Optical devices

Abstract

To form a clear image and video.SOLUTION: An optical device 10 comprises a substrate 90 on which an optical waveguide 12 is formed, a coupler 20, an intensity modulator 30, a plurality of phase modulators 51-58, and a grating coupler 60. The coupler 20 is formed using the optical waveguide 12 and receives light. The intensity modulator 30 is formed using the optical waveguide 12, connected to a subsequent stage of the coupler 20, and performs intensity modulation of the light. The plurality of phase modulators 51-58 are formed using the optical waveguide 12, connected to a subsequent stage of the intensity modulator 30, and performs phase modulation of the light. The grating coupler 60 includes a plurality of radiation elements 61-68 that are formed using the optical waveguide 12, connected to a respective subsequent stage of the plurality of phase modulators 51-58, and emits the light in a predetermined direction using diffraction of the light.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an optical device that outputs light by two-dimensional scanning. [Background technology]

[0002] Patent Document 1 describes an optical deflection device. The optical deflection device described in Patent Document 1 uses a planar optical waveguide circuit. The planar optical waveguide circuit includes a distributor, a plurality of phase modulation units, and a grating coupler.

[0003] The distributor divides the light input from the outside and outputs it to multiple phase modulation units. The multiple phase modulation units modulate the phase of the light input to each of them. The multiple phase modulation units output the modulated light to multiple radiating elements that make up the grating coupler. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7005320 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the configuration described in Patent Document 1, it is not easy to form clear images or videos.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an optical device capable of forming clear images or videos. [Means for solving the problem]

[0007] The optical device of the present invention includes a substrate on which an optical waveguide is formed, a coupler, an intensity modulator, a distributor, multiple phase modulators, and a grating coupler. The coupler is formed using an optical waveguide and accepts light. The intensity modulator is formed using an optical waveguide and connected to a stage subsequent to the coupler to perform intensity modulation of the light. The distributor is formed using an optical waveguide and connected to a stage subsequent to the intensity modulator to distribute the intensity-modulated light. The multiple phase modulators are formed using an optical waveguide and connected to a stage subsequent to the distributor to perform phase modulation of the light. The grating coupler is formed using an optical waveguide and includes multiple radiating elements connected to a stage subsequent to each of the multiple phase modulators to radiate light in a predetermined direction using optical diffraction.

[0008] In this configuration, the intensity modulation and phase modulation of light are realized using an optical waveguide formed on the substrate. This allows the frequency at which the intensity modulation and phase modulation of light are realized to be increased. Therefore, the number of times per unit time that the intensity modulation and phase modulation of light can be switched can be increased. [Effects of the Invention]

[0009] According to the present invention, clear images and videos can be formed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a functional block diagram of the optical device according to the first embodiment. [Figure 2] FIG. 2 is a perspective view of the optical device according to the first embodiment. [Figure 3] FIG. 3 is a plan view of the optical device according to the first embodiment. [Figure 4] FIG. 4(A) is a plan view of the intensity modulator, and FIG. 4(B) is a cross-sectional view of the intensity modulator taken along line A. [Figure 5] 5(A) is a plan view of the phase modulation section, FIG. 5(B) is a B1 cross-sectional view of the phase modulation section, and FIG. 5(C) is a B2 cross-sectional view of the phase modulation section. [Figure 6] FIG. 6 is a perspective view of an optical device that forms a three-color image (video). [Figure 7] FIG. 7 is a functional block diagram of the optical device according to the second embodiment. [Figure 8] FIG. 8 is a functional block diagram of the optical device according to the third embodiment. [Figure 9] FIG. 9 is a perspective view of an optical device according to the fourth embodiment. [Figure 10] FIG. 10 is a functional block diagram of an optical device according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] An optical device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of the optical device according to the first embodiment. FIG. 2 is a perspective view of the optical device according to the first embodiment. Note that in FIG. 2, the thickness of each component of the optical device is omitted as appropriate. FIG. 3 is a plan view of the optical device according to the first embodiment. Note that FIG. 3 is a plan view omitting the upper cladding layer of the optical waveguide. FIG. 4(A) is a plan view of an intensity modulator, and FIG. 4(B) is a cross-sectional view A of the intensity modulator. FIG. 5(A) is a plan view of a phase modulation section, FIG. 5(B) is a cross-sectional view B1 of the phase modulation section, and FIG. 5(C) is a cross-sectional view B2 of the phase modulation section.

[0012] (Functional configuration of the optical device 10) As shown in Fig. 1, the optical device 10 includes a light-emitting element 11 and an optical waveguide 12. The optical waveguide 12 includes a coupler 20, an intensity modulator 30, a splitter 40, a phase modulation section 50, and a grating coupler 60. In other words, the coupler 20, the intensity modulator 30, the splitter 40, the phase modulation section 50, and the grating coupler 60 are formed using the optical waveguide 12. Note that in Fig. 1, the optical device 10 includes the light-emitting element 11. However, the optical device 10 does not necessarily have to include the light-emitting element 11.

[0013] The phase modulation section 50 includes a plurality of phase modulators 51-58 (phase modulator 51, phase modulator 52, phase modulator 53, phase modulator 54, phase modulator 55, phase modulator 56, phase modulator 57, phase modulator 58). The grating coupler 60 includes a plurality of radiating elements 61-68 (radiating element 61, radiating element 62, radiating element 63, radiating element 64, radiating element 65, radiating element 66, radiating element 67, radiating element 68). In the optical device 10, the number of phase modulators and the number of radiating elements are eight. However, the number of phase modulators and the number of radiating elements can be set appropriately depending on the specifications of the optical device 10, etc.

[0014] The coupler 20 has a known configuration. The coupler 20 receives light from the light-emitting element 11 and guides it to the optical waveguide 12. The output light of the coupler 20 is input to the intensity modulator 30. Note that if the optical device 10 does not include the light-emitting element 11, the coupler 20 receives light from outside the optical device 10 and guides it to the optical waveguide 12.

[0015] The intensity modulator 30 is configured by, for example, a Mach-Zehnder modulator (MZ modulator). The intensity modulator 30 adjusts the intensity of the input light from the coupler 20. The intensity modulator 30 outputs the light after the intensity adjustment to the distributor 40.

[0016] The distributor 40 has a known configuration. The distributor 40 distributes the input light from the intensity modulator 30 and outputs it to the multiple phase modulators 51-58. At this time, the distributor 40 distributes the light to be output to the multiple phase modulators 51-58 equally (distribution of the same phase and signal level).

[0017] The multiple phase modulators 51-58 have the configuration described below. The multiple phase modulators 51-58 adjust the phase of the input light from the distributor 40. The multiple phase modulators 51-58 output the phase-modulated light to the multiple radiating elements 61-68. For example, referring to FIG. 1, the phase modulator 51 outputs the phase-modulated light to the radiating element 61, and the phase modulator 52 outputs the phase-modulated light to the radiating element 62. Similarly, the multiple phase modulators 53-58 output the phase-modulated light to the radiating elements 63-68. At this time, the phases set by the multiple phase modulators 51-58 and the differences between the multiple phases set by the multiple phase modulators 51-58 enable two-dimensional scanning of the light finally emitted from the optical device 10.

[0018] Each of the multiple radiating elements 61-68 has a one-dimensional diffraction grating configuration. The multiple radiating elements 61-68 radiate input light from the multiple phase modulators 51-58. For example, the radiating element 61 radiates input light from the phase modulator 51, and the radiating element 62 radiates input light from the phase modulator 52. Similarly, the multiple radiating elements 63-68 radiate input light from the multiple phase modulators 53-58.

[0019] At this time, the phases are adjusted as described above by the plurality of phase modulators 51-58. As a result, the light emitted from the plurality of radiating elements 61-68 becomes light that scans within a two-dimensional plane parallel to the radiating surface of the optical device 10.

[0020] Therefore, the optical device 10 can output two-dimensionally scanned images or videos, and can project these images or videos into a predetermined space, for example.

[0021] Furthermore, with this configuration, the optical device 10 does not need to include an intensity modulator for each of the plurality of radiating elements 61-68. Therefore, the circuit configuration and the structure described below of the optical device 10 are simplified. Furthermore, if an intensity modulator is provided for each of the plurality of radiating elements 61-68, these intensity modulators need to be synchronized, but the optical device 10 does not need to perform such synchronization.

[0022] In this case, the optical device 10 realizes the intensity modulation of light and the phase modulation of the light split into multiple parts by circuit elements (intensity modulator 30 and multiple phase modulators 51-58) formed using the optical waveguide 12. This allows the optical device 10 to perform the intensity modulation of light and the phase modulation of light at high speed and with high precision. In particular, by performing the intensity modulation of light using the optical waveguide 12, the intensity can be adjusted and changed to a predetermined value at high speed and with high precision compared to the light emitting element 11.

[0023] Therefore, the optical device 10 can increase the number of times per unit time that the intensity modulation and phase modulation of light are switched, and as a result, the optical device 10 can form clear images and videos.

[0024] (Structural example of optical device 10) As shown in FIGS. 2, 3, 4(A), 4(B), 5(A), 5(B), and 5(C), the optical device 10 includes a light emitting element 11 and a substrate 90.

[0025] The light emitting element 11 is realized by, for example, a vertical cavity surface emitting laser (VCSEL). The light emitting element 11 is mounted on a substrate 90. More specifically, the light emitting element 11 is mounted on a control electrode 110 formed on the substrate 90. The light emitting element 11 emits light upon receiving a light emission control signal from the control electrode 110. The light emitting element 11 outputs light of a wavelength within the visible light range at a certain level (intensity). At this time, the light emitting element 11 is mounted so that its light emitting surface faces the substrate 90. As a result, the light output from the light emitting element 11 is irradiated onto the substrate 90 (more specifically, onto an entrance window of the coupler 20, which will be described later). Note that the light emitting element 11 does not have to be a vertical cavity surface emitting laser.

[0026] The substrate 90 has a main surface that is a light emitting surface. In the following description, as shown in each drawing, two orthogonal axes constituting the main surface are defined as the x-axis and y-axis, and one axis perpendicular to the main surface is defined as the z-axis.

[0027] As shown in FIGS. 4(B), 5(B), and 5(C), the substrate 90 includes a base material 91, a first cladding layer 92, a light-guiding layer 800, and a second cladding layer 93. The base material 91 is made of, for example, Si. The base material 91 has a main surface parallel to the x-axis direction and the y-axis direction. The first cladding layer 92 is made of, for example, SiO2. The first cladding layer 92 is formed on the main surface of the base material 91.

[0028] The light-guiding layer 800 is made of, for example, LiNbO3. The light-guiding layer 800 is formed on the surface of the first cladding layer 92 opposite to the substrate 91. The light-guiding layer 800 is composed of a base portion and a light-guiding portion that realizes the optical waveguide 12. The light-guiding portion is thicker than the base portion. The thickness of the light-guiding portion (length in the z-axis direction) is a thickness that allows light to propagate as the optical waveguide 12. The thickness of the base portion (length in the z-axis direction) is a thickness that prevents light guided by the optical waveguide 12 from propagating (leaking). In other words, the thicknesses of the light-guiding portion and the base portion are set based on the wavelength of light guided by the optical waveguide 12.

[0029] The second cladding layer 93 is made of, for example, SiO2. The second cladding layer 93 is formed on the surface of the light-guiding layer 800 opposite to the first cladding layer 92. In other words, the second cladding layer 93 and the first cladding layer 92 are formed so as to sandwich the light-guiding layer 800 therebetween.

[0030] In this way, by sandwiching the light-guiding layer 800 between the first cladding layer 92 and the second cladding layer 93 and setting the thickness of the base portion of the light-guiding layer 800 and the thickness and width of the light-guiding portion (the length in the direction in which the light-guiding portion extends and in the direction perpendicular to the thickness direction) to predetermined values, light of a predetermined wavelength propagates through the light-guiding portion, and the substrate 90 functions as an optical waveguide 12.

[0031] It is preferable that the base portion of the light guide layer 800 is as thin as possible, and it is more preferable that the light guide layer 800 has a structure that does not include a base portion, which improves the light confinement effect.

[0032] (Coupler 20 structure) Coupler 20 has an entrance window on the second cladding layer 93 side. The entrance window of coupler 20 faces the light emitting surface of light emitting element 11. Coupler 20 refracts incident light from light emitting element 11, i.e., light propagating in the z-axis direction, into the x-axis direction parallel to the principal surface of substrate 90, depending on the shape of light guiding layer 800. Coupler 20 distributes the light converted into the x-axis direction and outputs it to light guiding section 831 and light guiding section 832.

[0033] (Structure of light guide section 831 and light guide section 832) The light guiding portion 831 and the light guiding portion 832 are formed by the light guiding portion of the above-described light guiding layer 800. The light guiding portion 831 and the light guiding portion 832 connect the coupler 20 and the splitter 40.

[0034] (Structure of intensity modulator 30) 2, 3, 4(A), and 4(B), intensity modulator 30 is disposed adjacent to coupler 20 in the x-axis direction. Intensity modulator 30 includes light-guiding section 831, light-guiding section 832, control electrode 311, control electrode 312, control electrode 320, wiring electrode 331, and wiring electrode 332.

[0035] Light guiding portion 831 and light guiding portion 832 are strip-shaped with a predetermined width in a plan view (when viewed in the z-axis direction). Light guiding portion 831 and light guiding portion 832 are shaped to extend along the x-axis direction and run side by side at a predetermined interval in the y-axis direction.

[0036] Control electrode 311, control electrode 312, and control electrode 320 are rectangular solids in plan view. Control electrode 311, control electrode 312, and control electrode 320 are formed in second cladding layer 93, and abut on the surface of light-guiding layer 800 on the side of second cladding layer 93. Control electrode 311, control electrode 312, and control electrode 320 correspond to the "first control electrode" of the present invention.

[0037] In a plan view, control electrode 320 is disposed between light guiding portion 831 and light guiding portion 832. Control electrode 311 is disposed on the opposite side of control electrode 320, with light guiding portion 831 sandwiched therebetween. Control electrode 312 is disposed on the opposite side of control electrode 320, with light guiding portion 832 sandwiched therebetween. In other words, in a plan view, light guiding portion 831 is disposed at a position sandwiched between control electrode 320 and control electrode 311. Light guiding portion 832 is disposed at a position sandwiched between control electrode 320 and control electrode 312.

[0038] In the configuration of this embodiment, the control electrodes are arranged on both sides of the light guide section extending in the x-axis direction in the y-axis direction. However, it is also possible to arrange the control electrodes on both sides of the light guide section extending in the x-axis direction in the z-axis direction. For example, the base material 91 may have the function of one of the control electrodes, and the other control electrode may be arranged on the opposite side of the one control electrode in the thickness direction of the substrate 90, with the light guide section therebetween.

[0039] The wiring electrodes 331 and 332 are formed on the surface of the second cladding layer 93 opposite to the light-guiding layer 800 side. The wiring electrodes 331 and 332 are linear or strip-shaped electrodes extending in the y-axis direction. The wiring electrode 331 is connected to the control electrodes 311 and 312. The wiring electrode 332 is connected to the control electrode 320.

[0040] Control electrode 320 is an electrode to which a control signal for intensity modulation is applied. Control electrodes 311 and 312 are ground electrodes for the control signal for intensity modulation. The control signal for intensity modulation is applied to control electrode 320 through wiring electrode 332. Control electrodes 311 and 312 are connected to the ground potential through wiring electrode 331.

[0041] When a control signal for intensity modulation is applied to control electrode 320, a phase difference corresponding to the signal level of the control signal for intensity modulation occurs between the light propagating through light-guiding section 831 and the light propagating through light-guiding section 832. Therefore, when the light propagating through light-guiding section 831 and the light propagating through light-guiding section 832 are multiplexed (by distributor 40, described below), interference corresponding to the phase difference occurs. This makes it possible to adjust the level (intensity) of the light after multiplexing. In other words, intensity modulator 30 realizes a Mach-Zehnder modulator (MZ modulator) with a planar structure.

[0042] By using the intensity modulator 30 having such a configuration, it is possible to perform intensity modulation at a higher speed than directly modulating the intensity of the light emitting element 11. In other words, the intensity modulator 30 can switch the intensity at a higher speed than the light emitting element 11. More specifically, the modulation speed of the light emitting element 11 is limited by the relaxation oscillation frequency, which is the interaction between carriers and photons. However, by providing the configuration of the intensity modulator 30, it is possible to perform modulation (switching or changing the intensity) at a higher frequency than the relaxation oscillation frequency of the light emitting element 11.

[0043] (Structure of distributor 40) 2 and 3, the distributor 40 is disposed adjacent to the intensity modulator 30 in the x-axis direction. In this case, the distributor 40 is disposed on the opposite side of the coupler 20 with respect to the intensity modulator 30. The distributor 40 has a three-dimensional shape having a predetermined area in a plan view. More specifically, the distributor 40 is formed by making a part of the light-guiding layer 800 thicker than the base part, similar to the light-guiding section.

[0044] The distributor 40 is connected to the light guiding section 831 and the light guiding section 832. The light guiding section 831 and the light guiding section 832 are connected to the intensity modulator 30 side of the distributor 40.

[0045] The distributor 40 is connected to a plurality of light guiding sections 851-858 (light guiding section 851, light guiding section 852, light guiding section 853, light guiding section 854, light guiding section 855, light guiding section 856, light guiding section 857, light guiding section 858). The plurality of light guiding sections 851-858 are connected to the side of the distributor 40 opposite to the intensity modulator 30 side.

[0046] By appropriately setting the three-dimensional shape of distributor 40, the connection positions of light guiding section 831 and light guiding section 832, and the connection positions of multiple light guiding sections 851-858, distributor 40 can combine the light from light guiding section 831 and the light from light guiding section 832, and distribute and output the combined light to multiple light guiding sections 851-858. In this case, distributor 40 distributes the light output to multiple light guiding sections 851-858 so that the intensities and phases of the light are the same.

[0047] The distributor 40 may have a structure in which one input is divided into the number of final outputs in one stage (for example, 8 outputs in this embodiment), or a structure in which the number of final outputs is divided into multiple stages (for example, for 8 outputs, a tournament-type distributor with 2 divisions x 3 stages) may be used. In other words, the distributor 40 may have any structure as long as it can divide the multiple light beams that are finally output so that they have the same intensity and phase.

[0048] (Structure of multiple light guides 851-858) The plurality of light guiding sections 851-858 are formed by the light guiding sections of the above-described light guiding layer 800, similar to the light guiding sections 831 and 832. The plurality of light guiding sections 851-858 are connected from the distributor 40 to the grating coupler 60.

[0049] (Structure of phase modulation section 50) As shown in FIGS. 2, 3, 5(A), 5(B), and 5(C), the phase modulation section 50 is disposed adjacent to the distributor 40 in the x-axis direction. The phase modulation section 50 includes a plurality of light-guiding sections 851-858, a plurality of control electrodes 511-514 (control electrode 511, control electrode 512, control electrode 513, and control electrode 514), a plurality of control electrodes 521-528 (control electrode 521, control electrode 522, control electrode 523, control electrode 524, control electrode 525, control electrode 526, control electrode 527, and control electrode 528), a plurality of wiring electrodes 531-538 (wiring electrode 531, wiring electrode 532, wiring electrode 533, wiring electrode 534, wiring electrode 535, wiring electrode 536, wiring electrode 537, and wiring electrode 538), and wiring electrode 540.

[0050] The light guiding sections 851-858 are each strip-shaped with a predetermined width in a plan view (when viewed in the z-axis direction). The light guiding sections 851-858 are shaped to extend along the x-axis direction, are arranged in the y-axis direction, and run parallel to each other at predetermined intervals.

[0051] The plurality of control electrodes 511-514 and the plurality of control electrodes 521-528 are rectangular solids in plan view. The control electrodes 311, 312, and 320 are formed in the second cladding layer 93 and abut on the surface of the light-guiding layer 800 on the second cladding layer 93 side. The length of the plurality of control electrodes 511-514 in the x-axis direction is greater than the length of the plurality of control electrodes 521-528 in the x-axis direction. For example, the length of the plurality of control electrodes 511-514 is approximately the same as the overall length of the phase modulation section 50 in the x-axis direction. The plurality of control electrodes 511-514 and the plurality of control electrodes 521-528 correspond to the "second control electrodes" of the present invention.

[0052] In a plan view, control electrode 511 is disposed between light guiding portion 851 and light guiding portion 852. Control electrode 512 is disposed between light guiding portion 853 and light guiding portion 854. Control electrode 513 is disposed between light guiding portion 855 and light guiding portion 856. Control electrode 514 is disposed between light guiding portion 857 and light guiding portion 858.

[0053] In a plan view, control electrode 521 is disposed on the opposite side of control electrode 511 with light guiding portion 851 interposed therebetween. Control electrodes 522 and 523 are disposed between light guiding portion 852 and light guiding portion 853. In this case, control electrode 522 is close to light guiding portion 852 and away from light guiding portion 853, and control electrode 523 is close to light guiding portion 853 and away from light guiding portion 852. Control electrodes 524 and 525 are disposed between light guiding portion 854 and light guiding portion 855. In this case, control electrode 524 is close to light guiding portion 854 and away from light guiding portion 855, and control electrode 525 is close to light guiding portion 855 and away from light guiding portion 854. Control electrodes 526 and 527 are disposed between light guiding portion 856 and light guiding portion 857. In this case, control electrode 526 is close to light-guiding portion 856 and away from light-guiding portion 857, and control electrode 527 is close to light-guiding portion 857 and away from light-guiding portion 856. Control electrode 528 is arranged on the opposite side of control electrode 514 with light-guiding portion 858 in between.

[0054] In other words, in a plan view, light guiding portion 851 is disposed at a position sandwiched between control electrode 511 and control electrode 521. Light guiding portion 852 is disposed at a position sandwiched between control electrode 511 and control electrode 522. Light guiding portion 853 is disposed at a position sandwiched between control electrode 512 and control electrode 523. Light guiding portion 854 is disposed at a position sandwiched between control electrode 512 and control electrode 524. Light guiding portion 855 is disposed at a position sandwiched between control electrode 513 and control electrode 525. Light guiding portion 856 is disposed at a position sandwiched between control electrode 513 and control electrode 526. Light guiding portion 857 is disposed at a position sandwiched between control electrode 514 and control electrode 527. Light guiding portion 858 is disposed at a position sandwiched between control electrode 514 and control electrode 528. In this way, the phase modulation section 50 is realized by a coplanar structure.

[0055] The wiring electrodes 531-538 and the wiring electrode 540 are formed on the surface of the second cladding layer 93 opposite to the light guide layer 800. The wiring electrodes 531-538 and the wiring electrode 540 are linear or strip-shaped electrodes extending in the y-axis direction.

[0056] The plurality of wiring electrodes 531-538 are connected to the plurality of control electrodes 521-528, respectively. For example, wiring electrode 531 is connected to control electrode 521, and wiring electrode 532 is connected to control electrode 522. The plurality of wiring electrodes 533-538 are also connected to the plurality of control electrodes 523-528, similar to wiring electrodes 531 and 532. Wiring electrode 540 is connected to the plurality of control electrodes 511-514.

[0057] The plurality of control electrodes 511-514 are electrodes for grounding the control signals for phase modulation.

[0058] A control signal for phase modulation is applied to the plurality of control electrodes 521-528. More specifically, a control signal for phase-modulating light propagating through light-guiding portion 851 is applied to control electrode 521, and a control signal for phase-modulating light propagating through light-guiding portion 852 is applied to control electrode 522. Similarly, control signals for individually phase-modulating the phases of light propagating through the plurality of light-guiding portions 853-858 are applied to the plurality of control electrodes 523-528, respectively.

[0059] By adjusting the control signals applied to the plurality of control electrodes 521-528, phase modulation unit 50 can individually set the phases of the light propagating through the plurality of light-guiding units 851-858. This allows phase modulation unit 50 to adjust the phase of the light propagating through the plurality of light-guiding units 851-858 relative to the propagation direction, and adjust the phase difference between the plurality of light propagating through the plurality of light-guiding units 851-858.

[0060] By using the phase modulation section 50 configured in this way, high-speed phase modulation is possible.

[0061] (Structure of Grating Coupler 60) As shown in Figures 2 and 3, the grating coupler 60 is disposed adjacent to the phase modulation unit 50 in the x-axis direction. The grating coupler 60 is formed by a plurality of light-guiding units 861-868. The plurality of light-guiding units 861-868 have a shape that extends in the x-axis direction. The plurality of light-guiding units 861-868 have the same structure as the plurality of light-guiding units 851-858, except for the portions that emit light.

[0062] The plurality of light guiding portions 861-868 are connected to the plurality of light guiding portions 851-858. More specifically, the light guiding portion 861 is connected to the light guiding portion 851, and the light guiding portion 862 is connected to the light guiding portion 852. The plurality of light guiding portions 863-868 are also connected to the plurality of light guiding portions 853-858, similar to the light guiding portions 861 and 862.

[0063] The plurality of light-guiding sections 861-868 have uneven portions at their tip portions (end portions opposite to the side connected to the plurality of light-guiding sections 851-858). The uneven portions are formed on the surfaces of the plurality of light-guiding sections 861-868 facing the second cladding layer 93. The uneven portions are formed at a predetermined period along the extension direction of the plurality of light-guiding sections 861-868 (for example, the x-axis direction in the case of FIGS. 2 and 3). This period and the shape of the uneven portions are set depending on the wavelength and target radiation area of ​​the light emitted by the optical device 10, i.e., the light propagating through the optical waveguide 12. The uneven portions formed on the plurality of light-guiding sections 861-868 realize the plurality of radiating elements 61-68.

[0064] With the above-described structure, the optical device 10 can be realized using the substrate 90. That is, the optical device 10 can be realized with a simple structure.

[0065] Therefore, the optical device 10 can form clear images and videos while employing a simple structure.

[0066] (When forming a three-color image (video)) The above-described configuration shows the case where a monochromatic image (video) is formed. This configuration can also be used to form a polychromatic image (video). FIG. 6 is a perspective view of an optical device that forms a three-color image (video). As with FIG. 2, the thickness of each component of the optical device is omitted as appropriate in FIG. 6.

[0067] 6, the optical device 10t includes optical devices 10t1, 10t2, and 10t3. The optical devices 10t1, 10t2, and 10t3 have the same configuration as the optical device 10, but each propagates and emits light with a different wavelength.

[0068] The optical waveguide of optical device 10t1 is formed to be suitable for the propagation of a first color. Optical device 10t1 performs intensity modulation and phase modulation of the first color light to form an image (video) of the first color. The optical waveguide of optical device 10t2 is formed to be suitable for the propagation of a second color. Optical device 10t2 performs intensity modulation and phase modulation of the second color light to form an image (video) of the second color. The optical waveguide of optical device 10t3 is formed to be suitable for the propagation of a third color. Optical device 10t3 performs intensity modulation and phase modulation of the third color light to form an image (video) of the third color.

[0069] The optical device 10t1, the optical device 10t2, and the optical device 10t3 each emit light so that the areas forming the images (video) overlap. This allows the optical device 10t to form a three-color image (video). For example, the first color is red, the second color is green, and the third color is blue. This allows the optical device 10t to form a color image (color video).

[0070] The optical devices 10t1, 10t2, and 10t3 are formed on a single substrate 90t. The substrate 90t has the same layer structure as the substrate 90. The optical devices 10t1, 10t2, and 10t3 are arranged in the y-axis direction of the substrate 90t, which is perpendicular to the x-axis direction (the main propagation direction of light in each device).

[0071] As a result, the optical device 10t can form clear multi-color (eg, color) images or videos with a low profile and simple configuration.

[0072] The arrangement pattern of the optical devices 10t1, 10t2, and 10t3 is not limited to the example shown in FIG. 6, and other arrangement patterns are also possible.

[0073] [Second embodiment] An optical device according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 7 is a functional block diagram of the optical device according to the second embodiment. Note that Fig. 7 shows an example of an optical device that forms an image (video) in three colors (RGB), but the configuration of this embodiment can be applied to an optical device that forms a multi-color image (video).

[0074] 7, an optical device 10A according to the second embodiment differs from the optical device 10 according to the first embodiment in that it includes an optical waveguide 12A. The optical waveguide 12A differs from the optical waveguide 12 according to the first embodiment in that it includes a light emitting element 11R, a light emitting element 11G, a light emitting element 11B, a coupler 20R, a coupler 20G, a coupler 20B, and a multiplexer 29. Other configurations of the optical device 10A and the optical waveguide 12A are similar to those of the optical device 10 and the optical waveguide 12, and a description of similar parts will be omitted.

[0075] The coupler 20R, coupler 20G, and coupler 20B have the same configuration as the coupler 20 according to the first embodiment. The coupler 20R is for red light, the coupler 20G is for green light, and the coupler 20B is for blue light. The couplers 20R, 20G, and 20B are formed using an optical waveguide 12A. The optical waveguide 12A has the same configuration as the optical waveguide 12 according to the first embodiment.

[0076] The multiplexer 29 is formed using the optical waveguide 12A. The multiplexer 29 is disposed between the coupler 20R, the coupler 20G, and the coupler 20B and the intensity modulator 30. The multiplexer 29 is connected to the coupler 20R, the coupler 20G, and the coupler 20B, and is also connected to the intensity modulator 30.

[0077] Coupler 20R guides the red light output from light-emitting element 11R to optical waveguide 12A and outputs it to multiplexer 29. Coupler 20G guides the green light output from light-emitting element 11G to optical waveguide 12A and outputs it to multiplexer 29. Coupler 20B guides the blue light output from light-emitting element 11B to optical waveguide 12A and outputs it to multiplexer 29.

[0078] The multiplexer 29 multiplexes the red light from the coupler 20R, the green light from the coupler 20G, and the blue light from the coupler 20B, and outputs the multiplexed light to the intensity modulator 30.

[0079] With this configuration, the optical device 10A can form clear images or videos of multi-color light, such as color, with a low profile and simple configuration. Furthermore, with this configuration, even when forming images or videos of multi-color light, clear images or videos of multi-color light, such as color, can be formed simply by forming a plurality of couplers and multiplexers corresponding to the number of colors on the substrate. Therefore, the optical device 10A can have an even simpler configuration and a smaller area in plan view.

[0080] [Third embodiment] An optical device according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 8 is a functional block diagram of the optical device according to the third embodiment. Note that Fig. 8 shows an example of an optical device that forms an image (video) in three colors (RGB), but the configuration of this embodiment can be applied to an optical device that forms a multi-color image (video).

[0081] 8, the optical device 10B according to the third embodiment differs from the optical device 10A according to the second embodiment in that it includes an optical waveguide 12B. The optical waveguide 12B differs from the optical waveguide 12A according to the second embodiment in that it includes an intensity modulator 30R, an intensity modulator 30G, and an intensity modulator 30B, and in the connection relationship with the multiplexer 29. Other configurations of the optical device 10B and the optical waveguide 12B are similar to those of the optical device 10A and the optical waveguide 12A, and a description of similar parts will be omitted.

[0082] The intensity modulators 30R, 30G, and 30B have the same configuration as the intensity modulator 30 according to the first and second embodiments. The intensity modulators 30R, 30G, and 30B are formed using an optical waveguide 12B. The optical waveguide 12B has the same configuration as the optical waveguides 12 and 12A according to the first and second embodiments.

[0083] The intensity modulator 30R is disposed adjacent to the coupler 20R and connects to the coupler 20R. The intensity modulator 30G is disposed adjacent to the coupler 20G and connects to the coupler 20G. The intensity modulator 30B is disposed adjacent to the coupler 20B and connects to the coupler 20B.

[0084] The multiplexer 29 is disposed between the intensity modulator 30R, the intensity modulator 30G, and the intensity modulator 30B and the distributor 40. The multiplexer 29 is connected to the intensity modulator 30R, the intensity modulator 30G, and the intensity modulator 30B, and is also connected to the distributor 40.

[0085] The intensity modulator 30R modulates the intensity of the red light output from the coupler 20R and outputs the modulated light to the combiner 29. The intensity modulator 30G modulates the intensity of the green light output from the coupler 20G and outputs the modulated light to the combiner 29. The intensity modulator 30B modulates the intensity of the blue light output from the coupler 20B and outputs the modulated light to the combiner 29. At this time, the intensity modulators 30R, 30G, and 30B perform intensity modulation in synchronization.

[0086] The multiplexer 29 multiplexes the red light output from the intensity modulator 30R, the green light output from the intensity modulator 30G, and the blue light output from the intensity modulator 30B, and outputs the multiplexed light to the distributor 40.

[0087] This configuration allows the optical device 10B to form clear images or videos using multi-color light, such as color, with a low profile and simple configuration. This configuration also allows the optical device 10B to perform intensity modulation for each color. Therefore, the optical device 10B can achieve a wider variety of color tones and form images or videos with higher resolution and greater gradation.

[0088] [Fourth embodiment] An optical device according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 9 is a perspective view of the optical device according to the fourth embodiment. Note that in Fig. 9 as well, the thickness of each component of the optical device is omitted as appropriate, as in Figs. 2 and 6.

[0089] 9, the optical device 10C differs from the optical device 10t according to the first embodiment in that it includes optical devices 10C1, 10C2, and 10C3. The other configuration of the optical device 10C is the same as that of the optical device 10t, and a description of similar parts will be omitted.

[0090] Optical device 10C1, optical device 10C2, and optical device 10C3 have the same configuration as optical device 10t1, optical device 10t2, and optical device 10t3, respectively. Optical device 10C1 is formed on substrate 90C1, optical device 10C2 is formed on substrate 90C2, and optical device 10C3 is formed on substrate 90C3. Substrate 90C1, substrate 90C2, and substrate 90C3 have the same configuration as substrate 90 according to the first embodiment.

[0091] Substrate 90C1, substrate 90C2, and substrate 90C3 are arranged in order in the thickness direction (z-axis direction) of these substrates. In other words, substrate 90C1, substrate 90C2, and substrate 90C3 are stacked in order in the z-axis direction. At this time, optical device 10C1, optical device 10C2, and optical device 10C3 are stacked so that the areas of the images (videos) formed by each optical device overlap.

[0092] This allows the optical device 10C to form a three-color image (video). Therefore, the optical device 10C can form a clear multi-color (for example, color) image or video with a small area in a plan view and a simple configuration.

[0093] [Fifth embodiment] An optical device according to a fifth embodiment of the present invention will be described with reference to the drawing. Fig. 10 is a functional block diagram of the optical device according to the fifth embodiment.

[0094] 10, the optical device 10D according to the fifth embodiment differs from the optical device 10 according to the first embodiment in that it includes a modulation control unit 70. Other configurations of the optical device 10D are the same as those of the optical device 10, and a description of similar parts will be omitted.

[0095] The modulation control unit 70 is formed by, for example, electronic components such as ICs, etc. The modulation control unit 70 may also be an arithmetic processing unit such as a PC.

[0096] When the modulation control unit 70 is an electronic component, the modulation control unit 70 is mounted on a substrate 90 that realizes the optical device 10. Note that the modulation control unit 70 may also be mounted on another circuit board on which the substrate 90 is mounted.

[0097] The modulation control unit 70 outputs modulation control signals to the intensity modulator 30 and the multiple phase modulators 51-58 of the phase modulation unit 50. The modulation control signals are signals that indicate the timing of intensity modulation, the modulation amount of intensity modulation, the timing of phase modulation, and the modulation amount of phase modulation. In other words, the modulation control signals include a control signal for intensity modulation and a control signal for phase modulation.

[0098] The modulation control unit 70 uses the modulation control signal to set the timing of intensity modulation and the timing of phase modulation, thereby achieving synchronization of modulation between the intensity modulator 30 and the multiple phase modulators 51-58 of the phase modulation unit 50.

[0099] This configuration allows the optical device 10D to more reliably achieve synchronization between intensity modulation and phase modulation, thereby enabling the optical device 10D to form clearer images and videos.

[0100] In the above-described embodiments, a vertical cavity surface emitting laser is used as the light emitting element. However, the light emitting element may be configured by combining a laser element (corresponding to the "base light emitting element" of the present invention) with a nonlinear optical crystal. In this case, the light emitting element causes light from the laser element to enter the nonlinear optical crystal and separates the emitted light. This allows the light emitting element to output the second harmonic (a wave with twice the frequency) of the light irradiated by the laser element. By using such a configuration, the light emitting element can generate light with a short wavelength and low energy.

[0101] In addition, in each of the above-described embodiments, an image or video is formed using light emitted from an optical device. However, a configuration may be provided in which the image or video is focused at a predetermined position. For example, a concave reflecting mirror may be provided to reflect light emitted from the optical device so that the image is focused on a person's retina. In this case, for example, the optical device and the concave reflecting mirror may be formed as a wearable device such as glasses.

[0102] In the above description, the light guide layer 800 has a base portion with a predetermined thickness. However, in any part constituting the optical device described above, it is preferable that the base portion of the light guide layer 800 is as thin as possible, and it is more preferable that the light guide layer 800 does not have a base portion.

[0103] The configurations of the above-described embodiments can be combined as appropriate, and effects according to each combination can be achieved. [Explanation of symbols]

[0104] 10, 10A, 10B, 10C, 10C1, 10C2, 10C3, 10D, 10t, 10t1, 10t2, 10t3: Optical device 11, 11R, 11G, 11B: Light-emitting elements 12, 12A, 12B: Optical waveguide 20, 20R, 20G, 20B: Coupler 29: Multiplexer 30, 30R, 30G, 30B: Intensity modulator 40:Distributor 50: Phase modulation section 51-58: Phase modulator 60: Grating coupler 61-68: Radiating element 70: Modulation control section 90, 90C1, 90C2, 90C3, 90t: PCB 91: Base material 92: First cladding layer 93: Second cladding layer 311, 312, 320: Control electrodes 331, 332: Wiring electrode 511-514, 521-528: Control electrodes 531-538, 540: Wiring electrode 800: Light guide layer 831, 832, 851-858: Light guide section

Claims

1. a substrate on which an optical waveguide is formed; a coupler formed using the optical waveguide and receiving light; an intensity modulator formed using the optical waveguide and connected to a subsequent stage of the coupler, for modulating the intensity of light; a distributor formed using the optical waveguide, connected to a subsequent stage of the intensity modulator, and distributing intensity-modulated light; a plurality of phase modulators formed using the optical waveguide, connected to a downstream stage of the distributor, and performing phase modulation of light; a grating coupler formed using the optical waveguide, connected to a subsequent stage of each of the plurality of phase modulators, and including a plurality of radiating elements that radiate light in a predetermined direction using diffraction of light; Equipped with An optical device, wherein the phase modulator and the radiating element are directly connected using the optical waveguide.

2. the number of the intensity modulators is less than the number of the phase modulators; 10. The optical device of claim 1.

3. The optical waveguides are individually formed for each of the three primary colors of light, The optical waveguides of the respective colors are arranged side by side in a direction parallel to the main surface of the substrate.

3. The optical device according to claim 1.

4. The optical waveguides are individually formed for each of the three primary colors of light, The optical waveguides for each color are formed on separate substrates, the plurality of substrates forming the optical waveguides of the respective colors are arranged side by side in a direction perpendicular to the main surfaces of the plurality of substrates; 3. The optical device according to claim 1.

5. The couplers include a first coupler, a second coupler, and a third coupler formed for each of the three primary colors of light; a multiplexer formed using the optical waveguide, connected between the first coupler, the second coupler, and the third coupler and the intensity modulator, and configured to multiplex output light from the first coupler, the second coupler, and the third coupler; Equipped with 3. The optical device according to claim 1.

6. The couplers include a first coupler, a second coupler, and a third coupler formed for each of the three primary colors of light; a first intensity modulator, a second intensity modulator, and a third intensity modulator that constitute the intensity modulator and are each formed individually using the optical waveguide; a multiplexer formed using the optical waveguide; Equipped with the first intensity modulator is connected to a subsequent stage of the first coupler; the second intensity modulator is connected to a subsequent stage of the second coupler; the third intensity modulator is connected to a subsequent stage of the third coupler; the combiner is connected between the first intensity modulator, the second intensity modulator, and the third intensity modulator and the distributor, and combines the output light of the first intensity modulator, the output light of the second intensity modulator, and the output light of the third intensity modulator, and outputs the combined light to the distributor; 3. The optical device according to claim 1.

7. a modulation control unit that supplies a control signal for intensity modulation to the intensity modulator and a control signal for phase modulation to the phase modulator while synchronizing the intensity modulator and the phase modulator, 7. The optical device according to claim 1.

8. The intensity modulator comprises: the optical waveguide; a first control electrode sandwiching the optical waveguide in a direction parallel to a major surface of the substrate; Equipped with 8. The optical device according to claim 1.

9. The phase modulator comprises: the optical waveguide; second control electrodes sandwiching the optical waveguide in a direction parallel to the main surface of the substrate; Equipped with 9. The optical device according to claim 1.

10. a light emitting element that causes the light to be incident on the coupler; 10. The optical device according to claim 1.

11. The light-emitting element is a base light-emitting element; a nonlinear optical crystal on which light output from the base light emitting element is incident; The optical device of claim 10, comprising:

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