Optical phased array chip, control method, and optical waveguide phased array system

Abstract

The present invention provides an optical phased array chip including N stages of spectroscopic units, where N is a positive integer, and the spectroscopic units include optical waveguide branches, wherein a first end of a first thermal-optical phase shifter is connected to a predetermined voltage and a first end of a second thermal-optical phase shifter is grounded, and in the same optical waveguide branch, the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter are connected to the same voltage, the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the same optical waveguide branch are the same, and when N is greater than 1, the number of optical waveguide branches in the subsequent spectroscopic unit is twice the number of optical waveguide branches in the previous spectroscopic unit. In the optical waveguide phased array chip of the present invention, the phase change of the optical waveguide and the required control voltage change are linearly related, and the number of required pins is reduced, simplifying phased array control. The present invention further provides a method for controlling an optical phased array chip and an optical waveguide phased array system.

Description

[Technical Field]

[0001] The present invention relates to the technical field of optical phased arrays, and in particular to an optical phased array chip, a control method and an optical waveguide phased array system. [Background technology]

[0002] Optical phased arrays (OPAs) are widely applied in many fields, including laser radar, imaging, free-space optical communications, and laser ranging. Optical phased arrays can be realized using liquid crystals, microelectromechanical systems (MEMS) devices, optical waveguides, etc. Optical waveguide phased arrays have attracted widespread attention and applications in recent years due to their fast response speed, low control voltage, large scanning angle, and ease of large-scale integration.

[0003] Optical phase shifters are the core components in optical phased arrays, and they primarily achieve phase change through the electro-optic or thermo-optic effect of materials. While electro-optic phase shifters change the optical phase, they often introduce optical absorption and alter the light intensity, which is undesirable in optical phased array applications. In contrast, the working principle of thermo-optic phase shifters is to place a heater (i.e., a resistor) around the waveguide, and heat it to change the refractive index of the waveguide, thereby further changing the phase of the light wave. This does not affect the light intensity, making them more widely applicable.

[0004] FIG. 1 is a schematic diagram of a prior art optical waveguide phased array chip. Referring to FIG. 1, the optical waveguide phased array chip shows a splitter 11, optical waveguides 12, and a thermal-optical phase shifter 13, but does not show other components such as a light source and a transmitter. The cascaded splitter and phase shifter are two separate components. In an optical waveguide phased array chip, light emitted from a light source is split into nine beams through three cascaded 1x2 splitters within the chip. A thermal-optical phase shifter 13 is integrated on each of the eight optical waveguides 12 in the final stage. Applying a voltage or current to each of the eight thermal-optical phase shifters 13, depending on whether the control current is voltage-driven or current-driven, provides a fixed phase difference dφ to the light output by the eight optical waveguides, which then interferes with the eight wave sources at different positions, ultimately directing the output beam in a specific direction. By controlling the phase difference back and forth, the effect of beam scanning can be achieved.

[0005] Referring to the optical waveguide phased array chip in FIG. 1, to generate a fixed phase difference dφ, different voltages or currents must be applied to the resistors of the eight thermo-optical phase shifters 13. Referring to the voltages V1 to V8 shown in FIG. 1, the phases of the output light from the eight optical waveguides 12 are sequentially 0, dφ, 2dφ, magic sound φ, 4dφ, 5dφ, 6dφ, and 7dφ. The phase change of the optical waveguide is proportional to the thermal power P, i.e., proportional to the square of the voltage V or current I, and P=V 2 / R,P=I 2 ×R, the phase has a nonlinear relationship with the applied voltage or current, making the control of the optical waveguide phased array complex. Furthermore, because the required phase generated in each optical waveguide is different, the required applied voltage or current is different, further complicating the control. Furthermore, the optical waveguide phased array chip described above, which includes eight output optical channels, requires nine electrical pins, i.e., N channels require N+1 electrical pins, which is a large number and complicates the control of the optical waveguide phased array.

[0006] Therefore, it is necessary to provide a new optical phased array chip, a control method and an optical waveguide phased array system to solve the above problems existing in the prior art. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an optical phased array chip, a control method, and an optical waveguide phased array system that can achieve a linear relationship between the phase difference change between each optical waveguide in the optical phased array and the voltage change, thereby simplifying the control method of the optical phased array. [Means for solving the problem]

[0008] In order to achieve the above object, the optical phased array chip of the present invention includes N-stage spectroscopic units, where N is a positive integer, the spectroscopic units include one or more optical waveguide branches, each optical waveguide branch in each stage spectroscopic unit includes a spectrometer, a first optical waveguide, a second optical waveguide, a first thermal-optical phase shifter, and a second thermal-optical phase shifter, the first thermal-optical phase shifter is integrated on the first optical waveguide, the second thermal-optical phase shifter is integrated on the second optical waveguide, a first output port of the spectrometer is connected to a first end of the first optical waveguide, and a second output port of the spectrometer is connected to a first end of the second optical waveguide, and N is a positive integer greater than 1. When the resistance of the first thermal-optical phase shifter and the second thermal-optical phase shifter in each of the optical waveguide branches in the spectroscopic section at the previous stage is larger than the resistance of the second thermal-optical phase shifter, the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in each of the optical waveguide branches in the spectroscopic section at the previous stage are respectively connected to the input ports of the two spectrometers in the spectroscopic section at the subsequent stage, the first end of the first thermal-optical phase shifter in each of the optical waveguide branches is connected to a predetermined voltage, the first end of the second thermal-optical phase shifter is grounded, the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in the same optical waveguide branch are connected to the same voltage, and the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the same optical waveguide branch are the same.

[0009] The beneficial effect of the optical waveguide phased array chip of the present invention is that the change in phase difference between each optical waveguide in the optical phased array and the required voltage change are linearly related, which makes it easier to control the optical waveguide phased array chip and reduces the number of required pins, thereby simplifying the control of the phased array.

[0010] Optionally, the voltage terminals connected to the second end of the first thermo-optic phase shifter and the second end of the second thermo-optic phase shifter in each of the optical waveguide branches are different.

[0011] Optionally, in any one of the spectroscopic units, the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter are connected to the same voltage.

[0012] Optionally, the second ends of all of the first thermo-optical phase shifters and the second ends of all of the second thermo-optical phase shifters are connected to the same voltage.

[0013] Optionally, the resistances of all the first thermo-optical phase shifters and all the second thermo-optical phase shifters are the same.

[0014] Optionally, when the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the spectroscopic section of the same stage are the same, and N is greater than 1, the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the spectroscopic section of the subsequent stage are both twice the resistance of the first thermal-optical phase shifter in the spectroscopic section of the previous stage.

[0015] Optionally, the voltage connected to the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter in the same optical waveguide branch is the sum of a DC voltage and a variable voltage, wherein the DC voltage is used to set an initial phase and the variable voltage is used to generate a phase change to further control beam scanning of a phased array.

[0016] The present invention further provides a control method for the optical phased array chip, which controls the phase differences of the output waveguides between the adjacent first and second waveguides in the same spectroscopic unit to be the same, and when N is greater than 1, the phase difference of the output waveguides between the adjacent first and second waveguides in the spectroscopic unit of the previous stage is twice the phase difference of the output waveguides between the adjacent first and second waveguides in the spectroscopic unit of the subsequent stage.

[0017] The beneficial effect of the method for controlling an optical waveguide phased array chip of the present invention is that the change in the phase difference between each optical waveguide in the optical phased array and the required change in control voltage can be controlled to have a linear relationship, which makes it easier to control the optical waveguide phased array chip, reduces the number of required pins, and simplifies the control of the phased array.

[0018] selectively, by adjusting a voltage connected to a second end of the first thermo-optic phase shifter and a second end of the second thermo-optic phase shifter in the spectroscopic unit of the same stage, a phase difference of an output waveguide between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the same stage is controlled, wherein adjusting the voltage connected to the second end of the first thermo-optic phase shifter and the second end of the second thermo-optic phase shifter in the spectroscopic unit of the same stage as described above includes: Dividing the square of the preset voltage by the resistance of the first thermo-optic phase shifter in the spectroscopic unit of the same stage to be adjusted as first data; Dividing a phase difference of an output waveguide between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the same stage by a quotient of a first coefficient as second data; subtracting the difference of the second data from the first data as third data; Dividing the resistance of the first thermo-optic phase shifter in the spectroscopic unit of the same stage to be adjusted by twice the preset voltage as fourth data; The voltage connected to the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in the spectroscopic unit of the same stage is the product of the fourth data and the third data.

[0019] The present invention further provides an optical waveguide phased array system, which includes a control circuit, a sequentially connected light source, the optical phased array chip, an emitter, and an optical assembly system, wherein the control circuit is respectively connected to the light source and the optical phased array chip, and is used to control the light emission and optical phase. [Effects of the Invention]

[0020] The beneficial effect of the optical phased array system of the present invention is that the change in the phase difference between each waveguide of the optical phased array chip in the optical phased array system has a linear relationship with the change in the control voltage, which simplifies the control method of the phased array and reduces the number of required electrical pins. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram of a prior art optical waveguide phased array chip. [Figure 2] FIG. 1 is a schematic diagram of an optical waveguide phased array of an optical waveguide phased array chip in accordance with some embodiments of the present invention. [Figure 3] 1 is a schematic diagram of an optical waveguide phased array chip and control voltage connection relationship in some embodiments of the present invention. [Figure 4] 1A and 1B are schematic diagrams of optical waveguide phased array chips according to some other embodiments of the present invention. [Figure 5] FIG. 10 is a schematic diagram of an optical waveguide phased array chip according to some other embodiments of the present invention. [Figure 6] FIG. 1 is a schematic diagram of an optical waveguide phased array system according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] In order to clarify the objectives, technical solutions, and advantages of the present invention, the following clearly and completely describes the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. It is clear that the described embodiments are only a part of the embodiments of the present invention, and do not include all the embodiments. All other embodiments obtained based on the embodiments of the present invention without the need for creative efforts by those skilled in the art are within the scope of protection of the present invention. Unless otherwise defined, technical or scientific terms used herein have the ordinary meanings understood by those skilled in the art. As used in this specification, similar words such as "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but do not exclude other elements or objects.

[0023] In view of the problems existing in the prior art, an embodiment of the present invention provides an optical phased array chip including an N-stage splitting unit, where N is a positive integer, and the splitting unit includes one or more optical waveguide branches, and each optical waveguide branch in each stage splitting unit includes a splitter, a first optical waveguide, a second optical waveguide, a first thermal-optical phase shifter, and a second thermal-optical phase shifter, the first thermal-optical phase shifter being integrated on the first optical waveguide, and the second thermal-optical phase shifter being integrated on the second optical waveguide, a first output port of the splitter being connected to a first end of the first optical waveguide, and a second output port of the splitter being connected to a first end of the second optical waveguide, When N is greater than 1, the second end of the first thermal phase shifter and the second end of the second thermal phase shifter of each of the optical waveguide branches in the preceding spectroscopic section are respectively connected to the input ports of the two spectrometers in the succeeding spectroscopic section, the first end of the first thermal-optical phase shifter in each of the optical waveguide branches is connected to a predetermined voltage, the first end of the second thermal-optical phase shifter is grounded, the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in the same optical waveguide branch are connected to the same voltage, and the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the same optical waveguide branch are the same.

[0024] In some embodiments, the voltage terminals connected to the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter in each of the optical waveguide branches are different.

[0025] In some embodiments, in any one of the spectroscopic units, the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter are connected to the same voltage.

[0026] In some embodiments, the second ends of all of the first thermo-optical phase shifters and the second ends of all of the second thermo-optical phase shifters are connected to the same voltage.

[0027] In some embodiments, the resistances of all the first thermo-optical phase shifters and all the second thermo-optical phase shifters are the same.

[0028] In some embodiments, the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the spectroscopic section of the same stage are both the same, and when N is greater than 1, the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the spectroscopic section of the subsequent stage are both twice the resistance of the first thermal-optical phase shifter in the spectroscopic section of the previous stage.

[0029] 2 is a schematic diagram of an optical waveguide phased array of an optical waveguide phased array chip in some embodiments of the present invention. Referring to FIG. 2, the optical waveguide phased array includes three stages of splitting sections cascaded sequentially from left to right, where the first stage splitting section includes one optical waveguide branch, the second stage splitting section includes two optical waveguide branches, and the third stage splitting section includes four optical waveguide branches. The optical waveguide branches include a splitter 11, a first optical waveguide 121, a second optical waveguide 122, a first thermal-optical phase shifter 131, and a second thermal-optical phase shifter 132. The first thermal-optical phase shifter 131 is integrated on the first optical waveguide 132, and the second thermal-optical phase shifter 132 is integrated on the second optical waveguide 122. The first output port 1 of the splitter 11 is connected to the first output port 1 of the splitter 11. 12 is connected to the input end of the first optical waveguide 121, a second output port 113 of the spectrometer 11 is connected to the input end of the second optical waveguide 122, the output end of the first optical waveguide 121 and the output end of the second optical waveguide 122 in the first-stage spectrometer section are respectively connected to the input ports 111 of the two spectrometers 11 in the second-stage spectrometer section, the output end of the first optical waveguide 121 and the output end of the second optical waveguide 122 in the second-stage spectrometer section are respectively connected to the input ports 111 of the two spectrometers 11 in the third-stage spectrometer section, and the resistance of the first thermal-optical phase shifter 131 and the resistance of the second thermal-optical phase shifter 132 in the same optical waveguide branch are the same. In the optical waveguide phased array chip of the embodiment of the present invention, the output terminals of eight optical waveguides are formed through three stages of cascaded 1x2 splitters. Each stage has one thermo-optical phase shifter in each of the two waveguides after splitting, rather than only the last eight stages having eight phase shifters. Compared to the structure of conventional optical waveguide phased arrays, the cascaded splitting sections and phase shifters of the present invention alternate back and forth, rather than being two independent sections in front and back.

[0030] 3 is a schematic diagram of an optical waveguide phased array chip and a control voltage connection relationship in some embodiments of the present invention. Referring to FIG. 3, in the optical waveguide phased array chip, the input terminals of all the first thermal-optical phase shifters 131 are all connected to the same preset voltage V0, the input terminals of all the second thermal-optical phase shifters 132 are all connected to the ground pin GND, the output terminals of the first thermal-optical phase shifter 131 and the output terminals of the second thermal-optical phase shifter 132 in the same optical waveguide branch are connected to the same voltage, where in the first stage spectroscopic section, the output terminals of the first thermal-optical phase shifter 131 and the output terminals of the second thermal-optical phase shifter 132 in the optical waveguide branch are connected to voltage V1, and the voltages connected to the output terminals of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the two optical waveguide branches in the second stage spectroscopic section are are the V2 voltage and the V3 voltage, respectively, the voltages connected to the output terminals of the first thermal optical phase shifter 131 and the second thermal optical phase shifter 132 of the four optical waveguide branches in the third-stage spectroscopic section are the V4 voltage, the V5 voltage, the V6 voltage, and the V7 voltage, respectively, the two thermal phase shifter resistors connected to the V1 voltage are R1, the two thermal phase shifter resistors connected to the V2 voltage are R2, the two thermal phase shifter resistors connected to the V3 voltage are R3, the two thermal phase shifter resistors connected to the V4 voltage are R4, the two thermal phase shifter resistors connected to the V5 voltage are R5, the two thermal phase shifter resistors connected to the V6 voltage are R6, the two thermal phase shifter resistors connected to the V7 voltage are R7, and the resistance values ​​of R1 to R7 are all R.

[0031] The working principle of the optical waveguide phased array chip of the present invention will be described below by taking the optical waveguide phased array chip of the present invention in the embodiment of FIG. 3 as an example.

[0032] JPEG2025537615000002.jpg11170

[0033] JPEG2025537615000003.jpg11170 where A is a first coefficient, which is determined by the properties of the waveguide material and structure and can be obtained by measurement. This coefficient is well known in the industry and will not be further described here. Equation 2 is derived from Equation 1.

[0034] JPEG2025537615000004.jpg10170, where V0 is a preset voltage, Vk is the voltage connected to the first thermo-optic phase shifter 131 and the second thermo-optic phase shifter 132 in the optical waveguide branch of the same stage, Rk is the resistance of the first thermo-optic phase shifter 131 and the second thermo-optic phase shifter 132 connected to the same control voltage Vk, k is 1 to 7, and Δφ1 to Δφ7 refer to the phase differences between the phase shifters connected to V1 to V7, respectively, i.e., Δφ1 is the voltage V1 Δφ1 refers to the phase difference between two phase shifters connected to the V1 voltage end, Δφ2 refers to the phase difference between two phase shifters connected to the V2 voltage end, Δφ3 refers to the phase difference between two phase shifters connected to the V3 voltage end, Δφ4 refers to the phase difference between two phase shifters connected to the V4 voltage end, Δφ5 refers to the phase difference between two phase shifters connected to the V5 voltage end, Δφ6 refers to the phase difference between two phase shifters connected to the V6 voltage end, and Δφ7 refers to the phase difference between two phase shifters connected to the V7 voltage end.

[0035] As can be seen from Equation 1, Vk of both upper and lower arm phases 2The terms subtract and cancel each other, resulting in a phase difference Δφk that is linearly related to the applied voltage Vk. By adjusting voltages V1 through V7, the phase differences between the two arms after each spectrometer are sequentially such that Δφ1 is proportional to 4dφ, Δφ2 and Δφ3 are each proportional to 2dφ, and Δφ4, Δφ5, Δφ6, and Δφ7 are each proportional to dφ. Finally, the phase changes of the output light from the eight optical waveguides of the third spectrometer are sequentially 0, dφ, 2dφ, magic sound φ, 4dφ, 5dφ, 6dφ, and 7dφ from bottom to top after three stages of superposition. That is, there is a fixed phase difference dφ between each waveguide. In the optical waveguide phased array chip of the present invention, the phase change of the optical waveguides is linearly related to the required control voltage change, making it easy to control the optical waveguide phased array chip. Furthermore, when the number of cascaded spectroscopic sections is increased to four or more stages, the number of pins required is less than that of the conventional optical phased array chip, further simplifying the control of the phased array. Although this embodiment uses eight phased arrays as an example, the present invention is not limited thereto and can be extended to M, where M is an even number. When the number of optical paths in the phased array increases, for example to 64, 128, or more, the conventional phased array and its control become more complicated, and the beneficial effects of the optical waveguide phased array chip of the present invention become more pronounced.

[0036] 4 is a schematic diagram of an optical waveguide phased array chip according to some other embodiments of the present invention. Referring to FIG. 4, in the optical waveguide phased array chip, the output terminals of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the optical waveguide branch of the first-stage spectroscopic unit are connected to a voltage V1. The output terminals of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the two optical waveguide branches in the second-stage spectroscopic unit are both connected to a voltage V2. The output terminals of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the four optical waveguide branches in the third-stage spectroscopic unit are both connected to a voltage V3. The two thermal phase shifter resistors connected to the voltage V1 are R1, the two thermal phase shifter resistors connected to the voltage V2 are R2, and the two thermal phase shifter resistors connected to the voltage V3 are R3, where R1, R2, and R3 all have values ​​R.

[0037] The working principle of the optical waveguide phased array chip in the embodiment of FIG. 4 of the present invention is as follows.

[0038] In the above formula 1, Vk represents V1 to V3, and the phase difference between the upper and lower arms after splitting at each stage is proportional to the voltage applied to the stage. Δφ1 to Δφ3 represent the phase differences between the phase shifters connected to V1 to V3, respectively. That is, Δφ1 represents the phase difference between the two phase shifters in the first-stage splitting section, Δφ2 represents the phase difference between the two phase shifters under the same splitting waveguide branch in the second-stage splitting section, and Δφ3 represents the phase difference between the two phase shifters under the same optical waveguide branch in the third-stage splitting section. By adjusting the voltages V1, V2, and V3, the phase differences between the two arms after the three-stage splitting are, in order, Δφ1∝4dφ, Δφ2∝2dφ, and Δφ3∝dφ. Finally, the phase changes of the output light from the eight optical waveguides of the third splitting section are, from bottom to top, 0, dφ, 2dφ, 3dφ, 4dφ, 5dφ, 6dφ, and 7dφ, respectively, after three stages of superposition. This means that there is a fixed phase difference dφ between each waveguide. In the optical waveguide phased array chip of the present invention, the phase changes of the optical waveguides are linearly related to the required control voltage changes, which facilitates control of the optical waveguide phased array chip and reduces the number of pins required, simplifying phased array control.

[0039] 5 is a schematic diagram of an optical waveguide phased array chip according to some other embodiments of the present invention. Referring to FIG. 5, in the optical waveguide phased array chip, the output terminals of the first and second thermo-optic phase shifters 131 and 132 in the three-stage optical waveguide branches of the spectroscopic section are both connected to the V1 voltage. The resistance values ​​of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the first-stage spectroscopic section are both R, the resistance values ​​of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the second-stage spectroscopic section are both 2R, and the resistances of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the third-stage spectroscopic section are both twice the resistance of the first thermal-optical phase shifter 131 in the second-stage spectroscopic section, i.e., the resistances of the first thermal-optical phase shifter 131 and the second thermal-optical phase shifter 132 in the third-stage spectroscopic section are both 4R.

[0040] The working principle of the optical waveguide phased array chip in the embodiment of FIG. 5 of the present invention is as follows.

[0041] In the above formula 1, Vk is V1, the resistance values ​​of the thermo-optic phase shifters on the first-stage splitting section, the second-stage splitting section, and the third-stage splitting section are R, 2R, and 4R, respectively, and Δφ1 to Δφ3 indicate the phase differences between the phase shifters connected to V1 to V3, respectively. That is, Δφ1 indicates the phase difference between two phase shifters in the first-stage splitting section, Δφ2 indicates the phase difference between two phase shifters under the same splitting waveguide branch in the second-stage splitting section, and Δφ3 indicates the phase difference between two phase shifters in the third-stage splitting section. This refers to the phase difference between two phase shifters under the same optical waveguide branch in the optical section. A single control voltage ensures that the phase differences between both arms after three-stage splitting are Δφ1∝4dφ, Δφ2∝2dφ, and Δφ3∝dφ, respectively. Finally, the phase changes of the output light from the eight optical waveguides in the third splitting section are 0, dφ, 2dφ, 3dφ, 4dφ, 5dφ, 6dφ, and 7dφ, respectively, after three stages of superposition, meaning there is a fixed phase difference dφ between each waveguide. The control voltages for all thermo-optical phase shifters in each stage can be connected to the same pin, i.e., controlled by a single voltage V1, simplifying the control of the optical waveguide phased array chip and further reducing the number of pins.

[0042] In some embodiments, the voltages connected to the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter in the same optical waveguide branch are the sum of a DC voltage and a variable voltage, where the DC voltage is used to set an initial phase and the variable voltage is used to generate a phase change to further control beam scanning of a phased array.

[0043] In some specific embodiments, the voltage Vk applied to the first thermo-optic phase shifter 131 and the second thermo-optic phase shifter 132 in the same optical waveguide branch is a DC voltage Vk_0 plus a variable voltage Vk_t, i.e., Vk = Vk_0 + Vk_t, where k is a positive integer. Vk_0 is a DC voltage that can be used to set an initial phase for initial state calibration of the phased array. Vk_t is a variable voltage that generates a phase change and further controls the beam scanning of the phased array. The phase difference between the upper and lower arms in each spectroscopic section is linearly related to Vk_t. Compared to the conventional solution shown in FIG. 1 of the present application, when an initial phase calibration voltage is applied, the method for loading the control voltage is simplified; the control voltage in the conventional solution depends on the magnitude of the initial phase, the phase difference and the control voltage are not linearly related, and the nonlinear coefficients generated by different initial phases are different, which is relatively complicated and complex.

[0044] The present invention further provides a control method for the optical phased array chip, the control method including controlling so that the phase differences of the output waveguides between the first waveguide and the second waveguide adjacent to each other in the same spectroscopic unit are all the same, and when N is greater than 1, controlling so that the phase difference of the output waveguides between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the previous stage is twice the phase difference of the output waveguides between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the subsequent stage.

[0045] In some embodiments, a phase difference of an output waveguide between the first waveguide and the second waveguide adjacent to each other in the spectroscopic section of the same stage is controlled by adjusting a voltage connected to a second end of the first thermo-optical phase shifter and a second end of the second thermo-optical phase shifter in the spectroscopic section of the same stage, wherein adjusting the voltage connected to the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter in the spectroscopic section of the same stage as described above includes: Dividing the square of the preset voltage by the resistance of the first thermo-optic phase shifter in the spectroscopic unit of the same stage to be adjusted as first data; Dividing a phase difference of an output waveguide between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the same stage by a quotient of a first coefficient as second data; subtracting the difference of the second data from the first data as third data; Dividing the resistance of the first thermo-optic phase shifter in the spectroscopic unit of the same stage to be adjusted by twice the preset voltage as fourth data; The voltage connected to the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in the spectroscopic unit of the same stage is the product of the fourth data and the third data.

[0046] JPEG2025537615000005.jpg10170

[0047] JPEG2025537615000006.jpg10170 where A is a first coefficient, and the first coefficient A is determined by the properties of the waveguide material and structure. Equation 3 is derived from Equation 1.

[0048] JPEG2025537615000007.jpg10170Here, V0 is a preset voltage, Vk is a voltage connected to the first thermo-optical phase shifter 131 and the second thermo-optical phase shifter 132 in the optical waveguide branch of the same stage, Rk is the resistance of the first thermo-optical phase shifter 131 and the second thermo-optical phase shifter 132 connected to the same control voltage Vk, and k is a positive integer.

[0049] As can be seen from Equation 3, by adjusting the voltages connected to the second ends of the first and second thermo-optic phase shifters in the spectroscopic section of the same stage, Vk and the phase difference Δφ of the output waveguide between the first and second adjacent waveguides in the spectroscopic section of the same stage can be adjusted. k Control.

[0050] The control method for an optical waveguide phased array chip of the present invention provides a linear relationship between the phase change of the optical waveguide and the required control voltage change, which facilitates control of the optical waveguide phased array chip, reduces the number of required pins, and simplifies phased array control.

[0051] The present invention also provides an optical waveguide phased array system. Figure 6 is a schematic diagram of an optical waveguide phased array system according to some embodiments of the present invention. Referring to Figure 6, the optical waveguide phased array system of the present invention includes a control circuit 5, a sequentially connected light source 2, the optical phased array chip 1, a emitter 3, and an optical assembly system 4. The control circuit 5 is connected to the light source 2 and the optical phased array chip 1, respectively, and is used to control the light emission and optical phase. The optical waveguide phased array chip included in the optical waveguide phased array system of the present invention ensures that the phase change of the optical waveguide has a linear relationship with the required control voltage change, which facilitates control of the optical waveguide phased array chip and reduces the number of required pins, simplifying phased array control.

[0052] In some embodiments, all of the optical waveguide phased array system is integrated on the same chip. In other embodiments, only a portion of the optical waveguide phased array system is on the same chip.

[0053] In some embodiments, the light source is integrated into the optical waveguide phased array chip in a hetero-integrated or hybrid integration manner, while in other embodiments, the light source is an external light source that couples light into the optical waveguide phased array chip.

[0054] In some embodiments, the control circuitry and the optical waveguide phased array are integrated on the same chip, while in other embodiments, the optical waveguide phased array is external to the electrical chip or circuit board.

[0055] In some embodiments, the emitters are a one-dimensional array. In other embodiments, the emitters form a two-dimensional array or a three-dimensional array by waveguide paths. The emitters include, but are not limited to, waveguides, waveguide gratings, or Bragg reflectors.

[0056] In some embodiments, the optical assembly system includes, but is not limited to, a lens, a prism, a concave mirror, a resonant cavity, a filter, an amplifier, or an attenuator.

[0057] In some embodiments, the optical waveguide phased array system may not include an optical assembly system.

[0058] In some embodiments, the integrated material platform on which the optical waveguide phased array is located includes, but is not limited to, silicon, silicon-on-insulator, silicon-on-sapphire, silica, alumina, indium phosphide, lithium niobate, or a polymer.

[0059] In some embodiments, the waveguide types of the optical waveguide phased array include, but are not limited to, channel waveguides, ridge waveguides, slot waveguides, diffused waveguides, or photonic crystal waveguides.

[0060] In some embodiments, the waveguide material is the same material, while in other embodiments, the waveguide material uses different materials in different sections.

[0061] In some embodiments, the operating wavelength range of the phased array includes, but is not limited to, the visible band, O-band, E-band, S-band, C-band, L-band, U-band, and mid-infrared band.

[0062] In some embodiments, the operating wavelengths of the phased arrays may be the same fixed wavelength or may be variable wavelengths.

[0063] In some embodiments, the heating resistance material of the thermal phase shifter includes, but is not limited to, titanium nitride, doped silicon, or tungsten.

[0064] In some embodiments, the spectroscopic devices of the spectroscopic unit include, but are not limited to, a multimode interference spectrometer, a directional coupler, a bent coupler, an adiabatic spectrometer, a Y-junction, a trident coupler, a photonic crystal coupler, and a metamaterial coupler.

[0065] In some embodiments, the resistance R, 2R, or 4R requirements of the thermal phase shifter may allow for a certain tolerance, i.e., if there is a small deviation in resistance, the optical phased array chip and system can still operate effectively.

[0066] In some embodiments, applications of the phased array include laser radar, beam steering, optical sensing, optical interconnects, free-space optical communications, optical storage, or optical computing.

[0067] Although the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as defined by the appended claims. Furthermore, the present invention described herein may have other embodiments and may be practiced or realized in multiple ways.

Claims

1. an optical phased array chip including N-stage splitting units, N being a positive integer, the splitting units including one or more optical waveguide branches, each optical waveguide branch in each stage splitting unit including a splitter, a first optical waveguide, a second optical waveguide, a first thermal-optical phase shifter, and a second thermal-optical phase shifter, the first thermal-optical phase shifter being integrated on the first optical waveguide, the second thermal-optical phase shifter being integrated on the second optical waveguide, a first output port of the splitter being connected to a first end of the first optical waveguide, and a second output port of the splitter being connected to a first end of the second optical waveguide, and when N is greater than 1, each of the preceding splitting units in the preceding stage includes a splitter, a first optical waveguide, a second optical waveguide, a first thermal-optical phase shifter, and a second thermal-optical phase shifter, the first thermal-optical phase shifter being integrated on the first optical waveguide, the second thermal-optical phase shifter being integrated on the second optical waveguide, a first output port of the splitter being connected to a first end of the first optical waveguide, and a second output port of the splitter being connected to a first end of the second optical waveguide; an optical phase array chip, characterized in that the second end of the first thermal phase shifter and the second end of the second thermal phase shifter of the optical waveguide branch are respectively connected to input ports of two spectrometers in a subsequent spectroscopic section, the first end of the first thermal-optical phase shifter in each of the optical waveguide branches is connected to a predetermined voltage, the first end of the second thermal-optical phase shifter is grounded, the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in the same optical waveguide branch are connected to the same voltage, and the resistance of the first thermal-optical phase shifter and the resistance of the second thermal-optical phase shifter in the same optical waveguide branch are the same.

2. 2. The optical phased array chip of claim 1, wherein the voltage terminals connected to the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter in each of the optical waveguide branches are different from each other.

3. 2. The optical phased array chip according to claim 1, wherein in any one of the spectroscopic units, the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter are connected to the same voltage.

4. 3. The optical phased array chip of claim 2, wherein the second ends of all of the first thermo-optic phase shifters and the second ends of all of the second thermo-optic phase shifters are connected to the same voltage.

5. 3. The optical phased array chip according to claim 2, wherein the resistances of all the first thermo-optical phase shifters and all the second thermo-optical phase shifters are the same.

6. 5. The optical phase array chip of claim 4, wherein the resistances of the first and second thermo-optical phase shifters in the spectroscopic units of the same stage are the same, and when N is greater than 1, the resistances of the first and second thermo-optical phase shifters in the spectroscopic units of the subsequent stage are both twice the resistance of the first thermo-optical phase shifter in the spectroscopic units of the previous stage.

7. 2. The optical phase array chip of claim 1, wherein a voltage connected to the second end of the first thermo-optical phase shifter and the second end of the second thermo-optical phase shifter in the same optical waveguide branch is a sum of a DC voltage and a variable voltage, wherein the DC voltage is used to set an initial phase, and the variable voltage is used to generate a phase change to further control beam scanning of the phased array.

8. 2. The method for controlling the optical phased array chip according to claim 1, wherein the phase differences of the output waveguides between the adjacent first and second waveguides in the spectroscopic section of the same stage are controlled to be the same, and when N is greater than 1, the phase difference of the output waveguides between the adjacent first and second waveguides in the spectroscopic section of the previous stage is twice the phase difference of the output waveguides between the adjacent first and second waveguides in the spectroscopic section of the subsequent stage.

9. a phase difference of an output waveguide between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the same stage is controlled by adjusting a voltage connected to the second end of the first thermo-optic phase shifter and the second end of the second thermo-optic phase shifter in the spectroscopic unit of the same stage, wherein adjusting the voltage connected to the second end of the first thermo-optic phase shifter and the second end of the second thermo-optic phase shifter in the spectroscopic unit of the same stage as described above includes: Dividing the square of the preset voltage by the resistance of the first thermo-optic phase shifter in the spectroscopic unit of the same stage to be adjusted as first data; Dividing a phase difference of an output waveguide between the first waveguide and the second waveguide adjacent to each other in the spectroscopic unit of the same stage by a quotient of a first coefficient as second data; subtracting the difference of the second data from the first data as third data; Dividing the resistance of the first thermo-optic phase shifter in the spectroscopic unit of the same stage to be adjusted by twice the preset voltage as fourth data; The control method of claim 8, further comprising: a voltage connected to the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter in the spectroscopic section of the same stage is a product of the fourth data and the third data.

10. 10. An optical waveguide phased array system comprising a control circuit, a sequentially connected light source, the optical phased array chip of claim 1, a launcher, and an optical assembly system, wherein the control circuit is connected to the light source and the optical phased array chip, respectively, and is used to control the launch of light and the optical phase.

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