JP2011014580A - Light receiving and emitting device, and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light receiving and emitting device for monolithically integrating a light emitting element and a light receiving element.SOLUTION: In the light receiving and emitting device 100, a light emitting region 160 and a light receiving region 190 are partitioned by a first isolation trench 180. The light emitting region 160 has a first gain region 162 and a second gain region 164. A distance between the first gain region 162 and the second gain region 164 becomes smaller as a second side face 107-side of a light receiving and emitting layer 106, which is parallel to a first side face 105, approaches from a first side face 105-side of the light receiving and emitting layer 106. The first gain region 162 and the second gain region 164 are arranged by inclining them with respect to a perpendicular line P of the first side face 105 if viewed in terms of a plane. The light receiving region 190 is positioned between the first gain region 162 and the second gain region 164. Light leaked from the first gain region 162 and the second gain region 164 reaches the light receiving region 190 and is received as the distance between the first gain region 162 and the second gain region 164 becomes smaller.

Description

  The present invention relates to a light emitting / receiving device and a projector.

  In a semiconductor light emitting device used in optical communication or the like, in general, a part of emitted light is taken out by arranging a semi-transmissive mirror or a diffraction element outside the apparatus, and the light is detected by a light receiving element. The amount of light is adjusted.

  For example, Patent Document 1 proposes an optical pickup device having a monitoring photodiode for branching light from a laser diode with a spectroscopic prism or the like and detecting the branched light.

JP-A-10-3691

  However, in the method disclosed in Patent Document 1, since the light emitting element and the light receiving element are individually provided, an optical element such as a spectral prism is required separately, which increases the number of components and is difficult to reduce in size. Is considered. In addition, in order to use in a display device, it is necessary to individually detect the light amounts of a plurality of laser diodes, but it may be difficult to provide a light receiving element individually.

  One of the objects according to some aspects of the present invention is to provide a light receiving and emitting device capable of monolithically integrating a light emitting element and a light receiving element. Another object of some aspects of the present invention is to provide a projector having the light emitting and receiving device.

The light emitting / receiving device according to the present invention includes:
A first cladding layer;
A light emitting / receiving layer formed above the first cladding layer and having a light emitting region and a light receiving region;
A second cladding layer formed above the light emitting / receiving layer;
Including
The light emitting region and the light receiving region are partitioned by a first separation groove,
The light emitting region has a first gain region and a second gain region,
The distance between the first gain region and the second gain region decreases from the first side surface side of the light emitting / receiving layer toward the second side surface side of the light emitting / receiving layer parallel to the first side surface. ,
The first gain region and the second gain region are provided to be inclined with respect to a normal to the first side surface in a plan view,
The light receiving region is located between the first gain region and the second gain region,
As the distance between the first gain region and the second gain region decreases, the light leaking from the first gain region and the second gain region reaches the light receiving region and is received.

  According to such a light emitting / receiving device, light leaking from the first gain region and the second gain region can be absorbed and received by the light receiving region. Therefore, the light emitting element and the light receiving element can be monolithically integrated.

  In the description of the present invention, the word “upper” is, for example, “forms another specific thing (hereinafter referred to as“ B ”)“ above ”a specific thing (hereinafter referred to as“ A ”)”. Etc. In the description according to the present invention, in the case of this example, the case where B is directly formed on A and the case where B is formed on A via another are included. The word “upward” is used.

In the light emitting / receiving device according to the present invention,
A distance from the light receiving region to the second side surface may be smaller than a distance from the light receiving region to the first side surface.

  According to such a light receiving and emitting device, the light receiving region can be arranged in a place where the amount of light leakage from the first gain region and the second gain termination region is large. Therefore, the light detection capability can be improved.

In the light emitting / receiving device according to the present invention,
The first gain region and the second gain region are provided from the first side surface to the second side surface,
In the wavelength band of light generated in the first gain region and the second gain region, the reflectance of the first side surface is smaller than the reflectance of the second side surface,
At least a part of the end surface of the first gain region on the second side surface side may overlap with at least a part of the end surface of the second gain region on the second side surface side.

  According to such a light emitting / receiving device, a part of the light generated in the first gain region is reflected on the overlapping surface and can travel while receiving the gain even in the second gain region. The same applies to part of the light generated in the second gain region. Therefore, according to such a light receiving and emitting device, since the amplification distance of the light intensity becomes longer as compared with, for example, a case where reflection is not actively performed on the overlapping surface, a high light output can be obtained.

In the light emitting / receiving device according to the present invention,
The first gain region and the second gain region are provided from the first side surface to the second side surface,
The end surface of the first gain region on the second side surface side and the end surface of the second gain region on the second side surface side may be separated from each other.

  According to such a light emitting / receiving device, light emitted from the two side surfaces (the first side surface and the second side surface) can be used.

In the light emitting / receiving device according to the present invention,
The first gain region is provided from the first side surface to the second side surface,
The second gain region is provided from the second side surface to the first side surface and the third side surface of the light receiving and emitting layer orthogonal to the second side surface,
The light emitting region further has a third gain region,
The third gain region is provided from the first side surface to the third side surface,
In the wavelength band of light generated in the first gain region, the second gain region, and the third gain region, the reflectance of the first side surface is smaller than the reflectance of the second side surface and the third side surface,
At least a part of the end surface of the first gain region on the second side surface side overlaps at least a part of the end surface of the second gain region on the second side surface side, and
At least a part of the end surface on the third side surface side of the second gain region overlaps with at least a part of the end surface on the third side surface side of the third gain region,
The light emitted from the end surface on the first side surface side of the first gain region and the light emitted from the end surface on the first side surface side of the third gain region proceed in the same direction or in a converging direction. be able to.

  According to such a light receiving and emitting device, for example, the optical system (an optical system into which the emitted light is incident) can be reduced in size as compared with a case where the two emitted lights travel in a diverging direction.

In the light emitting / receiving device according to the present invention,
The first gain region and the second gain region form a gain region pair,
A plurality of the gain region pairs are arranged,
A second separation groove is formed between the adjacent gain region pairs,
The plurality of gain region pairs may be electrically separated from each other by the second separation groove.

  According to such a light emitting / receiving device, it is possible to increase the output of light emission. Further, since the plurality of gain region pairs are electrically separated from each other by the second separation groove, the light output of each of the plurality of gain region pairs can be monitored. That is, it is possible to individually detect the amount of light for each of the plurality of gain region pairs.

In the light emitting / receiving device according to the present invention,
A contact layer formed above the second cladding layer;
A first electrode electrically connected to the first cladding layer;
A second electrode in contact with the contact layer located above the first gain region and the second gain region;
A third electrode in contact with the first contact layer located above the light receiving region;
Further including
The planar shapes of the first gain region and the second gain region are the same as the planar shape of the contact surface between the second electrode and the contact layer,
The planar shape of the light receiving region may be the same as the planar shape of the contact surface between the third electrode and the contact layer.

  According to such a light emitting / receiving device, the contact resistance of the second electrode and the third electrode can be reduced by the contact layer.

The projector according to the present invention is
A light emitting and receiving device according to the present invention;
A light modulation device that modulates light emitted from the light emitting and receiving device according to image information;
A projection device for projecting an image formed by the light modulation element;
including.

  According to such a projector, since the light emitting / receiving device capable of monolithically integrating the light emitting element and the light receiving element is used, the number of parts is reduced and the manufacturing is performed as compared with the case where the light receiving element is separately installed. Cost can be reduced.

The top view which shows typically the light emitting / receiving apparatus which concerns on this embodiment. 1 is a cross-sectional view schematically showing a light emitting / receiving device according to an embodiment. The figure which looked at the light emitting / receiving layer of the light emitting / receiving device according to this embodiment in a plan view from the first side surface side. Sectional drawing which shows typically the manufacturing process of the light emitting and receiving apparatus which concerns on this embodiment. Sectional drawing which shows typically the manufacturing process of the light emitting and receiving apparatus which concerns on this embodiment. The top view which shows typically the light receiving and emitting apparatus which concerns on the 1st modification of this embodiment. Sectional drawing which shows typically the light receiving and emitting apparatus which concerns on the 1st modification of this embodiment. The top view which shows typically the light receiving and emitting apparatus which concerns on the 2nd modification of this embodiment. The top view which shows typically the light emitting and receiving apparatus which concerns on the 3rd modification of this embodiment. Sectional drawing which shows typically the light receiving and emitting apparatus which concerns on the 4th modification of this embodiment. 1 is a diagram schematically showing a projector according to an embodiment.

1. First, the light emitting / receiving device 100 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing the light emitting / receiving device 100. 2 is a cross-sectional view taken along line II-II in FIG. In FIG. 1, the second electrode 113 is not shown for convenience. Here, a case where the light emitting / receiving device 100 is an InGaAlP-based (red) semiconductor light emitting device will be described.

  Hereinafter, the configuration of the light receiving / emitting device 100, the light emission operation principle, and the light reception operation principle will be described in this order.

(1) Configuration As shown in FIGS. 1 and 2, the light emitting / receiving device 100 includes a first cladding layer 104, a light emitting / receiving layer 106, and a second cladding layer 108. The light emitting / receiving device 100 can further include a substrate 102, a contact layer 110, a first electrode 112, a second electrode 113, a third electrode 114, and an insulating part 116.

  As the substrate 102, for example, a first conductivity type (for example, n-type) GaAs substrate or the like can be used.

  The first cladding layer 104 is formed on the substrate 102. As the first cladding layer 104, for example, an n-type AlGaP layer can be used. Although not shown, a buffer layer may be formed between the first substrate 102 and the first cladding layer 104. As the buffer layer, for example, an n-type GaAs layer, an InGaP layer, or the like can be used. The buffer layer can improve the crystallinity of the layer formed thereabove.

  The light receiving / emitting layer 106 is formed on the first cladding layer 104. The light emitting / receiving layer 106 has, for example, a multiple quantum well (MQW) structure in which three quantum well structures each composed of an InGaP well layer and an InGaAlP barrier layer are stacked.

  The light receiving / emitting layer 106 is partitioned into a light emitting region 160 and a light receiving region 190 by the first separation groove 180.

  The light emitting region 160 has a first gain region 162 and a second gain region 164. The first gain region 162 and the second gain region 164 can constitute a pair of gain regions (gain region pair). The gain regions 162 and 164 can generate light, and this light can receive gain within the gain regions 162 and 164. The shape of the light receiving / emitting layer 106 is, for example, a rectangular parallelepiped (including a cube). The light emitting / receiving layer 106 has a first side surface 105 and a second side surface 107 as shown in FIGS. 1 and 2. The first side surface 105 and the second side surface 107 face each other and are parallel to each other.

In the wavelength band of light generated in the gain regions 162 and 164, the reflectance of the first side surface 105 is smaller than the reflectance of the second side surface 107. For example, as shown in FIG. 1, the second side surface 107 can obtain a high reflectance by covering the second side surface 107 with the reflecting portion 130. The reflection unit 130 is, for example, a dielectric multilayer mirror. More specifically, a dielectric multilayer mirror or the like in which 10 pairs are laminated in the order of the SiO ₂ layer and the Ta ₂ O ₅ layer from the second side surface 107 side can be used as the reflecting portion 130. The reflectance of the second side surface 107 is desirably 100% or close thereto. On the other hand, the reflectance of the first side surface 105 is desirably 0% or close thereto. For example, a low reflectance can be obtained by covering the first side surface 105 with an antireflection portion (not shown).

  Each of the gain regions 162 and 164 is provided from the first side surface 105 to the second side surface 107 in a direction inclined with respect to the normal line P of the first side surface 105 as viewed in plan as shown in FIG. Yes. Thereby, the laser oscillation of the light generated in the gain regions 162 and 164 can be suppressed or prevented. The first gain region 162 and the second gain region 164 are provided in different directions. For example, the first gain region 162 is inclined toward one side with respect to the perpendicular P, and is provided in one direction (also referred to as a first direction) having an inclination of an angle θ. In addition, the second gain region 164 is inclined to the other side (opposite side of the one side) with respect to the perpendicular P, for example, in another direction (also referred to as the second direction) having an inclination of the angle θ. It is provided. The distance between the first gain region 162 and the second gain region 164 decreases as the distance from the first side surface 105 approaches the second side surface 107.

  The first gain region 162 has a first end surface 170 provided on the first side surface 105 and a second end surface 172 provided on the second side surface 107. The second gain region 164 has a third end surface 174 provided on the first side surface 105 and a fourth end surface 176 provided on the second side surface 107. In the illustrated example, the second end surface 172 and the fourth end surface 176 completely overlap each other on the overlapping surface 178. The planar shape of the first gain region 162 and the planar shape of the second gain region 164 are line symmetric with respect to the normal line P in the second end surface 172 or the fourth end surface 176, for example. The planar shape of the first gain region 162 and the planar shape of the second gain region 164 are line symmetric with respect to the perpendicular bisector P of the overlapping surface 178, for example. The planar shape of each of the first gain region 162 and the second gain region 164 is, for example, a parallelogram.

  Here, FIG. 3 is a plan view of the light emitting / receiving layer 106 viewed from the first side surface 105 side. As shown in FIG. 3, the first end surface 170 and the second end surface 172 of the first gain region 162 do not overlap. Similarly, the third end surface 174 and the fourth end surface 176 of the second gain region 164 do not overlap. Thereby, the light generated in the first gain region 162 is between the first end surface 170 and the second end surface 172, and the light generated in the second gain region 164 is between the third end surface 174 and the fourth end surface 176. Direct multiple reflections can be avoided. As a result, since a direct resonator cannot be configured, laser oscillation of light generated in the gain regions 162 and 164 can be more reliably suppressed or prevented. Therefore, the light emitting / receiving device 100 can emit light that is not laser light. In this case, as shown in FIG. 3, for example, in the first gain region 162, the displacement width x between the first end surface 170 and the second end surface 172 may be a positive value.

  As shown in FIGS. 1 and 2, the light receiving region 190 is provided between the first gain region 162 and the second gain region 164. In the example shown in FIG. 1, the distance from the light receiving region 190 to the second side surface 107 is smaller than the distance from the light receiving region 190 to the first side surface 105. The planar shape of the light receiving region 190 is not particularly limited, but is a triangle in the illustrated example. In this case, it is desirable that the vertex A of the light receiving region 190 is as close as possible to the intersection B between the first gain region 162 and the second gain region 164. The light receiving region 190 can absorb light.

  The first separation groove 180 is formed around the light receiving region 190 in plan view as shown in FIG. In the illustrated example, the inner periphery 180 a of the first separation groove 180 is in contact with the light receiving region 190. The outer periphery 180b of the first separation groove 180 is in contact with the first gain region 162 and the second gain region 164. As shown in FIG. 2, the bottom surface of the first separation groove 180 is positioned below the lower surface of the light emitting / receiving layer 106. The light emitting region 160 and the light receiving region 190 are electrically separated by the first separation groove 180.

  As shown in FIG. 2, the second cladding layer 108 is formed on the light receiving / emitting layer 106. As the second cladding layer 108, for example, a second conductivity type (for example, p-type) AlGaP layer or the like can be used.

  The contact layer 110 is formed on the second cladding layer 108. As the contact layer 110, a layer in ohmic contact with the second electrode 113 and the third electrode 114 can be used. As the contact layer 110, for example, a p-type GaAs layer can be used. The contact layer 110 can reduce the contact resistance between the second electrode 113 and the third electrode 114.

The insulating part 116 is formed on the contact layer 110. The insulating part 116 can be in contact with the contact layer 110 located above the light emitting region 160 where the gain regions 162 and 164 are not formed. As the insulating part 116, for example, a SiN layer, a SiO ₂ layer, a polyimide layer, or the like can be used.

  The first electrode 112 is formed on the entire lower surface of the substrate 102. The first electrode 112 can be in contact with a layer that is in ohmic contact with the first electrode 112 (the substrate 102 in the illustrated example). The first electrode 112 is electrically connected to the first cladding layer 104 via the substrate 102. The first electrode 112 is one electrode for generating light in the gain regions 162 and 164, and is also one electrode for receiving light reaching the light receiving region 190. That is, the first electrode 112 can have a function as a light emitting electrode and a function as a light receiving electrode. As the first electrode 112, for example, a layer in which a Cr layer, an AuGe layer, a Ni layer, and an Au layer are stacked in this order from the substrate 102 side can be used. Note that a second contact layer (not shown) is provided between the first cladding layer 104 and the substrate 102, the second contact layer is exposed by dry etching or the like, and the first electrode 112 is placed on the second contact layer. It can also be provided. Thereby, a single-sided electrode structure can be obtained. This form is particularly effective when the substrate 102 is insulative.

  The second electrode 113 is formed on the contact layer 110. The second electrode 113 can be in contact with the contact layer 110 located above the gain regions 162 and 164. The contact surface between the second electrode 113 and the contact layer 110 has a planar shape similar to that of the gain regions 162 and 164. That is, for example, the current path between the electrodes 112 and 113 is determined by the planar shape of the contact surface between the second electrode 113 and the contact layer 110, and as a result, the planar shape of the gain regions 162 and 164 is determined. The second electrode 113 is electrically connected to the second cladding layer 108 via the contact layer 110. The second electrode 113 is the other electrode (light emitting electrode) for generating light in the gain regions 162 and 164. As the second electrode 113, for example, a layer in which a Cr layer, an AuZn layer, and an Au layer are stacked in this order from the contact layer 110 side can be used. Note that the second electrode 113 may be further formed on the insulating portion 116 as shown in FIG.

  The third electrode 114 is formed on the contact layer 110. The third electrode 114 can be in contact with the contact layer 110 located above the light receiving region 190. The contact surface between the third electrode 114 and the contact layer 110 has a planar shape similar to that of the light receiving region 190. The third electrode 114 is electrically connected to the second cladding layer 108 via the contact layer 110. The third electrode 114 is the other electrode (light receiving electrode) for receiving the light reaching the light receiving region 190. As the third electrode 114, for example, the same material as that of the second electrode 113 can be used.

(2) Principle of operation of light emission For example, the p-type second cladding layer 108, the light emitting / receiving layer 106 not doped with impurities, and the n-type first cladding layer 104 constitute a pin diode. Each of the first cladding layer 104 and the second cladding layer 108 is a layer having a larger forbidden band width and a smaller refractive index than the light emitting / receiving layer 106. The light receiving / emitting layer 106 (gain regions 162 and 164) has a function of amplifying light. The first cladding layer 104 and the second cladding layer 108 have a function of confining injected carriers (electrons and holes) and light with the light emitting / receiving layer 106 interposed therebetween.

  In the light emitting / receiving device 100, when a forward bias voltage of a pin diode is applied between the first electrode 112 and the second electrode 113, electrons and holes are recombined in the gain regions 162 and 164 of the light emitting / receiving layer 106. Occur. This recombination causes light emission. Starting from the generated light, stimulated emission occurs in a chain, and the light intensity is amplified in the gain regions 162 and 164. For example, as shown in FIG. 1, a part of the light 10 generated in the first gain region 162 is amplified in the first gain region 162, then reflected on the overlapping surface 178, and the second gain region 164 in the second gain region 164. Although it is emitted as the emitted light 20 from the three end faces 174, the light intensity is also amplified in the second gain region 164 after reflection. Similarly, a part of the light generated in the second gain region 164 is amplified in the second gain region 164 and then reflected by the overlapping surface 178 and emitted from the first end surface 170 of the first gain region 162. However, the light intensity is also amplified in the first gain region 162 after reflection. Note that some of the light generated in the first gain region 162 is directly emitted from the first end face 170 as the emitted light 20. Similarly, some of the light generated in the second gain region 164 is emitted directly from the third end face 174 as the emitted light 20. These lights are similarly amplified in the gain regions 162 and 164.

  As described above, the light emitting / receiving device 100 can constitute a pin diode for light emission. That is, the light emitting / receiving device 100 includes the first cladding layer 104, the light emitting region 160 (gain regions 162 and 164) of the light receiving / emitting layer 106, the second cladding layer 108, the first electrode 112, and the second electrode 113. Can be configured.

(3) Operating Principle of Light Reception The distance between the first gain region 162 and the second gain region 164 decreases as the distance from the first side surface 105 side approaches the second side surface 107 side. Then, due to the evanescent coupling, a part of the light traveling in the first gain region 162 from the first end face 170 side to the second end face 172 side does not pass through the overlapping face 178, and the second gain. Begin moving to region 164. That is, the light traveling in the first gain region 162 toward the second end surface 172 feels the second gain region 164 which is a high refractive region, and a part thereof moves to the second gain region 164 side. Can be bent. The light leaking from the first gain region 162 reaches the light receiving region 190 located between the gain regions 162 and 164. Similarly, the light traveling in the second gain region 164 from the third end surface 174 side toward the fourth end surface 176 side feels the first gain region 162, and a part thereof is on the first gain region 162 side. To the light receiving area 190.

  The light that reaches the light receiving region 190 generates electrons and holes in the light receiving region 190. When a reverse bias voltage of a pin diode is applied between the first electrode 112 and the third electrode 114, the electron-hole pairs generated in the light receiving region 190 are accelerated and can be taken out as a current.

  As described above, the light emitting / receiving device 100 can constitute a pin photodiode for receiving light. That is, in the light emitting / receiving device 100, the first cladding layer 104, the light receiving region 190 of the light receiving / emitting layer 106, the second cladding layer 108, the first electrode 112, and the third electrode 114 can constitute a light receiving element.

  Although the case of the InGaAlP system has been described as an example of the light emitting / receiving device 100 according to the present embodiment, the light receiving / emitting device 100 can use any material system capable of forming a light emission gain region. As the semiconductor material, for example, an AlGaN-based, InGaN-based, GaAs-based, AlGaAs-based, InGaAs-based, InGaAsP-based, ZnCdSe-based semiconductor material can be used.

  The light emitting / receiving device 100 according to the present embodiment can be applied to a light source such as a projector, a display, a lighting device, and a measurement device.

  The light emitting / receiving device 100 according to the present embodiment has the following features, for example.

  According to the light emitting / receiving device 100, the light receiving / emitting layer 106 can include the light emitting region 160 constituting the gain regions 162 and 164 and the light receiving region 190. The light leaking from the gain regions 162 and 164 reaches the light receiving region 190 and can be received. That is, in the light emitting / receiving device 100, the light emitting element (light emitting area) and the light receiving element (light receiving area) can be monolithically integrated. Thereby, for example, compared with the case where a light receiving element is separately installed, the number of parts and the manufacturing cost can be reduced.

  According to the light receiving and emitting device 100, the light output from the gain regions 162 and 164 can be monitored by receiving the light leaking from the gain regions 162 and 164. Therefore, the voltage value applied to the first electrode 112 and the second electrode 113 can be adjusted based on the monitored light output. Thereby, in the light emitting / receiving device 100, the luminance unevenness can be reduced and the brightness can be automatically adjusted. The control for feeding back the optical output of the gain regions 162 and 164 to the applied voltage value can be performed using, for example, an external electronic circuit (not shown).

  According to the light receiving and emitting device 100, the distance from the light receiving region 190 to the second side surface 107 can be smaller than the distance from the light receiving region 190 to the first side surface 105. That is, the light receiving region 190 can be brought close to the intersection B between the first gain region 162 and the second gain region 164. The closer to the intersection B, the easier the evanescent coupling occurs. Therefore, the light receiving region 190 can be arranged at a place where the amount of light leakage from the gain regions 162 and 164 is large. Therefore, in the light emitting / receiving device 100, the light detection capability can be improved. Further, for example, the detection capability can be adjusted by changing the angle of the gain regions 162 and 164 with respect to the perpendicular P.

  According to the light emitting / receiving device 100, a part of the light 10 generated in the first gain region 162 is reflected by the overlapping surface 178 and can travel in the second gain region 164 while receiving gain. The same applies to part of the light generated in the second gain region 164. Therefore, according to the light emitting / receiving device 100, for example, compared with the case where the light is not actively reflected on the overlapping surface 178, the amplification distance of the light intensity becomes longer, and thus a high light output can be obtained.

2. Next, a method for manufacturing the light emitting / receiving device 100 according to the present embodiment will be described with reference to the drawings. 4 and 5 are cross-sectional views schematically showing the manufacturing process of the light emitting and receiving device 100. FIG.

  As shown in FIG. 4, the first cladding layer 104, the light emitting / receiving layer 106, the second cladding layer 108, and the contact layer 110 are epitaxially grown on the substrate 102 in this order. As a method for epitaxial growth, for example, MOCVD (Metal Organic Chemical Vapor Deposition) method, MBE (Molecular Beam Epitaxy) method or the like can be used.

  As shown in FIG. 5, the insulating part 116 is formed on the contact layer 110. Specifically, an insulating layer (not shown) is formed on the entire surface of the contact layer 110 by a CVD (Chemical Vapor Deposition) method, a coating method, or the like, and the insulating layer 116 is formed by patterning the insulating layer. be able to. The contact layer 110 is exposed by the patterning. The patterning is performed using, for example, a photolithography technique and an etching technique. Next, an electrode layer 115 to be the electrodes 113 and 114 is formed on the contact layer 110 and the insulating portion 116. Next, the first electrode 112 is formed under the lower surface of the substrate 102. The electrode layer 115 and the first electrode 112 are formed by, for example, a vacuum evaporation method. Note that the order of forming the electrode layer 115 and the first electrode 112 is not particularly limited.

  As shown in FIG. 2, the electrode layer 115, the contact layer 110, the second cladding layer 108, the light emitting / receiving layer 106 and the first cladding layer 104 are etched to form a first separation groove 180. The light emitting region 160 and the light receiving region 190 can be partitioned by the first separation groove 180. Further, the second electrode 113 and the third electrode 114 are partitioned by the first separation groove 180.

  The light emitting / receiving device 100 can be manufactured through the above steps.

  According to the method for manufacturing the light emitting / receiving device 100, the light emitting / receiving device 100 capable of monolithically integrating the light emitting elements and the light receiving elements can be formed.

3. Next, a light emitting / receiving device 200, 300, 400, 500 according to a modification of the present embodiment will be described with reference to the drawings. Hereinafter, in the light receiving and emitting devices 200, 300, 400, and 500 according to the modified example of the present embodiment, members having the same functions as the constituent members of the light receiving and emitting device 100 according to the present embodiment are denoted by the same reference numerals. Detailed description thereof is omitted.

(1) Light receiving and emitting device according to the first modification First, the light receiving and emitting device 200 according to the first modification will be described. FIG. 6 is a plan view schematically showing the light emitting / receiving device 200. 7 is a cross-sectional view taken along line VII-VII in FIG. In FIG. 6, the second electrode 113 is not shown for convenience.

  In the light emitting / receiving device 200, as shown in FIGS. 6 and 7, the first gain region 162 and the second gain region 164 form a gain region pair 266, and a plurality of gain region pairs 266 are arranged. A light receiving region 190 is provided corresponding to each of the plurality of gain region pairs 266. In the illustrated example, three gain region pairs 266 are provided, but the number is not particularly limited.

  A second separation groove 280 is formed between adjacent gain region pairs 266. As shown in FIG. 7, the bottom surface of the second separation groove 280 is positioned below the lower surface of the light emitting / receiving layer 106. The plurality of gain region pairs 266 are electrically separated from each other by the second separation groove 280.

  According to the light emitting / receiving device 200, higher output of light emission can be achieved compared to the example of the light receiving / emitting device 100. Further, according to the light emitting / receiving device 200, the plurality of gain region pairs 266 are electrically separated from each other by the second separation groove 280, so that the light output of each of the plurality of gain region pairs 266 can be monitored. it can. That is, the light amount detection can be performed individually for each of the plurality of gain region pairs 266.

(2) Light receiving and emitting device according to the second modification Next, a light receiving and emitting device 300 according to the second modification will be described. FIG. 8 is a plan view schematically showing the light emitting / receiving device 300. In FIG. 8, the second electrode 113 is not shown for convenience.

  In the example of the light receiving and emitting device 100, the second end surface 172 of the first gain region 162 and the fourth end surface 176 of the second gain region 164 overlap each other on the overlapping surface 178. The second side surface 107 is provided with a reflecting portion 130.

  In the light emitting / receiving device 200, as shown in FIG. 8, the second end surface 172 and the fourth end surface 176 are separated and do not overlap. Further, the second side surface 107 is not provided with a reflecting portion. Thereby, light can be emitted also from the second end surface 172 and the fourth end surface 176. Although not shown, the second side surface 172 may be covered with an antireflection portion.

  According to the light emitting / receiving device 200, the light 20 emitted from the two side surfaces 105 and 107 can be used. For example, the light density can be improved by reflecting the emitted light 20 upward (in the direction perpendicular to the paper surface in FIG. 8) using an optical axis conversion element (not shown).

(3) Light receiving and emitting device according to the third modification Next, a light receiving and emitting device 400 according to the third modification will be described. FIG. 9 is a plan view schematically showing the light emitting / receiving device 400. In FIG. 9, the second electrode 113 is not shown for convenience.

  In the example of the light receiving / emitting device 100, the light emitting region 160 of the light receiving / emitting layer 106 has the first gain region 162 and the second gain region 164.

  In the light emitting / receiving device 400, as shown in FIG. 9, the light emitting region 160 has a first gain region 162, a second gain region 164, and a third gain region 462.

  The first gain region 162 is provided to be inclined with respect to the normal line P from the first side surface 105 to the second side surface 107 in a plan view.

  The second gain region 164 is provided to be inclined with respect to the normal line P from the second side surface 107 to the third side surface 405 in a plan view. The third side surface 405 is a side surface of the light emitting / receiving layer 106 that is orthogonal to the first side surface 105 and the second side surface 107. In the illustrated example, the third side surface 405 connects the first side surface 105 and the second side surface 107.

  The third gain region 462 is provided to be inclined with respect to the normal line P from the first side surface 105 to the third side surface 405 in a plan view. The third gain region 462 can be parallel to the first gain region 162. The third gain region 462 includes a fifth end surface 470 provided on the first side surface 105 and a sixth end surface 472 provided on the third side surface 405. In the illustrated example, the fourth end surface 174 and the sixth end surface 472 completely overlap each other on the overlapping surface 478.

  For example, part of the light 10 generated in the first gain region 162 is reflected by the overlapping surface 178 and reaches the second gain region 164. Further, the light is further reflected (for example, totally reflected) by the overlapping surface 478, reaches the third gain region 462, and is emitted as the emitted light 20 from the fifth end surface 470. That is, the reflectance of the first side surface 105 is smaller than the reflectance of the second side surface 107 and the third side surface 405 in the wavelength band of light generated in the gain regions 162, 164, and 462. The light intensity of the light 10 can be amplified in the gain regions 162, 164, 462. The light 20 emitted from the first end face 170 and the light 20 emitted from the fifth end face 470 can travel in the same direction. The light 20 emitted from the first end face 170 and the light 20 emitted from the fifth end face 470 may travel in a converging direction.

  Although not shown, the light receiving region 190 may also be provided between the second gain region 164 and the third gain region 462. Alternatively, an opening may be provided in the light emitting / receiving layer 106 by, for example, etching, and a side surface of the light emitting / receiving layer 106 that partitions the opening may be a third side surface 405. Moreover, you may cover the 3rd side surface 405 with a reflection part.

  According to the light emitting / receiving device 400, the light 20 emitted from the first end face 170 and the light 20 emitted from the fifth end face 470 can travel in the same direction. Thereby, the light emitting / receiving device 400 can reduce the size of an optical system (not shown) (an optical system on which the emitted light 20 is incident), for example, as compared with a case where the two emitted lights travel in a diverging direction.

(4) Light receiving and emitting device according to the fourth modification Next, a light receiving and emitting device 500 according to the fourth modification will be described. FIG. 10 is a cross-sectional view schematically showing the light emitting / receiving device 500.

  In the example of the light receiving and emitting device 100, the so-called gain waveguide type has been described. On the other hand, the light emitting / receiving device 500 can be a so-called refractive index waveguide type.

  That is, in the light emitting / receiving device 500, as shown in FIG. 10, the contact layer 110 and a part of the second cladding layer 108 can form a columnar portion 511. The planar shape of the columnar portion 511 is the same as that of the gain regions 162 and 164. For example, the current path between the electrodes 112 and 113 is determined by the planar shape of the columnar portion 511, and as a result, the planar shape of the gain regions 162 and 164 is determined. Although not shown, the columnar portion 511 may be constituted by, for example, the contact layer 110, the second cladding layer 108, and the light emitting / receiving layer 106, and further includes the first cladding layer 104. May be. Moreover, the side surface of the columnar part 511 can also be inclined.

  The insulating part 116 can be provided on the side of the columnar part 511. The insulating part 116 can be in contact with the side surface of the columnar part 511. In the illustrated example, the upper surface of the insulating portion 116 is continuous with the upper surface of the contact layer 110. The current between the electrodes 112 and 113 can flow through the columnar portion 511 sandwiched between the insulating portions 116, avoiding the insulating portions 116. The insulating portion 116 can have a refractive index smaller than the refractive index of the light emitting / receiving layer 106. Thereby, light can be efficiently confined in the gain regions 162 and 164 in the planar direction.

4). Next, the projector 600 according to the present embodiment will be described. FIG. 11 is a diagram schematically showing the projector 600. In FIG. 11, for convenience, the casing constituting the projector 600 is omitted. The projector 600 includes the light emitting / receiving device according to the present invention. Hereinafter, an example in which the light emitting / receiving device 100 is used as the light emitting / receiving device according to the present invention will be described.

  In the projector 600, the red light source (light emitting / receiving device) 100R that emits red light, green light, and blue light, the green light source (light emitting / receiving device) 100G, and the blue light source (light emitting / receiving device) 100B are the light emitting / receiving device 100 described above. is there.

  The projector 600 includes transmissive liquid crystal light valves (light modulation devices) 604R, 604G, and 604B that modulate light emitted from the light sources 100R, 100G, and 100B according to image information, and liquid crystal light valves 604R, 604G, and 604B. A projection lens (projection device) 608 that magnifies and projects the image formed by the above-described method onto a screen (display surface) 610. In addition, the projector 600 can include a cross dichroic prism (color light combining unit) 606 that combines light emitted from the liquid crystal light valves 604R, 604G, and 604B and guides the light to the projection lens 608.

  Further, in order to make the illuminance distribution of the light emitted from the light sources 100R, 100G, and 100B uniform, the projector 600 is provided with uniformizing optical systems 602R, 602G, and 602B on the downstream side of the light paths from the light sources 100R, 100G, and 100B. The liquid crystal light valves 604R, 604G, and 604B are illuminated with light having a uniform illuminance distribution. The uniformizing optical systems 602R, 602G, and 602B are configured by, for example, a hologram 602a and a field lens 602b.

  The three color lights modulated by the liquid crystal light valves 604R, 604G, and 604B are incident on the cross dichroic prism 606. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 610 by the projection lens 606, which is a projection optical system, and an enlarged image is displayed.

  In the above example, a transmissive liquid crystal light valve is used as the light modulation device. However, a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such a light valve include a reflective liquid crystal light valve and a digital micromirror device. Further, the configuration of the projection optical system is appropriately changed depending on the type of light valve used.

  Further, the light receiving / emitting device 100 is a scanning type having scanning means that is an image forming device that displays an image of a desired size on a display surface by scanning light from the light receiving / emitting device 100 on a screen. The present invention can also be applied to a light source device of an image display device (projector).

  According to the projector 600, the light emitting / receiving device 100 can be used as the red light source 600R, the green light source 600G, and the blue light source 600B. In the light receiving and emitting device 100, the light emitting element and the light receiving element can be monolithically integrated as described above. Therefore, for example, it is possible to obtain a projector 600 that can reduce the number of parts and the manufacturing cost as compared with a case where a light receiving element is separately installed.

  In addition, embodiment mentioned above and a modification are examples, Comprising: It is not necessarily limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  Although the embodiments of the present invention have been described in detail as described above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

10 light, 20 light, 100 light emitting and receiving device, 102 substrate, 104 first cladding layer,
105 first side surface, 106 light receiving / emitting layer, 107 second side surface, 108 second cladding layer,
110 contact layer, 112 first electrode, 113 second electrode, 114 third electrode,
115 electrode layer, 116 insulating portion, 160 light emitting region, 162 first gain region,
164 second gain region, 170 first end face, 172 second end face, 174 third end face,
176 4th end surface, 180 1st separation groove, 180a Inner circumference of the 1st separation groove,
180b outer periphery of the first separation groove, 190 light receiving region, 200 light receiving and emitting device,
266 gain region pair, 280 second separation groove, 300 light emitting and receiving device, 400 light emitting and receiving device,
405 third side surface, 462 third gain region, 470 fifth end surface, 472 sixth end surface,
478 overlapping surface, 500 light emitting / receiving device, 511 columnar section, 600 projector,
602 homogenizing optical system, 602a hologram, 602b field lens,
604 liquid crystal light valve, 606 cross dichroic prism,
608 projection lens, 610 screen

Claims (8)

A first cladding layer;
A light emitting / receiving layer formed above the first cladding layer and having a light emitting region and a light receiving region;
A second cladding layer formed above the light emitting / receiving layer;
Including
The light emitting region and the light receiving region are partitioned by a first separation groove,
The light emitting region has a first gain region and a second gain region,
The distance between the first gain region and the second gain region decreases from the first side surface side of the light emitting / receiving layer toward the second side surface side of the light emitting / receiving layer parallel to the first side surface. ,
The first gain region and the second gain region are provided to be inclined with respect to a normal to the first side surface in a plan view,
The light receiving region is located between the first gain region and the second gain region,
By reducing the distance between the first gain region and the second gain region, light leaking from the first gain region and the second gain region reaches the light receiving region and is received. Light emitting device. In claim 1,
The distance between the light receiving region and the second side surface is smaller than the distance from the light receiving region to the first side surface. In claim 1 or 2,
The first gain region and the second gain region are provided from the first side surface to the second side surface,
In the wavelength band of light generated in the first gain region and the second gain region, the reflectance of the first side surface is smaller than the reflectance of the second side surface,
The light emitting / receiving device, wherein at least a part of an end surface of the first gain region on the second side surface side overlaps at least a part of an end surface of the second gain region on the second side surface side. In claim 1 or 2,
The first gain region and the second gain region are provided from the first side surface to the second side surface,
The end face on the second side surface side of the first gain region and the end surface on the second side surface side of the second gain region are separated from each other. In claim 1 or 2,
The first gain region is provided from the first side surface to the second side surface,
The second gain region is provided from the second side surface to the first side surface and the third side surface of the light receiving and emitting layer orthogonal to the second side surface,
The light emitting region further has a third gain region,
The third gain region is provided from the first side surface to the third side surface,
In the wavelength band of light generated in the first gain region, the second gain region, and the third gain region, the reflectance of the first side surface is smaller than the reflectance of the second side surface and the third side surface,
At least a part of the end surface of the first gain region on the second side surface side overlaps at least a part of the end surface of the second gain region on the second side surface side, and
At least a part of the end surface on the third side surface side of the second gain region overlaps with at least a part of the end surface on the third side surface side of the third gain region,
The light emitted from the end surface on the first side surface side of the first gain region and the light emitted from the end surface on the first side surface side of the third gain region proceed in the same direction or in a converging direction. , Light emitting and receiving device. In any of claims 1 to 5,
The first gain region and the second gain region form a gain region pair,
A plurality of the gain region pairs are arranged,
A second separation groove is formed between the adjacent gain region pairs,
The plurality of gain region pairs are electrically separated from each other by the second separation groove. In any one of Claims 1 thru | or 6.
A contact layer formed above the second cladding layer;
A first electrode electrically connected to the first cladding layer;
A second electrode in contact with the contact layer located above the first gain region and the second gain region;
A third electrode in contact with the first contact layer located above the light receiving region;
Further including
The planar shapes of the first gain region and the second gain region are the same as the planar shape of the contact surface between the second electrode and the contact layer,
The planar shape of the light receiving region is the same as the planar shape of the contact surface between the third electrode and the contact layer. A light emitting and receiving device according to any one of claims 1 to 7,
A light modulation device that modulates light emitted from the light emitting and receiving device according to image information;
A projection device for projecting an image formed by the light modulation element;
Including projector.

Images