Photoelectric element, light source module, optical engine, and XR glasses

Abstract

The technical problem of the present invention is to provide a photoelectric element that monitors input light and suppresses a decrease in efficiency of output light intensity with respect to the input light intensity. This photoelectric element (100) is provided with a substrate and an optical functional layer. The optical functional layer is provided with: optical input ports (21-1i); an optical branching unit (50-1) to which are connected a light incidence side waveguide (21-1) that guides visible light input from the optical input ports (21-1i), one monitoring optical waveguide (41-m), and two optical modulation optical waveguides (41-1, 41-2); a Mach-Zehnder type light modulation unit (40) that modulates the visible light guided by the two light modulation optical waveguides (41-1, 41-2); a 2 * 1 type optical multiplexing unit (50-2) that multiplexes the two visible lights modulated by the Mach-Zehnder type optical modulation unit (40); a light output-side waveguide (22-1) that guides the light multiplexed by the light multiplexing unit (50-2) to a light output port (22-1o); an optical output port (22-1o); and a monitoring light output port (41-mo).

Description

[0001] This application claims priority based on Special Application No. 2023-108108 filed in Japan on June 30, 2023, and the contents are cited here. Technical Field

[0002] The invention relates to a photoelectric element, a light source module, an optical engine and XR glasses. Background Art

[0003] Currently, in XR technologies such as VR (Virtual Reality) and AR (Augmented Reality), glasses-type terminals are being studied. In particular, in recent years, retinal scanning displays that allow users to recognize images by imaging two-dimensionally scanned light on the user's retina have attracted attention. In retinal scanning displays, generally speaking, three colors of visible light emitted from light sources such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes) corresponding to the colors R (red), G (green), and B (blue) are combined on one optical axis. The combined three-color visible light is transmitted to the image display unit. The image display unit performs two-dimensional scanning on the transmitted light and makes it incident on the user's pupil. The incident light is imaged on the user's retina, so that the user recognizes the image. In this case, the retina is the screen that displays the image.

[0004] Patent Document 1 discloses a signal generating unit of an image display device provided with a light detecting unit for detecting the amount of light of a remaining portion of light emitted from a light source to an optical fiber that is not incident on the optical fiber.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6728596 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the structure disclosed in Patent Document 1, an optical fiber is required between the light source and the light modulator.

[0010] In a PLC (Planar Lightwave Circuit) equipped with a light source such as an LD (Laser Diode), the temperature dependence of the light source becomes a problem. The light intensity fluctuation caused by the temperature of the LD causes the light intensity fluctuation of the emitted light. Therefore, it is necessary to branch the monitoring light from the main waveguide, feed back the light intensity fluctuation of the monitoring light to the control unit, and control the current applied to the LD.

[0011] In addition, the LN modulator in communication has the problem of DC drift and temperature drift (shift). From the perspective of long-term reliability, it is necessary to monitor the change of the operating point and feed it back to the DC control unit. Therefore, it is necessary to divide the light after passing through the interaction part formed with the electrode for applying the electric field to the waveguide in the Mach-Zehnder optical modulator into two branches and monitor the modulated light. Therefore, there is a structure such as using a 2x2 multimode interferometer (MMI) to divide the modulated light into two branches, which are divided into monitoring light and output light. At this time, there is the following problem, that is, the output light is only 1 / 2 of the input light at most.

[0012] In XR glasses, since they are used for a short time, the influence of DC drift and temperature drift of LN (lithium niobate (LiNbO3)) is very small and does not need to be considered. Therefore, it is sufficient to monitor only the temperature dependence of LD. The inventors have come up with the following structure, that is, the input light is divided into three branches, two of which are provided with electrodes to form a Mach-Zehnder type optical modulator, and the remaining one branch is output as monitoring light. With this structure, the maximum output light can reach 2 / 3 of the input light.

[0013] The present invention is made in view of the above situation, and its object is to provide a photoelectric element, a light source module, an optical engine and XR glasses, which can monitor input light and suppress the decrease in the efficiency of output light intensity relative to the input light intensity.

[0014] Methods used to solve problems

[0015] In order to solve the above problems, the present invention provides the following technical means.

[0016] Mode 1 of the present invention is a photoelectric element, which comprises: a substrate; and an optical functional layer, which is formed on the main surface of the substrate, and the optical functional layer has: an optical input port, which can input visible light emitted from a visible light laser light source; an optical branching portion, which is connected to a light incident side waveguide, a monitoring optical waveguide and a plurality of optical modulation optical waveguides, and the light incident side waveguide guides the visible light input from the optical input port; a Mach-Zehnder type optical modulation portion, which modulates the visible light guided in the plurality of optical modulation optical waveguides; an optical combining portion, which combines two visible lights modulated by the Mach-Zehnder type optical modulation portion; an optical output side waveguide, which guides the light combined by the optical combining portion to an optical output port; an optical output port, which outputs the light guided in the optical output side waveguide to the outside; and a monitoring optical output port, which outputs the light guided in the monitoring optical waveguide toward a photodetector.

[0017] A second aspect of the present invention is, in the optoelectronic device of the first aspect, wherein the plurality of light modulation optical waveguides are two light modulation optical waveguides.

[0018] A third aspect of the present invention is the photovoltaic element of the first or second aspect, wherein the substrate is made of a material different from lithium niobate, and the optical functional layer is made of lithium niobate.

[0019] A fourth aspect of the present invention is that, in any one of the optoelectronic elements of aspects 1 to 3, the optical branching section and the optical combining section are both parts constituting a multi-mode interferometer.

[0020] Mode 5 of the present invention is that in any photoelectric element in modes 1 to 4, there are: 3 optical input ports, which can input 3 visible lights with different wavelengths output from 3 visible light laser light sources respectively; and 3 optical output ports, which output 3 visible lights with different wavelengths to the outside.

[0021] Mode 6 of the present invention is that in any photoelectric element in modes 1 to 4, there is provided: 3 optical input ports, which can input 3 visible lights with different wavelengths outputted from 3 visible light laser light sources respectively; an optical combining unit, which combines the 3 visible lights with different wavelengths; and 1 optical output port, which outputs the light combined by the optical combining unit to the outside.

[0022] Mode 7 of the present invention is that in the optoelectronic element of mode 1, the multiple optical waveguides for light modulation are N1-1 (N1 is an integer greater than 3) optical waveguides for light modulation, and between the optical branching portion and the Mach-Zehnder type optical modulation portion, there is: an (N1-1)×2 type optical multiplexing branching portion having N1-1 optical waveguides for light modulation connected on the incident side and 2 optical waveguides connected to the Mach-Zehnder type optical modulation portion connected on the output side.

[0023] According to an eighth aspect of the present invention, in the photovoltaic element according to the seventh aspect, the substrate is made of a material different from lithium niobate, and the optical functional layer is made of lithium niobate.

[0024] A ninth aspect of the present invention is that, in the optoelectronic device of the seventh or eighth aspect, the optical branching section and the optical combining section are both parts constituting a multimode interferometer. In addition, the (N1-1)×2 type optical combining and branching section may be a part constituting a multimode interferometer.

[0025] Mode 10 of the present invention is that in any photoelectric element of modes 7 to 9, it has: 3 optical input ports, which can input 3 visible lights with different wavelengths outputted from 3 visible light laser light sources respectively; and 3 optical output ports, which output 3 visible lights with different wavelengths to the outside.

[0026] Mode 11 of the present invention is that in any photoelectric element in modes 7 to 9, there are: three optical input ports, which can input three visible lights with different wavelengths outputted from three visible light laser light sources respectively; an optical combining unit, which combines the three visible lights with different wavelengths; and one optical output port, which outputs the light combined by the optical combining unit to the outside.

[0027] Mode 12 of the present invention is that, in the optoelectronic element of mode 1, the plurality of optical waveguides for light modulation are 2N2 (N2 is an integer greater than 2) optical waveguides for light modulation, and between the optical branching portion and the Mach-Zehnder optical modulation portion, there are two N2×1 optical branching portions, and the two N2×1 optical branching portions are respectively connected to N2 of the 2N2 optical waveguides for light modulation on the incident side and to one optical waveguide connected to the Mach-Zehnder optical modulation portion on the output side.

[0028] A thirteenth aspect of the present invention is, in the photovoltaic element of the twelfth aspect, the substrate is made of a material different from lithium niobate, and the optical functional layer is made of lithium niobate.

[0029] A fourteenth aspect of the present invention is the optoelectronic device of the twelfth or thirteenth aspect, wherein the two N2×1 type optical branching sections constitute a multi-mode interferometer. In addition, the optical branching section and the optical combining section both constitute a multi-mode interferometer.

[0030] Mode 15 of the present invention is that in any photoelectric element in modes 12 to 14, there are: 3 optical input ports, which can input 3 visible lights with different wavelengths outputted from 3 visible light laser light sources respectively; and 3 optical output ports, which output 3 visible lights with different wavelengths to the outside.

[0031] Mode 16 of the present invention is that in any one of modes 12 to 14, the photoelectric element is provided with three optical input ports, which can input three visible lights with different wavelengths outputted from three visible light laser light sources respectively; an optical combining unit, which combines the three visible lights with different wavelengths; and one optical output port, which outputs the light combined by the optical combining unit to the outside.

[0032] Mode 17 of the present invention is a light source module comprising: any one of the electro-optical elements of modes 1 to 16; a visible light laser light source that outputs visible light input from the light input port; and a laser light intensity control unit that detects the monitoring light from the monitoring light output port by a light detector and adjusts the laser light intensity emitted from the visible light laser light source in accordance with the detected light intensity.

[0033] An eighteenth aspect of the present invention is an optical engine equipped with the light source module of the seventeenth aspect.

[0034] A nineteenth aspect of the present invention is an XR pair of glasses equipped with the light source module of the seventeenth aspect.

[0035] Effects of the Invention

[0036] According to the present invention, it is possible to provide a photoelectric element capable of monitoring input light and suppressing a decrease in efficiency of output light intensity relative to input light intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic plan view showing the photovoltaic element according to the first embodiment.

[0038] Figure 2 It is intercepted along X-X' Figure 1 A schematic cross-sectional view of the photovoltaic element shown.

[0039] Figure 3 It is a schematic plan view showing a photovoltaic element according to a second embodiment.

[0040] Figure 4 It is a schematic plan view showing a photovoltaic element according to a third embodiment.

[0041] Figure 5A It is a schematic plan view showing a modification of the photovoltaic element according to the first embodiment.

[0042] Figure 5B It is a schematic plan view showing another modified example of the photovoltaic element according to the first embodiment.

[0043] Figure 6 It is a schematic plan view showing a light source module according to a fourth embodiment.

[0044] Figure 7 It is a schematic plan view showing a light source module according to a fifth embodiment.

[0045] Figure 8 It is a schematic plan view showing a light source module according to a sixth embodiment.

[0046] Fig.9A It is a schematic plan view showing a modified example of the light source module according to the fourth embodiment.

[0047] Fig. 9B It is a schematic plan view showing another modified example of the light source module according to the fourth embodiment.

[0048] Fig.10 This is a conceptual diagram for explaining the optical engine and XR glasses involved in this embodiment.

[0049] Fig.11This is a conceptual diagram showing a form in which an image is directly projected on the retina by laser light emitted from the light source module involved in this embodiment.

[0050] Fig. 12A This is a top view of a model of a light branching portion and an optical waveguide connected thereto, which was simulated in Experimental Example 1.

[0051] Fig. 12B yes Fig. 12A Schematic diagram of the cross section along line AA.

[0052] Fig. 12C yes Fig. 12A Schematic diagram of the cross section of line BB.

[0053] Fig.13A This is a top view of a model of a light branching portion and an optical waveguide connected thereto, which were subjected to simulation of Experimental Example 2.

[0054] Fig. 13B yes Fig.13A Schematic diagram of the cross section along line AA.

[0055] Fig. 13C yes Fig.13A Schematic diagram of the cross section of line BB.

[0056] Fig.14A This is a top view of a model of a light branching portion and an optical waveguide connected thereto, which was simulated in Experimental Example 3.

[0057] Fig. 14B yes Fig.14A Schematic diagram of the cross section along line AA.

[0058] Fig. 14C yes Fig.14A Schematic diagram of the cross section of line BB.

[0059] Description of Reference Numerals

[0060] 10 substrates

[0061] 20 Light functional layer

[0062] 30 Visible light laser source

[0063] 40 Mach-Zehnder optical modulation unit

[0064] 50-1, 150-1, 250-1 optical branching unit

[0065] 150-2, 250-2 optical wave branching unit

[0066] 50-2, 150-3, 250-3 Photosynthetic Wavelength

[0067] 100, 101, 102, 200 photoelectric components

[0068] 300, 301, 302, 400, 1001 light source modules

[0069] 5001 Optical Engine

[0070] 10000XR glasses DETAILED DESCRIPTION

[0071] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings as appropriate. In the drawings used in the following description, in order to facilitate the understanding of the features, there are cases where the features are partially enlarged for convenience, and the dimensional ratios of the components are sometimes different from the actual ones. The materials, dimensions, etc. illustrated in the following description are only examples, and the present invention is not limited thereto, and can be implemented with appropriate changes within the scope of obtaining the effects of the present invention.

[0072] 〔Photoelectric components〕

[0073] Figure 1 It is a schematic plan view showing the photovoltaic element according to the first embodiment. Figure 2 It is intercepted along X-X' Figure 1 A schematic cross-sectional view of the photovoltaic element shown.

[0074] Figure 1 The optoelectronic element 100 shown in the figure comprises: a substrate 10, and an optical functional layer 20 formed on a main surface 10a of the substrate 10, wherein the optical functional layer 20 has: an optical input port 21-1i, which can input visible light emitted from a visible light laser light source; an optical branching portion 50-1, which is connected to a light incident side waveguide 21-1 for guiding the visible light input from the optical input port 21-1i, a monitoring optical waveguide 41-m, and two optical modulation optical waveguides 41-1 and 41-2; a Mach-Zehnder type optical modulation portion 40, which is connected to the two optical modulation optical waveguides 41- 1, modulate the visible light guided in 41-2; a 2-input 1-output type (2×1 type) optical combining unit 50-2, which combines the two visible lights modulated by the Mach-Zehnder type optical modulation unit 40; an optical output side waveguide 22-1, which guides the light combined by the optical combining unit 50-2 to the optical output port 22-1o; the optical output port 22-1o, which outputs the light guided in the optical output side waveguide 22-1 to the outside; and a monitoring optical output port 41-mo, which outputs the light guided in the monitoring optical waveguide 41-m toward the optical detector.

[0075] exist Figure 1In the optoelectronic element 100 shown, the laser light input from the visible light laser light source to the optical input port 21-1i is branched into three optical waveguides by the optical branching unit 50-1 of the 1-input 3-output type (1×3 type), and the light guided by one of the optical waveguides is used as monitoring light. In this structure, only 1 / 3 of the intensity (Pin) of the laser light input to the optical input port 21-1i can be used for monitoring (Pmonitor=1 / 3Pin), and the remaining 2 / 3 can be used for optical output (Pout=2 / 3Pin). That is, 2 / 3 of the intensity of the input light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 2 / 3.

[0076] exist Figure 1 The photoelectric element 100 shown has four side surfaces 100A, 100B, 100C, and 100D, the light input port 21-1i is arranged on the first side surface 100A, the light output port 22-1o is arranged on the third side surface 100C, and the monitoring light output port 41-mo is arranged on the second side surface 100B, but the structure is not limited to this. It is also possible to use a grating coupler, a reflector, etc. at the light input port 21-1i, the light output port 22-1o, and the monitoring light output port 41-mo, and input and output on the upper surface of the photoelectric element 100. In this case, the light input port 21-1i, the light output port 122-1o, and the monitoring light output port 141-mo do not need to be arranged on the four side surfaces 100A, 100B, 100C, and 100D, and can be arranged at any position on the upper surface of the photoelectric element 100.

[0077] The optical branching unit 50-1 and the optical combining unit 50-2 can use known optical branching units and optical combining units, and both can be multi-mode interferometers (MMI). By using a multi-mode interferometer, it is possible to reduce efficiency degradation caused by manufacturing variations.

[0078] exist Figure 1 In the photoelectric element 100 shown, there are two light modulation optical waveguides for guiding the light branched by the light branching unit 50 - 1 , but the two waveguides are just an example and are not limited to two, and may be three or more.

[0079] The Mach-Zehnder optical modulation unit 40 can use a known structure.

[0080] The electrodes 26 and 27 are electrodes for applying a modulation voltage to the Mach-Zehnder optical modulation unit 40. One end of the electrode 26 is connected to the power supply 131, and the other end is connected to the terminal resistor 132. One end of the electrode 27 is connected to the power supply 131, and the other end is connected to the terminal resistor 132. The power supply 131 is a part of a driving circuit for applying a modulation voltage to the Mach-Zehnder optical modulation unit 40.

[0081] exist Figure 1In the illustrated optoelectronic element 100 , the substrate 10 is made of a material different from lithium niobate, and the optical functional layer 20 can be made of lithium niobate.

[0082] By using a lithium niobate film as the optical functional layer 20 that propagates visible light, low loss in visible light propagation can be achieved.

[0083] In the optoelectronic element 100, when the refractive index difference between the waveguide core film and the waveguide cladding film is set to Δn, if the waveguide core film is set to lithium niobate, then compared with materials such as glass, Δn can be designed to be a larger value, and the curvature radius of the optical waveguide can be reduced. Furthermore, by using a multi-mode interference optical combining section, compared with the case of using a directional coupler, the increase in coupling length can be prevented, and both increased design freedom and miniaturization can be achieved.

[0084] The optical functional layer 20 has: an optical input port 21-1i; a light incident side waveguide 21-1; a monitoring optical waveguide 41-m; two optical modulation optical waveguides 41-1 and 41-2; an optical branching section 50-1, a Mach-Zehnder type optical modulation section 40; an optical combining section 50-2; an optical output side waveguide 22-1; an optical output port 22-1o; a waveguide core film 24 including a monitoring optical output port 41-mo; and a waveguide cladding (buffer) film 25 formed on the waveguide core film 24 in a manner covering the waveguide core film 24. Hereinafter, the reference numeral 24 may be used for the lithium niobate film.

[0085] Examples of the substrate 10 include a sapphire substrate, a Si substrate, and a thermally oxidized silicon substrate.

[0086] Since the optical functional layer 20 is composed of a lithium niobate (LiNbO3) film, there is no particular limitation as long as the refractive index is lower than that of the lithium niobate film. As a substrate capable of forming a single-crystal lithium niobate film as an epitaxial film, a sapphire single-crystal substrate or a silicon single-crystal substrate is preferred. The crystal orientation of the single-crystal substrate is not particularly limited. For example, a lithium niobate film oriented along the c-axis has a three-fold symmetry. Therefore, the single-crystal substrate of the base preferably has the same symmetry. In the case of a sapphire single-crystal substrate, a c-plane substrate is preferred, and in the case of a silicon single-crystal substrate, a (111)-plane substrate is preferred.

[0087] The lithium niobate film is, for example, a c-axis oriented lithium niobate film. The lithium niobate film is, for example, an epitaxial film grown epitaxially on the substrate 10. The epitaxial film is a single crystal film whose crystal orientation is made uniform by using a base substrate. The epitaxial film is a film having a single crystal orientation in the z direction and in the xy plane, and the crystals are uniformly oriented in the x-axis, y-axis, and z-axis directions. Whether the film formed on the substrate 10 is an epitaxial film can be proved by, for example, confirming the peak intensity and pole at the orientation position in 2θ-θ X-ray diffraction.

[0088] Specifically, when measuring by 2θ-θ X-ray diffraction, all peak intensities other than the target plane are set to be 10% or less, preferably 5% or less of the maximum peak intensity of the target plane. For example, in the case where the lithium niobate film is a c-axis oriented epitaxial film, the peak intensity other than the (00L) plane is 10% or less, preferably 5% or less of the maximum peak intensity of the (00L) plane. Here, (00L) is a general term for equivalent planes such as (001) and (002).

[0089] In addition, in the conditions for confirming the peak intensity of the above-mentioned orientation position, only the orientation in one direction is indicated. Therefore, even if the above-mentioned conditions are obtained, when the crystal orientation is not consistent within the plane, the intensity of the X-ray does not become high at a specific angle position, and the pole is not seen. For example, in the case where the lithium niobate film is a lithium niobate film, LiNbO3 has a trigonal crystal structure, and therefore, there are three poles of LiNbO3 (014) in the single crystal. In the case of lithium niobate, it is known that epitaxial growth is carried out in a so-called twin state in which the crystals are symmetrically combined by 180° rotation around the c-axis. In this case, it becomes a state in which two of the three poles are symmetrically combined, and therefore, the poles become six. In addition, in the case of forming a lithium niobate film on a silicon single crystal substrate of the (100) plane, the substrate becomes four-fold symmetric, and therefore, 4x3=12 poles are observed. In addition, in the present disclosure, a lithium niobate film epitaxially grown in a twin state is also included in the epitaxial film.

[0090] The composition of lithium niobate is Li x Nb y O z . A is an element other than Li, Nb, and O. x is greater than or equal to 0.5 and less than or equal to 1.2, preferably greater than or equal to 0.9 and less than or equal to 1.05. y is greater than or equal to 0 and less than or equal to 0.5. z is greater than or equal to 1.5 and less than or equal to 4.0, preferably greater than or equal to 2.5 and less than or equal to 3.5. Elements of A are, for example, K, Na, Rb, Cs, Be, Mg, Ca, Sr, Ba, Ti, Zr, Hf, V, Cr, Mo, W, Fe, Co, Ni, Zn, Sc, and Ce, and these elements may be combined in combination of two or more.

[0091] Alternatively, the lithium niobate film may be a lithium niobate single crystal thin film bonded to a substrate.

[0092] The thickness of the lithium niobate film is, for example, 2 μm or less. The thickness of the lithium niobate film is the thickness of the portion other than the ridge. The thickness of the lithium niobate film may be appropriately and optimally designed according to the wavelength used, the ridge shape, and the like.

[0093] The waveguide is a ridge protruding from the first surface 24A of the lithium niobate film 24. The first surface 24A is the upper surface of the portion (slab layer) of the lithium niobate film 24 other than the ridge.

[0094] The cross-sectional shapes of the monitoring optical waveguide 41-m and the two optical modulation optical waveguides 41-1 and 41-2 are rectangular, but any shape that can guide light may be used, for example, a trapezoid, a triangle, a semicircle, etc. The width Wa of the three ridges in the y direction is preferably 0.2 μm or more and 5.0 μm or less, and the height of the three ridges (the protruding height Ha from the first surface 24A) is preferably 0.1 μm or more and 1.0 μm or less, for example. The same is true for the other optical waveguides.

[0095] By making the cross-sectional size of the optical waveguide approximately the wavelength of the laser light, it is possible to propagate in a single mode.

[0096] Figure 3 1 is a schematic plan view showing a photovoltaic device according to Embodiment 2. Hereinafter, illustration and description of portions common to the photovoltaic device according to Embodiment 1 may be omitted.

[0097] Figure 3 The photoelectric element 101 shown in FIG. 1 comprises: a substrate 10 (see Figure 2 ), and formed on the main surface 10a of the substrate 10 (refer to Figure 2 ) of the optical functional layer 20 (refer to Figure 2 ), the optical functional layer 20 has: an optical input port 121-1i, which can input visible light emitted from a visible light laser light source; an optical branching portion 150-1, which is connected to a light incident side waveguide 121-1 for guiding the visible light input from the optical input port 121-1i, a monitoring optical waveguide 141-m, and three optical modulation optical waveguides 141-1, 141-2, and 141-3; a 3×2 type optical multiplexing branching portion 150-2, which is between the optical branching portion 150-1 and the Mach-Zehnder type optical modulation portion 140, and is connected to three optical modulation optical waveguides 141-1, 141-2, and 141-3 on the incident side, and is connected to an optical modulation optical waveguide connected to the Mach-Zehnder type optical modulation portion 140 on the output side. Optical waveguides 142-1, 142-2; a Mach-Zehnder optical modulation unit 140, which modulates the visible light guided in the two optical waveguides 142-1, 142-2 for optical modulation; a 2-input 1-output type (2×1 type) optical combining unit 150-3, which combines the two visible lights modulated by the Mach-Zehnder optical modulation unit 140; an optical output side waveguide 122-1, which guides the light combined by the optical combining unit 150-3 to the optical output port 122-1o; the optical output port 122-1o, which outputs the light guided in the optical output side waveguide 122-1 to the outside; and a monitoring optical output port 141-mo, which outputs the light guided in the monitoring optical waveguide 141-m toward the optical detector.

[0098] exist Figure 3In the photoelectric element 101 shown, the laser light input from the visible light laser light source to the optical input port 121-1i is branched into four optical waveguides by a 1-input 4-output type (1×4 type) optical branching unit 150-1, and the light guided by one of the optical waveguides is used as monitoring light. In this structure, only 1 / 4 of the intensity (Pin) of the laser light input to the optical input port 121-1i can be used for monitoring (Pmonitor=1 / 4Pin), and the remaining 3 / 4 can be used for optical output (Pout=3 / 4Pin). That is, 3 / 4 of the intensity of the input light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 3 / 4.

[0099] exist Figure 3 The photoelectric element 101 shown has four side surfaces 101A, 101B, 101C, and 101D, the light input port 121-1i is arranged on the first side surface 101A, the light output port 122-1o is arranged on the third side surface 101C, and the monitoring light output port 141-mo is arranged on the second side surface 101B, but the structure is not limited to this. It is also possible to use a grating coupler, a reflector, etc. at the light input port 121-1i, the light output port 122-1o, and the monitoring light output port 141-mo, and input and output on the upper surface of the photoelectric element 101. In this case, the light input port 121-1i, the light output port 122-1o, and the monitoring light output port 141-mo do not need to be arranged on the four side surfaces 101A, 101B, 101C, and 101D, and can be arranged at any position on the upper surface of the photoelectric element 101.

[0100] The optical branching unit 150-1, the 3×2 type optical multiplexing branching unit 150-2, and the optical multiplexing unit 150-3 can use known optical branching units, optical multiplexing branching units, and optical multiplexing units, and can all be multimode interferometers (MMI). By using a multimode interferometer, efficiency degradation caused by manufacturing variations can be reduced.

[0101] exist Figure 3 In the photoelectric element 101 shown, there are three optical waveguides for light modulation (optical waveguides 141-1, 141-2, and 141-3) for guiding the light branched by the light branching section 150-1, but three is an example and is not limited to three, and can be more than (N1-1) (N1 is an integer greater than 3). In this structure, only 1 / N1 of the intensity (Pin) of the laser input to the optical input port 121-1i can be used for monitoring (Pmonitor=1 / N1Pin), and the remaining (N1-1) / N1 can be used for light output (Pout=(N1-1) / N1Pin). That is, (N1-1) / N1 of the intensity of the input light can be used for output light, and the efficiency of the output light relative to the input light can be improved to (N1-1) / N1.

[0102] Figure 4 1 is a schematic plan view showing a photovoltaic device according to Embodiment 3. Hereinafter, illustration and description of portions common to the photovoltaic devices according to the above-mentioned embodiments may be omitted.

[0103] Figure 4 The photoelectric element 102 shown in FIG. 1 comprises: a substrate 10 (see Figure 2 ), and formed on the main surface 10a of the substrate 10 (refer to Figure 2 ) of the optical functional layer 20 (refer to Figure 2 ), the optical functional layer 20 has: an optical input port 221-1i, which can input visible light emitted from a visible light laser light source; an optical branching portion 250-1, which is connected to a light incident side waveguide 221-1 for guiding the visible light input from the optical input port 221-1i, a monitoring optical waveguide 241-m, and four optical modulation optical waveguides 241-11, 241-12, 241-21, and 241-22; two 2×1 type optical multiplexing branching portions 250-21 and 250-22, which are between the optical branching portion 250-1 and the Mach-Zehnder type optical modulation portion 240, and are connected to the optical modulation optical waveguides 241-11, 241-12, 241-21, and 241-22 on the incident side, and are connected to the Mach-Zehnder type on the output side. The optical modulator 240 is connected to optical waveguides 242-1 and 242-2 for optical modulation; a Mach-Zehnder optical modulator 240, which modulates the visible light guided in the two optical waveguides 242-1 and 242-2 for optical modulation; a 2-input 1-output type (2×1 type) optical combining unit 250-3, which combines the two visible lights modulated by the Mach-Zehnder optical modulator 240; an optical output side waveguide 222-1, which guides the light combined by the optical combining unit 250-3 to the optical output port 222-1o; the optical output port 222-1o, which outputs the light guided in the optical output side waveguide 222-1 to the outside; and a monitoring optical output port 241-mo, which outputs the light guided in the monitoring optical waveguide 241-m toward the optical detector.

[0104] exist Figure 4 In the photoelectric element 102 shown, the laser light input from the visible light laser light source to the optical input port 221-1i is branched into five optical waveguides by the optical branching section 250-1 of the 1-input 5-output type (1×5 type), and the light guided by one of the optical waveguides is used as monitoring light. In this structure, only 1 / 5 of the intensity (Pin) of the laser light input to the optical input port 221-1i can be used for monitoring (Pmonitor=1 / 5Pin), and the remaining 4 / 5 can be used for optical output (Pout=4 / 5Pin). That is, 4 / 5 of the intensity of the input light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 4 / 5.

[0105] exist Figure 4 The photoelectric element 102 shown has four side surfaces 102A, 102B, 102C, and 102D, the light input port 221-1i is arranged on the first side surface 102A, the light output port 222-1o is arranged on the third side surface 102C, and the monitoring light output port 241-mo is arranged on the second side surface 102B, but the structure is not limited to this. It is also possible to use a grating coupler, a reflector, etc. at the light input port 221-1i, the light output port 222-1o, and the monitoring light output port 241-mo, and input and output on the upper surface of the photoelectric element 102. In this case, the light input port 221-1i, the light output port 222-1o, and the monitoring light output port 241-mo do not need to be arranged on the four side surfaces 102A, 102B, 102C, and 102D, and can be arranged at any position on the upper surface of the photoelectric element 102.

[0106] The optical branching unit 250-1, two 2×1 optical multiplexing branching units 250-21, 250-22 and the optical multiplexing unit 250-3 can use known optical branching units, optical multiplexing branching units and optical multiplexing units, and can all be multimode interferometers (MMI). By using a multimode interferometer, efficiency degradation caused by manufacturing variations can be reduced.

[0107] The two optical multiplexing and branching units 250-21 and 250-22 are both 2×1 type optical multiplexing and branching units. However, when the optical branching unit 250-1 is configured to output to (2N2×1) optical waveguides, there are two N2×1 type optical multiplexing and branching units.

[0108] exist Figure 4 In the photoelectric element 102 shown, there are four optical waveguides for light modulation (optical waveguides 241-11, 241-12, 241-21, and 241-22) for guiding the light branched by the light branching section 250-1. However, four waveguides are only an example and are not limited to four. There can be more than 2N2 (N2 is an integer greater than 2). In this structure, only 1 / (2N2+1) of the intensity (Pin) of the laser input to the optical input port 221-1i can be used for monitoring (Pmonitor=1 / (2N2+1)Pin), and the remaining 2N2 / (2N2+1) can be used for light output (Pout=2N2 / (2N2+1)Pin). That is, 2N2 / (2N2+1) of the intensity of the input light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 2N2 / (2N2+1).

[0109] Figure 5AFIG. 1 is a schematic plan view showing a modified example of the photovoltaic element according to the first embodiment. In the following, the illustration and description of the parts common to the photovoltaic element according to the above embodiment may be omitted. Figure 1 and Figure 2 The photoelectric element described above is a structure having one light input port and one light output port, and modulating visible light output from one visible light laser light source, while this modified example is a structure having three light input ports capable of inputting three visible lights of different wavelengths output from three visible light laser light sources, and three light output ports for outputting the three visible lights of different wavelengths to the outside. The following description is made by taking the case where the three visible lights of different wavelengths are visible lights output from three colors of RGB as an example.

[0110] Here, the red (R) laser can use light with a peak wavelength of 600nm to 830nm, the green (G) laser can use light with a peak wavelength of 500nm to 600nm, and the blue (R) laser can use light with a peak wavelength of 380nm to 500nm.

[0111] Figure 5A The photoelectric element 200 shown in FIG. 1 includes a substrate 10 (see Figure 2 ), and formed on the main surface 10a of the substrate 10 (refer to Figure 2 ) of the optical functional layer 20 (refer to Figure 2 ).

[0112] The optical functional layer 20 has: an optical input port 21-1i, which can input visible light emitted from a red laser light source; an optical branching portion 50-11, which is connected to a light incident side waveguide 21-1 for guiding the red laser light input from the optical input port 21-1i, a monitoring optical waveguide 41-m, and two optical modulation optical waveguides 41-11 and 41-12; a Mach-Zehnder type optical modulation portion 40-1, which modulates the red laser light guided in the two optical modulation optical waveguides 41-11 and 41-12; and a 2 input 1 An output type (2×1 type) optical combining unit 50-21, which combines two red lasers modulated by the Mach-Zehnder type optical modulation unit 40-1; an optical output side waveguide 22-1, which guides the red laser combined by the optical combining unit 50-21 to the optical output port 22-1o; the optical output port 22-1o, which outputs the red laser guided in the optical output side waveguide 22-1 to the outside; and a monitoring optical output port 41-mo, which outputs the red laser guided in the monitoring optical waveguide 41-m toward the optical detector.

[0113] The optical functional layer 20 further comprises: an optical input port 21-2i, which can input visible light emitted from a green laser light source; an optical branching portion 50-12, which is connected to a light incident side waveguide 21-2 for guiding the green laser light input from the optical input port 21-2i, a monitoring optical waveguide 42-m, and two optical modulation optical waveguides 41-21 and 41-22; a Mach-Zehnder type optical modulation portion 40-2, which modulates the green laser light guided in the two optical modulation optical waveguides 41-21 and 41-22; and a light branching portion 50-13, which is connected to a light incident side waveguide 21-2 for guiding the green laser light input from the optical input port 21-2i, a monitoring optical waveguide 42-m, and two optical modulation optical waveguides 41-21 and 41-22. 1 output type (2×1 type) optical combining unit 50-22, which combines two green lasers modulated by the Mach-Zehnder type optical modulation unit 40-2; an optical output side waveguide 22-2, which guides the green laser combined by the optical combining unit 50-22 to the optical output port 22-2o; the optical output port 22-2o outputs the green laser guided in the optical output side waveguide 22-2 to the outside; and a monitoring optical output port 42-mo, which outputs the green laser guided in the monitoring optical waveguide 42-m toward the optical detector.

[0114] The optical functional layer 20 further comprises: an optical input port 21-3i, which can input visible light emitted from a blue laser light source; an optical branching portion 50-13, which is connected to a light incident side waveguide 21-3 for guiding the blue laser light input from the optical input port 21-3i, a monitoring optical waveguide 43-m, and two optical modulation optical waveguides 41-31 and 41-32; a Mach-Zehnder type optical modulation portion 40-3, which modulates the blue laser light guided in the two optical modulation optical waveguides 41-31 and 41-32; and a light branching portion 50-13, which is connected to a light incident side waveguide 21-3 for guiding the blue laser light input from the optical input port 21-3i, a monitoring optical waveguide 43-m, and two optical modulation optical waveguides 41-31 and 41-32. 1 output type (2×1 type) optical combining unit 50-23, which combines two blue lasers modulated by the Mach-Zehnder type optical modulation unit 40-3; an optical output side waveguide 22-3, which guides the blue laser combined by the optical combining unit 50-23 to the optical output port 22-3o; the optical output port 22-3o outputs the blue laser guided in the optical output side waveguide 22-3 to the outside; and a monitoring optical output port 43-mo, which outputs the blue laser guided in the monitoring optical waveguide 43-m to the optical detector.

[0115] exist Figure 5AIn the photoelectric element 200 shown, the red laser light input from the red laser light source to the optical input port 21-1i is branched into three optical waveguides by the optical branching section 50-11 of the 1-input 3-output type (1×3 type), and the light guided by one of the optical waveguides is used as monitoring light. In this structure, only 1 / 3 of the intensity (Pin) of the red laser light input to the optical input port 21-1i can be used for monitoring (Pmonitor=1 / 3Pin), and the remaining 2 / 3 can be used for optical output (Pout=2 / 3Pin). That is, 2 / 3 of the intensity of the input light of the red laser light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 2 / 3.

[0116] Similarly, the green laser light input from the green laser light source to the optical input port 21-2i is branched into three optical waveguides by the optical branching unit 50-12 of the 1-input 3-output type (1×3 type), and the light guided by one of the optical waveguides is used as monitoring light. In this structure, only 1 / 3 of the intensity (Pin) of the green laser light input to the optical input port 21-2i can be used for monitoring (Pmonitor=1 / 3Pin), and the remaining 2 / 3 can be used for optical output (Pout=2 / 3Pin). That is, 2 / 3 of the intensity of the input light of the green laser light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 2 / 3.

[0117] Similarly, the blue laser light input from the blue laser light source to the optical input port 21-3i is branched into three optical waveguides by the optical branching unit 50-13 of the 1-input 3-output type (1×3 type), and the light guided by one of the optical waveguides is used as monitoring light. In this structure, only 1 / 3 of the intensity (Pin) of the blue laser light input to the optical input port 21-3i can be used for monitoring (Pmonitor=1 / 3Pin), and the remaining 2 / 3 can be used for optical output (Pout=2 / 3Pin). That is, 2 / 3 of the intensity of the input light of the blue laser light can be used for output light, and the efficiency of the output light relative to the input light can be improved to 2 / 3.

[0118] exist Figure 5AThe photoelectric element 200 shown has four side surfaces 200A, 200B, 200C, and 200D, and the optical input ports 21-1i, 21-2i, and 21-3i are arranged on the first side surface 200A, the optical output ports 22-1o, 22-2o, and 22-3o are arranged on the third side surface 200C, and the monitoring optical output ports 41-mo, 42-mo, and 43-mo are arranged on the second side surface 200B, but the structure is not limited to this. A grating coupler, a reflector, or the like may be used for the optical input ports 21-1i, 21-2i, and 21-3i, the optical output ports 22-1o, 22-2o, and 22-3o, and the monitoring optical output ports 41-mo, 42-mo, and 43-mo, and input and output may be performed on the upper surface of the photoelectric element 200. At this time, the optical input ports 21-1i, 21-2i, 21-3i, the optical output ports 22-1o, 22-2o, 22-3o and the monitoring optical output ports 41-mo, 42-mo, 43-mo do not need to be set on the four sides 200A, 200B, 200C, 200D, but can be set at any position on the upper surface of the photoelectric element 200.

[0119] The optical branching units 50-11, 50-12, 50-13 and the optical combining units 50-21, 50-22, 50-23 can use known optical branching units and optical combining units, and can all be multimode interferometers (MMI). By using a multimode interferometer, efficiency degradation caused by manufacturing variations can be reduced.

[0120] exist Figure 5A In the optoelectronic element 200 shown, there are two optical waveguides for optical modulation of the light branched by the optical branching section 50-11, two optical waveguides for optical modulation of the light branched by the optical branching section 50-12, and two optical waveguides for optical modulation of the light branched by the optical branching section 50-13. However, two is just an example and is not limited to two, and can be more than three.

[0121] In the above, as a variation example of the photoelectric element involved in the first embodiment, a photoelectric element capable of modulating three visible lights of different wavelengths has been described. The photoelectric element involved in the second embodiment and the photoelectric element involved in the third embodiment are the same. A photoelectric element capable of modulating three different visible lights can be manufactured based on the photoelectric element capable of modulating one wavelength of visible light.

[0122] Figure 5B FIG. 1 is a schematic plan view showing another modified example of the photovoltaic element according to the first embodiment. In the following, the illustration and description of the parts common to the photovoltaic element according to the above embodiment may be omitted. Figure 5AIn the example shown, three optical output ports are provided for outputting three visible lights of different wavelengths to the outside, and each visible light is output from the three optical output ports. Figure 5B The example shown is a structure that has a combining unit for combining three visible lights of different wavelengths and an optical output port for outputting the combined light to the outside, and outputs the three visible lights of different wavelengths after combining them. The following description is made by taking the case where the three visible lights of different wavelengths are visible lights output from a visible light laser light source of RGB three colors as an example.

[0123] Figure 5B The photoelectric element 201 shown in FIG. 1 includes: a substrate 10 (see Figure 2 ), and formed on the main surface 10a of the substrate 10 (refer to Figure 2 ) of the optical functional layer 20 (refer to Figure 2 ).

[0124] The optical functional layer 20, in addition to Figure 5A In addition to the same structure as the optoelectronic element 200 shown, it also has: a 3-input 1-output type optical combining section 50-31, which takes the optical output side waveguide 22-1 for guiding the red laser combined by the optical combining section 50-21, the optical output side waveguide 22-2 for guiding the green laser combined by the optical combining section 50-22, and the optical output side waveguide 22-3 for guiding the blue laser combined by the optical combining section 50-23 as inputs, combines these RGB lasers and outputs them to the optical output side waveguide 23-1; and an optical output port 23-1o, which outputs the combined RGB light guided in the optical output side waveguide 23-1 to the outside.

[0125] exist Figure 5B In the photoelectric element 201 shown, the light intensity of the monitoring light branch of each RGB laser is only 1 / 3 (Pmonitor=1 / 3Pin) of the intensity (Pin) of each RGB laser input to each optical input port. Figure 5A The same as the optoelectronic element 200 shown. Figure 5A As with the photoelectric element 200 shown, 2 / 3 of the intensity of the input light of each of the RGB lasers can be used for the output light, and the efficiency of the output light relative to the input light is improved to 2 / 3.

[0126] exist Figure 5BThe photoelectric element 201 shown has four side surfaces 201A, 201B, 201C, and 201D, and the optical input ports 21-1i, 21-2i, and 21-3i are arranged on the first side surface 201A, the optical output port 23-1o is arranged on the third side surface 201C, and the monitoring optical output ports 41-mo, 42-mo, and 43-mo are arranged on the second side surface 201B, but the present invention is not limited to such a structure. A grating coupler, a reflector, or the like may be used for the optical input ports 21-1i, 21-2i, and 21-3i, the optical output port 23-1o, and the monitoring optical output ports 41-mo, 42-mo, and 43-mo, and input and output may be performed on the upper surface of the photoelectric element 201. At this time, the optical input ports 21-1i, 21-2i, 21-3i, the optical output port 23-1o and the monitoring optical output ports 41-mo, 42-mo, 43-mo do not need to be set on the four side surfaces 201A, 201B, 201C, 201D, but may be set at any position on the upper surface of the photoelectric element 201.

[0127] The optical combiner 50-31 can also use known optical branching parts and optical combiners like the optical branching parts 50-11, 50-12, 50-13 and the optical combiners 50-21, 50-22, 50-23, and can be a multimode interferometer (MMI). By using a multimode interferometer, efficiency degradation caused by manufacturing variations can be reduced.

[0128] As another variation example of the photoelectric element involved in the first embodiment, a photoelectric element capable of modulating three visible lights of different wavelengths has been described above. The photoelectric element involved in the second embodiment and the photoelectric element involved in the third embodiment are the same. A photoelectric element capable of modulating three different visible lights can be manufactured based on the photoelectric element capable of modulating one wavelength of visible light.

[0129] 〔Light source module〕

[0130] Figure 6 1 is a schematic plan view showing a light source module according to Embodiment 4. Hereinafter, illustration and description of portions common to the above-mentioned configuration may be omitted.

[0131] Figure 6 The light source module 300 shown has: Figure 1 The photoelectric element 100 shown; the visible light laser light source 30 that outputs visible light input from the light input port 21-1i; and the laser intensity control unit 80, which detects the monitoring light from the monitoring light output port 41-mo by the light detector 70, and adjusts the laser intensity emitted from the visible light laser light source 30 correspondingly to the detected light intensity.

[0132] As the visible light laser light source 30, various laser elements can be used. For example, commercially available laser diodes (LDs) of red light, green light, blue light, etc. can be used. Red light can use light with a peak wavelength of 600 nm to 830 nm, green light can use light with a peak wavelength of 500 nm to 600 nm, and blue light can use light with a peak wavelength of 380 nm to 500 nm.

[0133] As the photodetector 70 , a known photodetector can be used.

[0134] The laser intensity control unit 80 can control the intensity of laser light by controlling the drive current of the visible light laser light source 30 using a signal based on the light intensity of the monitor light detected by the photodetector 70 .

[0135] exist Figure 6 In the light source module 300 shown, current modulation of the visible light laser light source and voltage modulation of the Mach-Zehnder optical modulation unit can be used together.

[0136] Figure 7 1 is a schematic plan view showing a light source module according to Embodiment 5. Hereinafter, illustration and description of portions common to the above-mentioned configuration may be omitted.

[0137] Figure 7 The light source module 301 shown has: Figure 3 The photoelectric element 101 shown; the visible light laser light source 30 that outputs visible light input from the optical input port 121-1i; and the laser intensity control unit 80, which detects the monitoring light from the monitoring light 141-mo by the light detector 70, and adjusts the laser intensity emitted from the visible light laser light source 30 correspondingly to the detected light intensity.

[0138] Figure 7 The light source module 301 shown in FIG. Figure 6 Like the light source module 300 shown in the figure, the current modulation of the visible light laser light source and the voltage modulation of the Mach-Zehnder type optical modulation unit can be used together.

[0139] Figure 8 1 is a schematic plan view showing a light source module according to Embodiment 6. Hereinafter, illustration and description of portions common to the above-mentioned configuration may be omitted.

[0140] Figure 8 The light source module 302 shown has: Figure 4The photoelectric element 102 shown; the visible light laser light source 30 that outputs visible light input from the optical input port 221-1i; and the laser intensity control unit 80, which detects the monitoring light from the monitoring light 241-mo by the light detector 70 and adjusts the laser intensity emitted from the visible light laser light source 30 correspondingly to the detected light intensity.

[0141] Figure 8 The light source module 302 shown in FIG. Figure 6 The light source module 300 shown, Figure 7 Like the light source module 301 shown, it is possible to use both the current modulation of the visible light laser light source and the voltage modulation of the Mach-Zehnder type optical modulation unit.

[0142] Fig.9A 1 is a schematic plan view showing a modified example of the light source module according to the fourth embodiment. In the following, illustration and description of parts common to the above-mentioned configuration may be omitted.

[0143] Fig.9A The light source module 400 shown has: Figure 5A The photoelectric element 200 shown; a red laser light source 30-1 that outputs a red laser input from the light input port 21-1i; a green laser light source 30-2 that outputs a green laser input from the light input port 21-2i; a blue laser light source 30-3 that outputs a blue laser input from the light input port 21-3i; and a laser intensity control unit 180, which detects the respective monitoring lights from the monitoring light output port 41-mo, the monitoring light output port 42-mo and the monitoring light output port 43-mo by a light detector 170, and is capable of independently adjusting the light intensity of each laser emitted from the red laser light source 30-1, the green laser light source 30-2 and the blue laser light source 30-3 in accordance with the detected light intensity.

[0144] According to the above description, Fig.9A The light source module 400 shown in the figure has as a photoelectric element Figure 5A The photoelectric element 200 is shown. Fig.9A In Figure 5A The components denoted by the reference numerals used in the drawings are common components, and their description is omitted.

[0145] As the red laser light source 30-1, the green laser light source 30-2, and the blue laser light source 30-3, various laser elements can be used. For example, commercially available laser diodes (LD) emitting red light, green light, blue light, etc. can be used.

[0146] In the light source module 400 , the red laser light source 30 - 1 , the green laser light source 30 - 2 , and the blue laser light source 30 - 3 are arranged on the upper surface of the sub carrier 120 with intervals therebetween in a direction substantially orthogonal to the emission direction of the light emitted from each laser light source.

[0147] When the red laser source 30-1, the green laser source 30-2 and the blue laser source 30-3 are laser diodes, they can be mounted as bare chips on the submount 120. The submount 120 is made of, for example, aluminum nitride (AlN), aluminum oxide (Al2O3), silicon (Si), or the like.

[0148] The sub-carrier 120 can be configured to be directly bonded to the substrate 10 via a metal bonding layer. According to this structure, spatial coupling and optical fiber coupling are not performed, thereby enabling further miniaturization. Fig.9A In the embodiment, the red laser light source 30 - 1 , the green laser light source 30 - 2 , and the blue laser light source 30 - 3 are mounted on one sub-carrier 120 , but each light source may be mounted on a different sub-carrier.

[0149] By setting the sub-carrier 120 and the substrate 10 as a structure joined via a metal bonding layer, the relative position of the sub-carrier 120 and the substrate 10 can be adjusted during manufacturing, and the optical axis position of the laser can be aligned (active alignment) in such a way that the optical axis of each visible light laser light source coincides with the axis of the light incident side waveguide 21-1, the light incident side waveguide 21-2, and the light incident side waveguide 21-3.

[0150] As the photodetector 170 , a well-known photodetector can be used.

[0151] Laser intensity control unit 180 can control the laser intensity by controlling the drive current of red laser source 30 - 1 , green laser source 30 - 2 , and blue laser source 30 - 3 using a known control system based on the light intensity of each monitor light detected by photodetector 170 .

[0152] The light emitting surfaces (at the Fig.9A, the light emitting surface of the red laser light source 30-1 is indicated by the reference numeral 31. ) and the light incident surface (side surface) 200A of the photoelectric element 200 are arranged at a prescribed interval. The light incident surface 200A is opposite to the light exit surface 31, and there is a gap S between the light exit surface 31 and the light incident surface 200A in the x direction. The light source module 400 is exposed to the air, so the gap S is filled with air. Since the gap S is filled with the same gas (air), it is easy for the various colors of light emitted from the red laser light source 30-1, the red laser light source 30-2, and the blue laser light source 30-3 to be incident on the incident path in a state that satisfies the prescribed coupling efficiency. When the light source module 400 is used for XR glasses such as AR glasses and VR glasses, the size of the gap (interval) S in the x direction is, for example, greater than 0μm and less than 5μm, depending on the amount of light required by XR glasses such as AR glasses and VR glasses.

[0153] For example, in a retinal projection display, in order to display an image in a desired color, it is necessary to independently modulate the intensity of each of the three colors RGB that represent visible light at high speed.

[0154] If the above modulation is performed only with a visible light laser light source (current modulation), the load on the IC that controls these modulations will increase, but Fig.9A In the light source module 400 shown, modulation (voltage modulation) performed by a Mach-Zehnder light modulator can also be used. In this case, coarse adjustment can be performed by current (visible light laser light source) and fine adjustment can be performed by voltage (Mach-Zehnder light modulator). In addition, coarse adjustment can be performed by voltage (Mach-Zehnder light modulator) and fine adjustment can be performed by current (visible light laser light source). Preferably, since fine adjustment by voltage has better responsiveness, the former is adopted when responsiveness is emphasized, and since fine adjustment by current can suppress power consumption with low current, the latter is adopted when power consumption is suppressed. In addition, in the Mach-Zehnder light modulator, since high-speed modulation at a frequency of more than gigahertz can be performed, a high-resolution image can be obtained.

[0155] In the above, as a variation example of the light source module involved in the fourth embodiment, a light source module capable of modulating three visible lights with different wavelengths has been described. The photoelectric element involved in the fifth embodiment and the light source module involved in the sixth embodiment are the same. A light source module capable of modulating three different visible lights can be manufactured based on the light source module capable of modulating one wavelength of visible light.

[0156] Fig. 9B FIG. 1 is a schematic plan view showing another modified example of the light source module according to the fourth embodiment. In the following, the illustration and description of the parts common to the above-mentioned structure are sometimes omitted. Fig.9A In the example shown, the photoelectric element 200 has three optical output ports for outputting three visible lights of different wavelengths to the outside, and is configured to output the three visible lights from the three optical output ports. Fig. 9B In the example shown, the photoelectric element 201 is a structure that includes a combining unit for combining three visible lights of different wavelengths and an optical output port for outputting the combined light to the outside, and outputs the three visible lights of different wavelengths after combining them. The following description will be made by taking the case where the three visible lights of different wavelengths are visible lights output from a visible light laser light source of RGB three colors as an example.

[0157] Fig. 9B The light source module 500 shown has: Figure 5B The photoelectric element 201 shown; a red laser light source 30-1 that outputs a red laser input from the light input port 21-1i; a green laser light source 30-2 that outputs a green laser input from the light input port 21-2i; a blue laser light source 30-3 that outputs a blue laser input from the light input port 21-3i; and a laser intensity control unit 180, which detects the respective monitoring lights from the monitoring light output port 41-mo, the monitoring light output port 42-mo and the monitoring light output port 43-mo by the light detector 170, and can independently adjust the light intensity of each laser emitted from the red laser light source 30-1, the green laser light source 30-2 and the blue laser light source 30-3 in accordance with the detected light intensity.

[0158] According to the above description, Fig. 9B The light source module 500 shown in the figure has as a photoelectric element Figure 5B The photoelectric element 200 is shown. Fig. 9B In Figure 5B The components denoted by the reference numerals used in the drawings are common components, and their description is omitted.

[0159] 〔Optical Engine〕

[0160] In this specification, an optical engine includes: a plurality of light sources; an optical system including a combining unit that combines a plurality of light beams emitted from the plurality of light sources into a single beam of light; a light scanning mirror that changes the angle of the light emitted from the optical system and reflects it in an image display manner; and a control element that controls the light scanning mirror.

[0161] Fig.10 , a conceptual diagram for explaining an optical engine 5001 of this embodiment is shown. The diagram shows a state where the optical engine 5001 is provided in a frame 10010 of glasses. Reference numeral L denotes image display light.

[0162] The optical engine 5001 includes a visible light source module 1001 and a light scanning mirror 3001. As the visible light source module 1001 included in the optical engine 5001, the visible light source module according to the above-described embodiment is used.

[0163] The laser light emitted from the visible light source module 1001 mounted on the eyeglass frame is reflected and scanned by the light scanning mirror and enters the human eye, thereby projecting a direct image (video) on the retina.

[0164] The light scanning mirror 3001 is, for example, a MEMS mirror. In order to project a 2D image, it is preferably a two-axis MEMS mirror that oscillates so as to change the angle in the horizontal direction (X direction) and the vertical direction (Y direction) to reflect the laser light.

[0165] The optical engine 5001 includes a collimator lens 2001a, a slit 2001b, and an ND filter 2001c as an optical system for optically processing the laser light emitted from the visible light source module 1001. This optical system is an example, and other structures are also possible.

[0166] The optical engine 5001 includes a laser driver 1100 , a light scanning mirror driver 1200 , and a video controller 1300 for controlling these drivers.

[0167] 〔XR glasses〕

[0168] In the XR glasses according to the present embodiment, any of the light source modules according to the above-mentioned embodiments is mounted on the glasses.

[0169] XR glasses (glasses) are glasses-type terminals. XR is a general term for virtual reality (VR: Virtual Reality), augmented reality (AR: Augmented Reality), and mixed reality (Mixed Reality).

[0170] Fig.10 , a conceptual diagram for illustrating the XR glasses involved in this embodiment is shown.

[0171] Fig.10 In the XR glasses 10000 shown, a visible light source module 1001 is mounted on a frame 10010. Reference numeral L denotes image display light.

[0172] exist Fig.10 In the embodiment, the visible light source module 1001, the light scanning mirror 3001, and the optical system 2001 connecting the visible light source module 1001 and the light scanning mirror 3001 are sometimes collectively referred to as an optical engine 5001. As the visible light source module 1001, the light source module according to the above-mentioned embodiment is used.

[0173] As the light source of the visible light source module 1001 , for example, a light source including an RGB laser light source including a red laser light source 60 - 1 , a green laser light source 60 - 2 , and a blue laser light source 60 - 3 can be used.

[0174] like Fig.11 As shown, the laser light emitted from the visible light source module 1001 mounted on the eyeglass frame can be reflected by the light scanning mirror 3001 and enter the human eyeball E, thereby projecting a direct image (video) on the retina M.

[0175] By providing an eye tracking mechanism, it is possible to perform eye tracking and project a direct image on the retina. As the eye tracking mechanism, a known mechanism can be used.

[0176] The light scanning mirror 3001 is, for example, a MEMS mirror. In order to project a 2D image, a two-axis MEMS mirror that oscillates so as to change the angle in the horizontal direction (X direction) and the vertical direction (Y direction) to reflect the laser light is preferable.

[0177] The optical system 2001 for optically processing the laser light emitted from the visible light source module 1001 includes a collimator lens 2001a, a slit 2001b, and an ND filter 2001c. This optical system is only an example, and other structures may be used.

[0178] The optical engine 5001 includes a laser driver 1100, a light scanning mirror driver 1200, and a video controller 1300 for controlling these drivers.

[0179] [Example]

[0180] Hereinafter, the present invention will be described in further detail using examples. However, the present invention is not limited to the examples shown below.

[0181] (Experimental Example 1)

[0182] for Figure 1 The 1-input 3-output optical branching unit shown in the figure is Figures 12A to 12C The parameters shown in the figure are calculated for each of RGB through simulation: the efficiency (Pout / Pin) of the output light intensity (Pout) relative to the input light intensity (Pin), and the ratio (Pmonitor / Pin) of the monitor light intensity relative to the input light intensity (Pin). The output light intensity is obtained from two optical waveguides (equivalent to Figure 1 The monitoring light intensity is the sum of the light intensities outputted from the monitoring optical waveguide (equivalent to Figure 1The simulation software used was Fimmwave (PhotonDesign). The wavelengths of RGB were set to 637nm, 520nm and 455nm respectively.

[0183] like Fig. 12A As shown in the figure, the 1-input 3-output optical branching unit (equivalent to Figure 1 The length of the reference numeral 50-1) is set to L, and the width is set to W. L and W are adjusted to make Pout / Pin and Pmonitor / Pin become 2 / 3 and 1 / 3 respectively.

[0184] Fig. 12B yes Fig. 12A Schematic diagram of the cross section of line AA, Fig. 12C yes Fig. 12A Schematic diagram of the cross section of line BB.

[0185] In terms of materials, the substrate (equivalent to Figure 2 10) is set to sapphire, the waveguide core film (equivalent to Figure 2 24) is set as a lithium niobate film, and the waveguide cladding film (equivalent to Figure 2 25) is set as a SiO2 film.

[0186] For a 1-input 3-output type optical branching unit and a light incident side waveguide (equivalent to Figure 1 21-1), monitoring optical waveguide (equivalent to Figure 1 41-m), and an optical waveguide for light modulation (equivalent to Figure 1 The shape and size of the reference numerals 41-1, 41-2) are as follows: Figures 12A to 12C As shown in the figure, the shape of the 1-input 3-output optical branching part, the light incident side waveguide, the monitoring optical waveguide, and the optical modulating optical waveguide is set to a structure with a trapezoidal cross section and a 0.15 μm thick flat plate structure. The width of the upper base of the light incident side waveguide, the monitoring optical waveguide, and the optical modulating optical waveguide is set to 2 μm, the inclination angle of the side is set to 80°, and the distance from the main surface of the substrate 10 (equivalent to Figure 2 The thickness (height) of the reference numeral 10A) was set to 0.7 μm. The interval between the monitoring optical waveguide and the two light modulation optical waveguides was set to 4 μm.

[0187] Table 1 shows the length and width of the obtained 1-input 3-output optical branching portion, as well as Pout / Pin and Pmonitor / Pin.

[0188] [Table 1]

[0189]

[0190] As shown in Table 1, for any visible light of RGB, when the width W of the 1-input 3-output optical branching portion is set to 12 μm, by setting the length L to 169 μm, 212 μm, and 246 μm, the light output efficiency (Pout / Pin) and the monitor light ratio (Pmonitor / Pin) can be made 0.66 and 0.33.

[0191] According to the above results, use Figure 5A The optoelectronic element shown can make Pout / Pin and Pmonitor / Pin respectively 2 / 3 and 1 / 3 for any visible light of RGB.

[0192] (Experimental Example 2)

[0193] for Figure 3 The 1-input 4-output optical branching unit shown in the figure is Figures 13A to 13C The parameters shown in are used to calculate, through simulation, the efficiency (Pout / Pin) of the output light intensity (Pout) relative to the input light intensity (Pin), and the ratio (Pmonitor / Pin) of the monitor light intensity relative to the input light intensity (Pin) for R.

[0194] like Fig.13A As shown in the figure, the 1-input 4-output optical branching unit (equivalent to Figure 3 The length of the reference numeral 150-1) is set to L, and the width is set to W. L and W are adjusted to make Pout / Pin and Pmonitor / Pin become 3 / 4 and 1 / 4 respectively.

[0195] Fig. 13B yes Fig.13A Schematic diagram of the cross section of line AA, Fig. 13C yes Fig.13A Schematic diagram of the cross section of line BB.

[0196] For a 1-input 4-output type optical branching unit and a light incident side waveguide (equivalent to Figure 3 Reference numeral 121-1), monitoring optical waveguide (equivalent to Figure 3 141-m), and an optical waveguide for light modulation (equivalent to Figure 3 The shapes and sizes of the reference numerals 141-1, 141-2, 141-3) are as shown in FIG. Figures 13A to 13CAs shown in the figure. As for the shape, the 1-input 4-output optical branching part, the light incident side waveguide, the monitoring optical waveguide and the optical modulating optical waveguide are all set to have a structure of a flat plate with a cross section of a trapezoidal shape and a thickness of 0.15 μm. The width of the upper base of the light incident side waveguide, the monitoring optical waveguide and the optical modulating optical waveguide is set to 2 μm, the inclination angle of the side is set to 80°, and the distance from the main surface of the substrate 10 (equivalent to Figure 2 The thickness (height) of the reference numeral 10A) was set to 0.7 μm. The intervals between the monitoring optical waveguide and the three light modulation optical waveguides were set to 4 μm.

[0197] Table 2 shows the length and width of the obtained 1-input 4-output optical branching portion, as well as Pout / Pin and Pmonitor / Pin.

[0198] [Table 2]

[0199]

[0200]

[0201] As shown in Table 2, for R, when the width W of the 1-input 4-output optical branching portion is set to 16 μm, by setting the length L to 223 μm, the optical output efficiency (Pout / Pin) and the monitor light ratio (Pmonitor / Pin) can be set to 0.74 and 0.24.

[0202] (Experimental Example 3)

[0203] for Figure 4 The 1-input 5-output optical branching unit shown in the figure is Figures 14A to 14C The parameters shown are calculated by simulation for R: the efficiency (Pout / Pin) of the output light intensity (Pout) relative to the input light intensity (Pin), and the ratio (Pmonitor / Pin) of the monitor light intensity relative to the input light intensity (Pin).

[0204] like Fig.14A As shown in the figure, the 1-input 5-output optical branching unit (equivalent to Figure 4 The length of the reference numeral 150-1) is set to L, and the width is set to W. L and W are adjusted to make Pout / Pin and Pmonitor / Pin become 3 / 4 and 1 / 4 respectively.

[0205] Fig. 14B yes Fig.14A Schematic diagram of the cross section of line AA, Fig. 14C yes Fig.14A Schematic diagram of the cross section of line BB.

[0206] For a 1-input 5-output type optical branching unit, and a light incident side waveguide (equivalent to Figure 4 Reference numeral 221-1), monitoring optical waveguide (equivalent to Figure 4 41-m), and an optical waveguide for light modulation (equivalent to Figure 4 The shapes and sizes of the reference numerals 241-11, 241-12, 241-21, 241-22) are as shown in FIG. Figures 14A to 14C As shown in the figure. As for the shape, the 1-input 5-output optical branching part, the light incident side waveguide, the monitoring optical waveguide and the optical modulating optical waveguide are all set to have a structure of a flat plate with a cross section of a trapezoidal shape and a thickness of 0.15 μm. The width of the upper base of the light incident side waveguide, the monitoring optical waveguide and the optical modulating optical waveguide is set to 2 μm, the inclination angle of the side is set to 80°, and the distance from the main surface of the substrate 10 (equivalent to Figure 2 The thickness (height) of the reference numeral 10A) was set to 0.7 μm. The intervals between the monitoring optical waveguide and the four light modulation optical waveguides were set to 4 μm.

[0207] Table 2 shows the length and width of the obtained 1-input 5-output optical branching portion, as well as Pout / Pin and Pmonitor / Pin.

[0208] [Table 3]

[0209]

[0210] As shown in Table 3, for R, when the width W of the 1-input 5-output optical branching portion is set to 20 μm, by setting the length L to 278 μm, the optical output efficiency (Pout / Pin) and the monitor light ratio (Pmonitor / Pin) can be set to 0.79 and 0.19.

Claims

1. An electro-optical element, wherein: have: substrate; and a light functional layer formed on the main surface of the substrate, The optical functional layer has: An optical input port capable of inputting visible light emitted from a visible light laser light source; an optical branching section to which a light incident side waveguide, a monitoring optical waveguide, and a plurality of optical modulation optical waveguides are connected, wherein the light incident side waveguide guides the visible light input from the optical input port; a Mach-Zehnder type optical modulation unit for modulating the visible light guided through the plurality of optical waveguides for light modulation; a light combining unit for combining two visible lights modulated by the Mach-Zehnder light modulation unit; An optical output side waveguide, which guides the light combined by the optical combining unit to the optical output port; an optical output port for outputting the light guided in the optical output side waveguide to the outside; and The monitoring light output port is configured to output the light guided through the monitoring light waveguide toward the photodetector.

2. The electro-optical element according to claim 1, wherein The plurality of light modulation optical waveguides are two light modulation optical waveguides.

3. The electro-optical element according to claim 2, wherein: The substrate is made of a material different from lithium niobate, and the optical functional layer is made of lithium niobate. The optical branching section and the optical combining section are both parts constituting a multi-mode interferometer.

4. The electro-optical element according to claim 3, wherein: have: three optical input ports capable of inputting three visible lights of different wavelengths respectively outputted from three visible light laser light sources; and Three optical output ports output three visible lights of different wavelengths to the outside.

5. The electro-optical element according to claim 3, wherein: have: 3 optical input ports capable of inputting 3 visible lights of different wavelengths respectively outputted from 3 visible light laser light sources; A light combining unit that combines three visible lights of different wavelengths; and An optical output port outputs the light multiplexed by the optical multiplexing unit to the outside.

6. The electro-optical element according to claim 1, wherein The plurality of optical waveguides for light modulation are N1-1 optical waveguides for light modulation, wherein N1 is an integer greater than or equal to 3, The electro-optical element includes an (N1-1)×2 type optical multiplexing and branching section between the optical branching section and the Mach-Zehnder optical modulator, wherein N1-1 optical waveguides for light modulation are connected on the incident side and two optical waveguides connected to the Mach-Zehnder optical modulator are connected on the output side.

7. The electro-optical element according to claim 1, wherein The plurality of optical waveguides for light modulation are 2N2 optical waveguides for light modulation, wherein N2 is an integer greater than 2, The electro-optical element includes two N2×1 optical branching sections between the optical branching section and the Mach-Zehnder optical modulation section. The two N2×1 optical branching sections are respectively connected to N2 optical waveguides of the 2N2 optical waveguides for light modulation on the incident side and to one optical waveguide connected to the Mach-Zehnder optical modulation section on the output side.

8. A light source module, wherein: It comprises: the electro-optical element described in any one of claims 1, 2, and 6; a visible light laser light source, which outputs visible light input from the light input port; and a laser light intensity control unit, which detects the monitoring light from the monitoring light output port by a light detector and adjusts the laser light intensity emitted from the visible light laser light source corresponding to the detected light intensity.

9. An optical engine, wherein: The light source module according to claim 8 is mounted thereon.

10. An XR glasses, wherein: The light source module according to claim 9 is mounted thereon.

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