JP4873153B2 - Optical module and optical communication system - Google Patents

Description

  The present invention relates to an optical module and an optical communication system.

  One of the currently used optical communication technologies is a wavelength division multiplexing (WDM) wavelength division multiplexing system. This is a method in which the communication capacity can be increased by the number of multiplexed signal lights by sending a plurality of signal lights having different wavelengths through one optical fiber. By using this method, the communication capacity can be increased without newly installing an optical fiber. Until now, the above technology has been used only for trunk systems such as between NTT base stations, but with the spread of the Internet in recent years, FTTH (Fiber To The Home) is used to install optical fiber in each home. Is underway. The introduction of the WDM system is also being studied in non-trunk systems such as in the home. The communication capacity required in a non-trunk system such as in the home is not so high as compared to the trunk system optical communication, but the cost of communication equipment is required to be reduced. Therefore, a CWDM (Coarse Wavelength Division Multiplex) method has been proposed as a method of reducing the cost while satisfying the required communication capacity of the WDM method in the trunk line system. Compared to the WDM system, the number of multiplexed signal lights is small, and the wavelength interval of the signal lights is wide. Since the number of signal lights to be multiplexed is small, the number of light sources such as semiconductor lasers can be reduced, and since the wavelength interval of the signal lights is wide, wavelength control is not required, and the cost can be reduced.

As a communication system using the CWDM system, a communication system 800 including an optical fiber 810, an optical multiplexer 830, and a plurality of light sources (laser diodes) 820 as shown in FIG. 11 has been proposed. The optical multiplexer 830 is an element in which an optical waveguide 832 made of, for example, silicon oxide is formed on a silicon substrate 834, and is an element that multiplexes a plurality of branched lights into one waveguide 832. Each of the plurality of light sources 820 is provided at a position corresponding to each of the waveguides 832 of the optical multiplexer 830, and the optical axes coincide with each other. n laser beams having different oscillation wavelengths λ emitted from n light sources 820 (lights having oscillation wavelengths λ1, λ2,..., λn) are coupled to one optical fiber 810 through an optical multiplexer 830. .
JP-A-3-268523 JP-A-57-24832

  The objective of this invention is providing the optical module and optical communication system which can reduce the frequency | count of optical axis alignment.

  Another object of the present invention is to provide an optical communication system capable of increasing communication capacity.

1. Optical Module The optical module of the present invention is
Including multiple light sources,
The optical axes of the plurality of light sources coincide with each other.

  In the optical module of the present invention, a plurality of light sources coincide with each other. For this reason, for example, a plurality of light sources can be optically aligned with the optical fiber only by aligning the optical module with the optical fiber. As a result, the number of times of optical axis alignment can be reduced, and manufacturing costs can be reduced and productivity can be improved.

  Further, according to the present invention, it is not necessary to couple a plurality of lights to an optical fiber using an optical multiplexer. For this reason, an optical multiplexer becomes unnecessary.

  The optical module of the present invention can take at least one of the following aspects.

  (A) A mode in which the wavelengths of light emitted from the plurality of light sources are set to be shorter as the light is emitted in the direction in which the light is emitted.

  In the case of this aspect, it is possible to suppress the light emitted from the light source from being absorbed by the intermediate light source.

  (B) A mode in which each of the plurality of light sources is a surface emitting semiconductor laser.

  In this case, the oscillation wavelength of each of the plurality of light sources is other than the reflection band of the adjacent light sources in the direction in which the light is emitted.

  In the case of this aspect, it is possible to prevent light emitted from a certain light source from being reflected by an adjacent light source.

(C) including a plurality of substrates;
Each of the plurality of light sources is provided on each of the corresponding plurality of substrates,
The plurality of substrates are stacked.

  In the case of this aspect, at least one of the plurality of substrates may be provided so as to protrude outward from an end portion of the adjacent substrate on one side. According to this, it is possible to provide a wiring for drawing out the electrode constituting the light source at the protruding portion, and it is easy to form the wiring.

(D) One of the two adjacent light sources is provided on one side of the substrate,
A mode in which the other light source is provided on the other side of the substrate.

  (E) A mode in which the plurality of substrates have a function of transmitting light emitted from the plurality of light sources.

2. 2. Optical Communication System 2.1 First Optical Communication System The first optical communication system of the present invention is
Optical fiber,
A plurality of light sources,
The plurality of light sources are arranged along the optical axis of the optical fiber.

  According to the optical communication system of the present invention, since the plurality of light sources are arranged along the optical axis of the optical fiber, it is not necessary to couple the plurality of lights to the optical fiber using an optical multiplexer. For this reason, an optical multiplexer becomes unnecessary.

  In the first optical communication system of the present invention, the wavelengths of the plurality of light sources can be increased as the distance from the optical fiber increases. Thereby, it can suppress that the light emitted from the light source is absorbed by the light source in the middle.

2.2 Second Optical Communication System The second optical communication system of the present invention is
Optical fiber,
Including the optical module of the present invention,
The optical fiber and the optical module have the same optical axis.

  In the second optical communication system of the present invention, the plurality of light sources of the optical module coincide with each other. For this reason, for example, a plurality of light sources can be optically aligned with the optical fiber only by aligning the optical module with the optical fiber. As a result, the number of times of optical axis alignment can be reduced, and manufacturing costs can be reduced and productivity can be improved.

  Further, according to the present invention, it is not necessary to couple a plurality of lights to an optical fiber using an optical multiplexer. For this reason, an optical multiplexer becomes unnecessary.

  In the second optical communication system of the present invention, the wavelength of the light source of the optical module may become longer as the distance from the optical fiber increases. Thereby, it can suppress that the light emitted from the light source is absorbed by the light source in the middle.

2.3 Third optical communication system The third optical communication system of the present invention
A plurality of optical modules of the present invention;
Including the optical fiber,
A plurality of light emitted from each of the plurality of optical modules is coupled to the optical fiber by an optical multiplexer.

  According to the third optical communication system of the present invention, since a plurality of optical modules are provided and a plurality of light sources are provided in each optical module, the communication capacity can be increased.

  In the third optical communication system of the present invention, in each of the plurality of optical modules, the wavelength of the light source can be increased as the distance from the optical fiber increases. Thereby, it can suppress that the light emitted from the light source is absorbed by the light source in the middle.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1. First Embodiment Hereinafter, an optical communication system according to an embodiment will be described.

1.1 Configuration of Optical Communication System FIG. 1 is a diagram schematically showing an optical communication system.

  The optical communication system 500 includes an optical fiber 510 and a plurality of light sources 20. The plurality of light sources 20 are provided along the optical axis A <b> 10 of the optical fiber 510. Specifically, the plurality of light sources 20 have the same optical axis and the same optical axis with the optical fiber 510. Light emitted from each of the plurality of light sources 20 travels on the optical axis A <b> 10 and is introduced into the optical fiber 510.

The wavelength λ of light emitted from the light source 20 is set to increase as the distance from the optical fiber 510 increases. That is, the wavelength of the light emitted from the light source 20 is set to be shorter as it goes to the light source in the direction in which the light is emitted. Specifically, assuming that the light from the light source 20 on the optical fiber 510 side is λ1 and the wavelengths of the light from the light source 20 are sequentially λ2... Λn as the distance from the optical fiber 510 increases, the wavelength λ of the light from the light source 20 is It sets so that Formula (1) may be satisfy | filled.
(Formula 1)
λ1 <λ2 <... <λn
When the wavelength λ of the light emitted from the light source 20 satisfies the above conditions, it is possible to suppress the light emitted from the light source 20 from being absorbed by the light source 20 in the middle.

  The light source 20 is not particularly limited as long as it can emit light, and examples thereof include a surface emitting semiconductor laser and a stripe laser.

1.2 Function and Effect Hereinafter, the function and effect of the optical communication system according to the embodiment will be described.

  (A) In the optical communication system 500 according to the present embodiment, the light source 20 is arranged along the optical axis A10 of the optical fiber 510. Therefore, it is not necessary to couple the light emitted from the plurality of light sources 20 to the optical fiber 510 with an optical multiplexer unlike the technique described in the background art (see FIG. 11). For this reason, according to this Embodiment, the light emitted from the several light source 20 can be combined with the optical fiber 510, without using an optical multiplexer.

  (B) The plurality of light sources 20 can be provided in the optical module 520. Since the plurality of light sources 20 are provided in the optical module 520, the optical axes of the plurality of light sources 20 and the optical fiber 510 can be aligned with one optical axis alignment between the optical module 520 and the optical fiber 510. . For this reason, the number of times of optical axis alignment can be reduced, manufacturing costs can be reduced, and productivity can be improved.

1.3 Modification In the optical communication system 600, a plurality of light source groups (for example, optical modules) 620 are provided in a plurality of rows, and light emitted from each of the plurality of light source groups 620 is coupled to the optical fiber 510 by the optical multiplexer 610. An aspect may be sufficient. In this case, although the optical multiplexer 610 is required, since each light source group 620 is provided with a plurality of light sources 20, the communication capacity can be increased as compared with the background art.

2. Second Embodiment Hereinafter, an example of an optical module according to an embodiment will be described. In the following description, the light source is a surface emitting semiconductor laser (hereinafter referred to as “surface emitting laser”).

2.1 Configuration of Optical Module FIG. 3 is a cross-sectional view schematically showing the optical module according to the embodiment.

  The optical module 100 includes a plurality of surface emitting lasers 20 (for example, first to third surface emitting lasers 20a, 20b, and 20c). Specifically, the optical module 100 can be configured by stacking a plurality of element forming substrates 10 on which the surface emitting lasers 20 are formed.

  The plurality of surface emitting lasers (first to third surface emitting lasers 20a, 20b, and 20c) have the same optical axis. The light emitted from the second surface emitting laser 20b passes through the first surface emitting laser 20a and is emitted to the outside. The light emitted from the third surface emitting laser 20c is transmitted through the first and second surface emitting lasers 20a and 20b and emitted to the outside.

  The oscillation wavelength of the surface emitting laser is set to be shorter as it goes to the surface emitting laser in the direction in which light is emitted. Thereby, it can suppress that the light radiate | emitted with a certain surface emitting laser is absorbed by another surface emitting laser on the way. The oscillation wavelengths of the plurality of surface emitting lasers (first to third surface emitting lasers 20a, 20b, and 20c) can be arbitrarily selected from a range of, for example, 650 to 1600 nm on condition that this condition is satisfied. More specifically, the first to third surface emitting lasers 20a, 20b, and 20c can take, for example, 850 nm, 980 nm, and 1300 nm, respectively.

  The oscillation wavelength λ2 of a certain surface emitting laser (for example, second surface emitting laser) 20b is, as shown in FIG. 10, the reflection band of the surface emitting laser (for example, first surface emitting laser) 20a adjacent in the light emitting direction. It is preferable to set so that it is not in R10. Thereby, it can suppress more reliably that the light emitted from the certain surface emitting laser 20b is reflected by the other surface emitting laser 20a.

  The element forming substrate 10 on which the surface emitting laser 20 is formed has, for example, the following configuration. FIG. 4 is a cross-sectional view schematically showing the element forming substrate 10 on which the surface emitting laser 20 is formed.

  The element formation substrate 10 is not particularly limited as long as it has a function of transmitting light emitted from the surface emitting laser 20 below the element formation substrate 10. For example, a semiconductor substrate (for example, a silicon substrate, a GaAs substrate, InP substrate, GaN substrate) can be selected as appropriate.

  The surface emitting laser 20 includes a resonator 60 provided on the element forming substrate 10. The resonator 60 includes a first DBR mirror 22, an active layer 24, and a second DBR mirror 26. Specifically, the resonator 60 is configured by sequentially laminating a first DBR mirror 22, an active layer 24, a second DBR mirror 26, and a contact layer 28 from the element formation substrate 10 side.

  The resonator 60 includes a columnar semiconductor deposited body (hereinafter referred to as “columnar portion”) 62. The columnar portion 62 includes at least the contact layer 28 and the second DBR mirror 26 (for example, the contact layer 28, the second DBR mirror 26, and the active layer 24).

  A surface emitting laser having an oscillation wavelength in the range of 780 to 850 nm can be made of, for example, an AlGaAs material. A surface emitting laser having an oscillation wavelength in the range of 980 to 1100 nm can be made of, for example, an InGaAs-based material. A surface emitting laser having an oscillation wavelength in the range of 1100 to 1300 nm can be made of, for example, a GaInNAs-based material. A surface emitting laser having an oscillation wavelength in the range of 1300 to 1600 nm can be made of an InGaAsP-based material. That is, when the wavelengths of the first to third surface emitting lasers 20a, 20b, and 20c are 850 nm, 980 nm, and 1300 nm, respectively, the first surface emitting laser 20a is made of an AlGaAs-based material, and the second surface emitting laser is used. The laser 20b can be made of an InGaAs material, and the third surface emitting laser 20c can be made of a GaInNAs material.

  The second DBR mirror 26 is made p-type by doping Zn or C, and the first DBR mirror 24 is made n-type by doping Se or Si. Therefore, the first DBR mirror 22, the active layer 24 not doped with impurities, and the second DBR mirror 26 form a pin diode.

  An insulating layer 52 is provided around the columnar portion 62. The insulating layer 52 is provided so that the upper surface of the contact layer 28 is exposed. On the insulating layer 52, an LD electrode 42 is provided. The LD electrode 42 is provided in contact with the end of the contact layer 28. The LD electrode 42 is configured, for example, by sequentially laminating a Cr film (for example, a film thickness of 10 nm), an AuZn film (for example, a film thickness of 200 nm), and an Au film (for example, a film thickness of 200 nm) from the insulating layer 52 side.

  The insulating layers 52 and 54 are provided with through holes 46a. A contact portion 46 is provided in the through hole 46a. The contact part 46 is electrically connected to the first DBR mirror 22. The contact part 46 and the LD electrode 42 are insulated by an insulating layer 54. The contact portion 46 can be provided at the end of the element formation substrate 10.

2.2 Mounting Example The element formation substrate 10 on which the plurality of surface emitting lasers 20 are formed is laminated so that the optical axes of the surface emitting lasers coincide with each other. An insulating layer 56 is provided between the element formation substrates 10 on which the surface emitting lasers 20 are formed. The insulating layer 56 can eliminate a short circuit between the adjacent surface emitting lasers 20.

  The element formation substrate 10 on which the surface emitting laser 20 is formed can be laminated stepwise. Specifically, the end portion of the element formation substrate 10 can be provided so as to protrude outward from the upper element formation substrate 10. Thereby, wiring (for example, bonding wire) 90 for drawing out each of the contact part 46 or the LD electrode 42 can be formed.

2.3 Manufacturing Process A device manufacturing process will be described with reference to FIGS.

  First, as shown in FIG. 5A, a semiconductor multilayer film 70 for the surface emitting laser 20 is formed on one surface of the element formation substrate 10 by epitaxial growth while modulating the composition. Specifically, a semiconductor film 72 for the first DBR mirror 22, a semiconductor film 74 for the active layer 24, a semiconductor film 76 for the second DBR mirror 26, and a semiconductor film 78 for the contact layer 28 are sequentially formed. .

The temperature at which the epitaxial growth is performed is preferably determined as appropriate depending on the type of the semiconductor substrate 10 or the type and thickness of the semiconductor multilayer film 70 to be formed. Further, the time required for performing the epitaxial growth is also appropriately determined in the same manner as the temperature. In addition, as a method for epitaxial growth, metal organic vapor phase epitaxy (MOVPE) method, MBE (Molecular Beam Epitaxy) method, or LPE method (Liquid Phase) is used.
Epitaxy) can be used.

  Next, a resist layer (not shown) having a predetermined pattern is formed on the semiconductor multilayer film 70. Next, as shown in FIG. 5B, the semiconductor multilayer film (at least the semiconductor films 74, 76, and 78) 70 is etched by dry etching using this resist layer as a mask, so that a columnar portion that is a columnar semiconductor deposit is formed. 62 is provided. Through the above steps, the resonator 60 including the columnar portion 62 is formed on the semiconductor substrate 10. In addition, after providing the columnar part 62, the side part of the active layer 24 can be selectively oxidized as needed.

  Next, as shown in FIG. 4, an insulating layer 52 is formed around the columnar portion. The insulating layer 52 is formed so that the upper surface of the contact layer 28 is exposed. The insulating layer 52 is formed as follows, for example. The insulating layer 52 can be formed by forming a resin precursor around the light emitting / receiving element 100 and irradiating the resin precursor with heat or light to solidify. An example of the resin precursor is a polyimide precursor. The temperature of the heat treatment usually applied when forming the insulating layer 52 varies depending on the type of the polyimide precursor, but is suitably 150 to 400 ° C, preferably 300 to 400 ° C.

  Next, a metal film (not shown) for the LD electrode is formed on the insulating layer 52 by vapor deposition. Next, the metal film for the LD electrode is patterned by lithography and etching to form the LD electrode 42 as shown in FIG.

  Next, an insulating layer (for example, a silicon oxide layer) 54 is formed by a known method on a region where the LD electrode 42 is not formed (contact layer 28 and insulating layer 52).

  Next, a through hole 46 a is formed at a predetermined position of the insulating layers 52 and 54. Next, the contact portion 46 is formed in the through hole 46a by a known method. As described above, the element forming substrate 10 on which the surface emitting laser 20 is formed can be formed.

  Next, as shown in FIG. 3, the element formation substrate 10 on which the surface emitting laser 20 is formed is laminated. The element forming substrate 10 is laminated so that the optical axes of the surface emitting lasers 20 coincide. Further, the element forming substrate 10 can be stacked through the insulating layer 56 so as not to be short-circuited between the surface emitting lasers 20.

  Next, wiring 90 for drawing out the contact portion 46 and the LD electrode 42 is formed by a known method.

2.4 Modification The number of the surface emitting lasers 20 is not limited to three, but may be a plurality of arbitrary numbers.

3. Third Embodiment 3.1 Second Optical Module Hereinafter, an example of an optical module according to a third embodiment will be described. In the following description, the light source is a surface emitting laser. FIG. 6 is a cross-sectional view schematically showing a second optical module according to the embodiment. FIG. 7 is a cross-sectional view schematically showing a light emitting element of the second optical module according to the embodiment.

  The second optical module 200 includes an element forming substrate 10 provided with a first surface emitting laser 20a on one side and a second surface emitting laser 20b on the other side. Specifically, the second optical module 200 is configured by mounting the element forming substrate 10 provided with the two light sources 20 a and 20 b on the mounting substrate 50.

  The first surface emitting laser 20a and the second surface emitting laser 20b have the same optical axis. The light emitted from the second surface emitting laser 20b passes through the first surface emitting laser 20a and is emitted to the outside.

  The oscillation wavelength of the second surface emitting laser 20b is set to be larger than the oscillation wavelength of the first surface emitting laser 20a. Thereby, it can suppress that the light radiate | emitted by the 2nd surface emitting laser 20b is absorbed by the 1st surface emitting laser 20a. Specifically, the oscillation wavelengths of the first and second surface emitting lasers 20a and 20b can be 850 nm and 980 nm, respectively.

  The oscillation wavelength λ2 of the second surface emitting laser 20b is preferably set so that it is not within the reflection band R10 of the first surface emitting laser 20a. Thereby, it can suppress more reliably that the light emitted from the 2nd surface emitting laser 20b is reflected by the 1st surface emitting laser 20a.

  Since the specific configurations of the first and second surface emitting lasers 20a and 20b and the element formation substrate 10 are the same as those in the second embodiment, detailed description thereof will be omitted, and different points will be described below.

  A contact electrode 146 may be formed on the surface of the first DBR mirror 22 of the second surface emitting laser 20b. For example, the contact electrode 146 is formed by sequentially laminating a Cr film (for example, a film thickness of 10 nm), an AuGe film (for example, a film thickness of 75 nm), a Ni film (for example, a film thickness of 15 nm), and an Au film (for example, a film thickness of 200 nm). Yes.

  The mounting substrate 50 includes a ground electrode 44 and a first LD electrode 142. The ground electrode 44 and the first LD electrode 142 are insulated by the insulating layer 154. For example, the ground electrode 44 is configured by sequentially laminating a Cr film (for example, a film thickness of 10 nm), an AuGe film (for example, a film thickness of 75 nm), a Ni film (for example, a film thickness of 15 nm), and an Au film (for example, a film thickness of 200 nm). Yes. The first LD electrode 142 can be made of, for example, an Au film.

  The first LD electrode 142 is electrically connected to the contact layer 28 of the second surface emitting laser 20b. The contact electrode 146 is electrically connected to the ground electrode 44 through the solder 156. Thereby, the first DBR 22 of the second surface emitting laser 20b and the ground electrode 44 are electrically connected via the contact electrode 46 and the solder 156. Further, the first DBR mirror 22 and the ground electrode 44 of the first surface emitting laser 20a are electrically connected via the n-type semiconductor substrate 10, the first DBR mirror 22 of the second surface emitting laser 20b, the contact electrode 146, and the solder 156. Will be connected to.

  An insulating layer 52 is provided so as to cover the periphery of the element formation substrate 10 on which the surface emitting lasers 20a and 20b are formed. The insulating layer 52 is formed so that the upper surface of the contact layer 28 of the first surface emitting laser 20a is exposed. On the insulating layer 52, a second LD electrode 42 for the second surface emitting laser 20b is provided. The second LD electrode 42 is configured, for example, by sequentially laminating a Cr film (for example, a film thickness of 10 nm), an AuZn film (for example, a film thickness of 200 nm), and an Au film (for example, a film thickness of 200 nm) from the insulating layer 52 side.

3.2 Device Manufacturing Process A device manufacturing process according to the present embodiment will be described with reference to FIGS.

  First, as shown in FIG. 8A, a first semiconductor multilayer film 170 is formed on one surface of an n-type semiconductor substrate (for example, an n-type GaAs substrate) 10. As this formation method, the formation method of the first semiconductor multilayer film 70 of the second embodiment can be applied.

  Next, the second semiconductor multilayer film 180 is formed on the other surface of the n-type semiconductor substrate 10. As this formation method, the formation method of the first semiconductor multilayer film 70 of the second embodiment can be applied.

  Next, a resist layer (not shown) having a predetermined pattern is formed on the first semiconductor multilayer film 70. Next, as shown in FIG. 8B, the first semiconductor multilayer film 170 is etched and patterned by a dry etching method using this resist layer as a mask to provide a columnar portion 62 for the first surface emitting laser 20a. . Through the above steps, the resonator 60 including the columnar portion 62 for the first surface emitting laser 20a is formed on the semiconductor substrate 10.

  Next, similarly to the first semiconductor multilayer film 170, the second semiconductor multilayer film 180 is etched and patterned to form the resonator 60 including the columnar portion 62 for the second surface emitting laser 20b. The patterning of the second semiconductor multilayer film 180 is performed so that the optical axes of the first surface emitting laser 20a and the second surface emitting laser 20b coincide. The back surface alignment technique can be applied to pattern the second semiconductor multilayer film 180 so that the optical axes of the first surface emitting laser 20a and the second surface emitting laser 20b coincide.

  In addition, after providing the columnar part 62, the side part of the active layer 24 can be selectively oxidized as needed.

  Next, a metal film (not shown) for the contact electrode 146 is formed on the surface on the second surface emitting laser 20b side by vapor deposition. Next, the metal film is patterned using lithography and etching techniques to form a contact electrode 146 on the first DBR mirror 22 of the second surface emitting laser 20b as shown in FIG.

  Next, as shown in FIG. 6, the element formation substrate 10 on which the surface emitting lasers 20 a and 20 b are formed is mounted on the mounting substrate 50. Specifically, the ground electrode 44 and the contact electrode 146 of the mounting substrate 50 are electrically connected by, for example, solder 156. Further, the contact layer 28 of the second surface emitting laser 20b and the first LD electrode 142 are electrically connected.

  Next, an insulating layer 52 is formed around the element formation substrate 10 on which the surface emitting lasers 20a and 20b are formed. The insulating layer 52 is formed so that the upper surface of the contact layer 28 of the first surface emitting laser 20a is exposed. The insulating layer 52 can be formed in the same manner as the insulating layer in the second embodiment.

  Next, a metal film (not shown) for the second LD electrode 42 is formed on the insulating layer 52 by vapor deposition. Next, the second LD electrode 42 is formed by patterning a metal film for the second LD electrode 42 by lithography and etching. A device can be formed as described above.

3.3 Modifications As shown in FIG. 9, a plurality of element forming substrates 10 including the surface emitting laser as described above may be stacked. Hereinafter, a mode in which two element forming substrates 10 including the surface emitting laser as described above are stacked will be described.

  Insulating layers 52 a and 52 b are provided around each of the two element formation substrates 10. A ground electrode 144, a second LD electrode 122, and a third LD electrode 124 can be provided between the two element formation substrates 10. The ground electrode 144 can be electrically connected to the second and third surface emitting lasers 20 b and 20 c via the solder 156. The second LD electrode 122 functions as an electrode that supplies a potential to the third surface emitting laser 20b, and the third LD electrode 124 functions as an electrode that supplies a potential to the second surface emitting laser 20b. The second LD electrode 122, the third LD electrode 124, and the ground electrode 144 are insulated from each other by the insulating layer 154.

  A first LD electrode 120 is provided on the mounting substrate 150. The first LD electrode 120 functions as an electrode that supplies a potential to the fourth surface emitting laser 20d. The fourth LD electrode 126 functions as an electrode that supplies a potential to the first surface emitting laser 20a.

  In addition, the mounting method of the element formation board | substrate 10 to the mounting board | substrate 50 is not limited to said mounting method, The other well-known mounting method is applicable.

4). Modified Example The above-described embodiment can be modified as follows, for example.

  The aspect which mounted the 2nd surface emitting laser element on the back surface of the board | substrate with which the 1st surface emitting laser was provided may be sufficient. In this case, the optical axes of the first surface emitting laser and the second surface emitting laser element can be aligned by the back surface alignment technique.

  Alternatively, the first surface-emitting laser element can be mounted on one surface of one substrate and the second surface-emitting laser element can be mounted on the other surface.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

It is a figure which shows typically the optical communication system which concerns on embodiment. It is a figure which shows typically the optical communication system which concerns on a modification. It is sectional drawing which shows the optical module which concerns on 2nd Embodiment. It is sectional drawing which shows typically the element formation board | substrate 10 with which the surface emitting laser 20 was formed. It is sectional drawing which shows typically the manufacturing process of the optical module which concerns on 2nd Embodiment. It is sectional drawing which shows the optical module which concerns on 3rd Embodiment. It is sectional drawing which shows typically the element formation board | substrate with which two surface emitting lasers were formed. It is sectional drawing which shows typically the manufacturing process of the optical module which concerns on 3rd Embodiment. It is sectional drawing which shows the optical module which concerns on a modification. It is a figure which shows the relationship between the reflectance of a surface emitting laser, and a wavelength. It is a figure which shows typically the optical communication system which concerns on the past.

Explanation of symbols

10 element forming substrate, 20 light source, 20a first surface emitting laser, 20b second surface emitting laser, 20c third surface emitting laser, 20d fourth surface emitting laser, 22 first DBR mirror, 24 active layer, 26 second DBR mirror, 42 LD electrode, second LD electrode, 44 ground electrode, 46 contact portion, 50 mounting substrate, 52, 54, 56 insulating layer, 52a, 52b insulating layer, 60 resonator, 62 columnar portion, 70 semiconductor multilayer film, 90 wiring, 100, 200 optical module, 120 first LD electrode, 122 second LD electrode, 124 third LD electrode, 126 fourth LD electrode, 142 first LD electrode, 144 ground electrode, 146 contact electrode, 150 mounting substrate, 154 insulating layer, 156 solder, 170 first semiconductor multilayer film, 180 second semiconductor multilayer film, 500 , 600 optical communication system, 510 optical fiber, 610 optical multiplexer, 620 optical module, R10 reflection band, λ oscillation wavelength

Claims (5)

A first surface emitting semiconductor laser;
A first substrate provided under the first surface emitting semiconductor laser;
A second surface emitting semiconductor laser provided under the first substrate;
A second substrate provided under the second surface emitting semiconductor laser;
Including
The first surface emitting semiconductor laser and the second surface emitting semiconductor laser are:
A first DBR mirror;
An active layer formed on the first DBR mirror;
A second DBR mirror formed on the active layer;
A contact layer formed on the second DBR mirror;
A contact portion electrically connected to the first DBR mirror;
An electrode electrically connected to the second DBR mirror;
Have
The contact layer, the second DBR mirror, and the active layer constitute a columnar portion,
A first insulating layer is provided around the columnar portion,
The first insulating layer is provided with a through hole that reaches the first DBR mirror,
The contact portion is provided in the through hole,
The upper surface of the first insulating layer and the upper surface of the contact layer are flush with each other,
The electrode is provided on an end of the contact layer and on the first insulating layer;
The end of the second substrate protrudes outward from the end of the first substrate,
A part of the contact part and the electrode of the second surface emitting semiconductor laser is formed outside an end part of the first substrate;
A second insulating layer is provided on the first insulating layer and between the contact portion and the electrode;
The optical axis of the first surface emitting semiconductor laser and the optical axis of the second surface emitting semiconductor laser are coincident,
The wavelength of the light emitted from the second surface emitting semiconductor laser is longer than the wavelength of the light emitted from the first surface emitting semiconductor laser.
Outgoing wavelength of the second surface-emitting type semiconductor laser, Ri anywhere besides the reflection band of the first surface-emitting type semiconductor laser,
The oscillation wavelengths of the first surface emitting laser and the second surface emitting laser are 780 nm to 1300 nm,
The optical module , wherein the first substrate is a silicon substrate . The optical module according to claim 1,
An optical module further comprising an insulating layer formed between the first surface emitting semiconductor laser and the second surface emitting semiconductor laser. The optical module according to claim 1 or 2,
The first substrate is an optical module having a function of transmitting light emitted from the second surface emitting semiconductor laser. Optical fiber,
Including the optical module according to claim 1,
An optical communication system in which the optical fiber and the optical module have the same optical axis. A plurality of optical modules according to any one of claims 1 to 3;
Including optical fiber,
An optical communication system, wherein a plurality of lights emitted from each of the plurality of optical modules are coupled to the optical fiber by an optical multiplexer.

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