 1214b reflection mirror

Claims (12)

A package on which a wavelength multiplexed optical signal including an optical signal having a plurality of different wavelengths is incident;
A demultiplexer arranged in the package and demultiplexing the incident wavelength multiplexed optical signal into a plurality of optical signals having different wavelengths;
In an optical receiving module comprising: an OE conversion unit arranged in the package and converting an optical signal demultiplexed by the demultiplexer into an electric signal;
The duplexer is
A plurality of band-pass filters that transmit an optical signal having any one of the different wavelengths and reflect an optical signal having a wavelength other than any one of the wavelengths;
An optical signal reflected by a bandpass filter between the bandpass filter at one end and the bandpass filter at the other end is reflected to a bandpass filter adjacent to the bandpass filter that reflected the optical signal. A reflective mirror,
A reflection mechanism that reflects the optical signal reflected by the bandpass filter at one end to the bandpass filter at the other end, and
An optical receiver module, wherein the wavelength-multiplexed optical signal is arranged to be incident on a band-pass filter between the band-pass filter at one end and the band-pass filter at the other end. The optical receiver module according to claim 1, further comprising a filter block that fixes the plurality of bandpass filters, the reflection mirror, and the reflection mechanism to the package. The bandpass filter is
The optical receiver module according to claim 2, wherein a length in the height direction of the package is longer than a length in the width direction of the package. The filter block is
The optical receiver module according to claim 2, wherein the optical receiver module is made of the same material as the plurality of bandpass filters. In a demultiplexer that receives a wavelength-multiplexed optical signal including optical signals having a plurality of different wavelengths and demultiplexes the wavelength-multiplexed optical signal into a plurality of optical signals having different wavelengths,
A plurality of band-pass filters that transmit an optical signal having any one of the different wavelengths and reflect an optical signal having a wavelength other than any one of the wavelengths;
An optical signal reflected by a bandpass filter between the bandpass filter at one end and the bandpass filter at the other end is reflected to a bandpass filter adjacent to the bandpass filter that reflected the optical signal. A reflective mirror,
A reflection mechanism for reflecting the optical signal reflected by the bandpass filter at one end to the bandpass filter at the other end, and between the bandpass filter at one end and the bandpass filter at the other end A demultiplexer, wherein the wavelength-multiplexed optical signal is arranged so as to be incident on a bandpass filter in A package into which an electrical signal is incident;
An EO converter disposed in the package for converting the electrical signal into a plurality of optical signals having different wavelengths;
An optical transmission module comprising: a multiplexer that multiplexes a plurality of optical signals having different wavelengths converted by the EO conversion unit and generates a wavelength multiplexed optical signal including optical signals having a plurality of different wavelengths. ,
The multiplexer is
A plurality of band-pass filters that transmit an optical signal having any one of the different wavelengths and reflect an optical signal having a wavelength other than any one of the wavelengths;
A reflection mechanism that transmits an optical signal having one of the different wavelengths through a band-pass filter at one end and reflects the transmitted optical signal to the band-pass filter at the other end;
An optical signal transmitted and reflected by a bandpass filter between the bandpass filter at one end and the bandpass filter at the other end is converted into a bandpass filter that transmits and reflects the optical signal. A reflection mirror that reflects to an adjacent bandpass filter;
The wavelength multiplexed optical signal transmitted and reflected by the band pass filter between the band pass filter at one end and the band pass filter at the other end is arranged to be emitted to the outside. An optical transmitter module. Of the plurality of bandpass filters, the bandpass filter at one end is
The optical transmission module according to claim 6, wherein the optical transmission module is replaced with a glass that transmits optical signals having different wavelengths. The optical transmission module according to claim 6, wherein the band-pass filter at one end is removed from the plurality of band-pass filters. 9. The optical transmission according to claim 6, further comprising: a filter block that fixes the plurality of bandpass filters, the reflection mirror, and the reflection mechanism to the package. module. The bandpass filter is
The optical transmission module according to claim 9, wherein a length in the height direction of the package is longer than a length in the width direction of the package. The filter block is
The optical transmission module according to claim 9 or 10, wherein the optical transmission module is made of the same material as the plurality of band-pass filters. In a multiplexer that combines a plurality of optical signals having different wavelengths to generate a wavelength multiplexed optical signal including optical signals having a plurality of different wavelengths,
A plurality of band-pass filters that transmit an optical signal having any one of the different wavelengths and reflect an optical signal having a wavelength other than any one of the wavelengths;
A reflection mechanism that transmits an optical signal having one of the different wavelengths through a bandpass filter at one end and reflects the transmitted optical signal to a bandpass filter at the other end;
An optical signal transmitted and reflected by a bandpass filter between the bandpass filter at one end and the bandpass filter at the other end is converted into a bandpass filter that transmits and reflects the optical signal. A reflection mirror that reflects to an adjacent bandpass filter;
The wavelength multiplexed optical signal transmitted and reflected by the band pass filter between the band pass filter at one end and the band pass filter at the other end is arranged to be emitted to the outside. Characteristic multiplexer.

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