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 particularly to an optical phased array chip, a control method, and an optical waveguide phased array system.

Background Art

[0002] Optical Phased Arrays (OPAs) are widely applied in many fields, including lidar, imaging, free-space optical communication, laser ranging, etc. The implementation forms of optical phased arrays include liquid crystals, Microelectro Mechanical Systems (MEMS) devices, optical waveguides, etc. Here, optical waveguide phased arrays have attracted wide attention and been applied in recent years because they have characteristics such as a fast response speed, a low control voltage, a large scanning angle, and easy large-scale integration.

[0003] An optical phase shifter is a core component in an optical phased array, and mainly realizes a phase change through the electro-optic effect or thermo-optic effect of materials. Electro-optic phase shifters often introduce light absorption and change the light intensity while changing the optical phase, which is not desirable in the application of optical phased arrays. In contrast, the operating principle of a thermo-optic phase shifter is to install a heater (i.e., a resistor) around the waveguide and change the refractive index of the waveguide by heating to further change the phase of the light wave, and since it does not affect the light intensity, it is more widely applied.

[0004] Figure 1 is a schematic diagram of a conventional optical waveguide phased array chip. Referring to Figure 1, the optical waveguide phased array shows a spectrometer 11, optical waveguides 12 and a thermo-optical phase shifter 13, but does not show other components such as a light source or emitter. The cascaded spectrometer and phase shifter are two independent parts. On one optical waveguide phased array chip, light emitted from a light source is ultimately divided into nine beams via three cascaded 1x2 spectrometers within the chip. One thermo-optical phase shifter 13 is integrated on each of the eight optical waveguides 12 in the final stage. By applying a corresponding voltage or current to the eight thermo-optical phase shifters 13, the corresponding voltage or current depends on whether the control current is voltage-driven or current-driven, providing a fixed phase difference dφ to the light output by the eight optical waveguides, further interfering the eight wave sources at different positions, and 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 Figure 1, in order to generate a fixed phase difference dφ, it is necessary to apply different voltages or currents to the resistors of the eight thermal-optical phase shifters 13. Referring to the voltages V1 to V8 shown in Figure 1, the phases of the output light of 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, where P = V 2 / R,P=I 2 Because it is ×R, the phase has a nonlinear relationship with the applied voltage or current, making the control of the optical waveguide phased array complex. Furthermore, since the required phase differs for each optical waveguide, the required voltage or current to be applied also differs, further complicating the control. In addition, as mentioned above, nine electrical pins are required on the optical waveguide phased array chip containing the eight output optical channels, meaning that N channels require N+1 electrical pins, which is a large number and makes the control of the optical waveguide phased array complex.

[0006] Therefore, in order to solve the problems that exist in the conventional technology, it is necessary to provide a new type of optical phased array chip, control method, and optical waveguide phased array system. [Overview of the project] [Problems that the invention aims to solve]

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

[0008] To achieve the above objective, the optical phased array chip of the present invention includes N stages of spectrometers, where N is a positive integer, each spectrometer includes one or more optical waveguide branches, each optical waveguide branch in each stage of the spectrometer 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 being integrated on the first optical waveguide, the second thermal-optical phase shifter being integrated on the second optical waveguide, the first output port of the spectrometer being connected to the first end of the first optical waveguide, and the second output port of the spectrometer being connected to the first end of the second optical waveguide, and N is 1 If the value is also large, the second end of the first thermal phase shifter and the second end of the second thermal phase shifter at each optical waveguide branch in the preceding spectral section are connected to the input ports of the two spectrometers in the subsequent spectral section, the first end of the first thermal phase shifter at each optical waveguide branch is connected to a preset voltage, the first end of the second thermal phase shifter is grounded, the second end of the first thermal phase shifter and the second end of the second thermal phase shifter at the same optical waveguide branch are connected to the same voltage, and the resistance of the first thermal phase shifter and the resistance of the second thermal phase shifter at 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 it provides are linearly related, thereby facilitating the control of the optical waveguide phased array chip, reducing the number of required pins, and simplifying the control of the phased array.

[0010] Selectively, 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 at each optical waveguide branch are different.

[0011] Selectively, in either 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] Selectively, the second ends of all the first thermo-optical phase shifters and the second ends of all the second thermo-optical phase shifters are connected to the same voltage.

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

[0014] Selectively, when the resistance of the first thermo-optical phase shifter and the resistance of the second thermo-optical phase shifter in the same stage of the spectroscopic unit are the same and N is greater than 1, then the resistance of the first thermo-optical phase shifter and the resistance of the second thermo-optical phase shifter in the subsequent stage of the spectroscopic unit are both twice the resistance of the first thermo-optical phase shifter in the preceding stage of the spectroscopic unit.

[0015] Selectively, the voltage connected to the second end of the first thermal phase shifter and the second end of the second thermal phase shifter at the same optical waveguide branch is the sum of a DC voltage and a variable voltage, the DC voltage being used to set the initial phase and the variable voltage being used to generate a phase shift and further control the beam scanning of the phased array.

[0016] The present invention further provides a method for controlling the optical phased array chip, wherein the phase difference of the output waveguides between adjacent first and second waveguides in the same stage of the spectroscopic section is controlled to be the same, and when N is greater than 1, the phase difference of the output waveguides between adjacent first and second waveguides in the preceding spectroscopic section is twice the phase difference of the output waveguides between adjacent first and second waveguides in the subsequent spectroscopic section.

[0017] The beneficial effect of the optical waveguide phased array chip control method of the present invention is that it controls the change in phase difference between each optical waveguide in the optical phased array so that it has a linear relationship with the change in the required control voltage, thereby facilitating the control of the optical waveguide phased array chip, reducing the number of required pins, and simplifying the control of the phased array.

[0018] Selectively, the phase difference of the output waveguides between adjacent first and second waveguides in the spectroscopic section is controlled by adjusting 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 spectroscopic section of the same stage, where adjusting 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 spectroscopic section of the same stage, The square of the aforementioned preset voltage is divided as the first data by the resistance of the first thermo-optical phase shifter in the regulated spectral section of the same stage, The phase difference of the output waveguide between the adjacent first waveguide and the second waveguide in the same stage of the spectroscopic section is taken as the second data and divided by the quotient of the first coefficient, Subtracting the difference between the first data and the second data as the third data, The resistance of the first thermo-phase shifter in the regulated spectroscopic section is divided by twice the preset voltage as a fourth data point. 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 same-stage spectroscopic unit includes that it 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 light source connected in sequence, the optical phased array chip, an emitter, and an optical assembly system. The control circuit is connected to the light source and the optical phased array chip respectively and is used to control the emission of light and the optical phase.

Advantages of the Invention

[0020] The beneficial effect of the optical phased array system of the present invention is that the phase difference change and the control voltage change between the waveguides of the optical phased array chip in the optical phased array system have a linear relationship, which simplifies the control method of the phased array and can reduce the required electrical pins.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic diagram of an optical waveguide phased array chip of the prior art. [Figure 2] It is a schematic diagram of an optical waveguide phased array of an optical waveguide phased array chip in some embodiments of the present invention. [Figure 3] It is a schematic diagram of an optical waveguide phased array chip and a control voltage connection relationship in some embodiments of the present invention. [Figure 4] It is a schematic diagram of an optical waveguide phased array chip in some other embodiments of the present invention. [Figure 5] It is a schematic diagram of an optical waveguide phased array chip in some other embodiments of the present invention. [Figure 6] It is a schematic diagram of an optical waveguide phased array system in some embodiments of the present invention.

Embodiments for Carrying Out the Invention

[0022] To further clarify the object, technical proposal, and advantages of the present invention, the technical proposal in embodiments of the present invention will be clearly and completely described below, with reference to the drawings of the present invention. It is clear that the embodiments described are only a part of, and not all, embodiments of the present invention. All other embodiments obtained based on the embodiments of the present invention without the creative effort of a person skilled in the art are all within the scope of the protection of the present invention. Unless otherwise defined, technical or scientific terms used herein are in the ordinary sense understood by a person skilled in the art. Similar words used herein, such as “include,” mean that the element or thing that appears before the word includes the element or thing listed after the word, and their equivalents, but do not exclude other elements or things.

[0023] In response to the problems of the prior art, an embodiment of the present invention provides an optical phased array chip including an N-stage spectrometer, where N is a positive integer, the spectrometer includes one or more optical waveguide branches, each optical waveguide branch in each stage of the spectrometer includes a spectrometer, a first optical waveguide, a second optical waveguide, a first thermo-optical phase shifter, and a second thermo-optical phase shifter, wherein the first thermo-optical phase shifter is integrated on the first optical waveguide, the second thermo-optical phase shifter is integrated on the second optical waveguide, the first output port of the spectrometer is connected to the first end of the first optical waveguide, and the second output port of the spectrometer is connected to the first end of the second optical waveguide. When N is greater than 1, the second end of the first thermal phase shifter at each optical waveguide branch in the preceding spectroscopic unit is connected to the input ports of the two spectrometers in the subsequent spectroscopic unit, the first end of the first thermal phase shifter at each optical waveguide branch is connected to a preset voltage, the first end of the second thermal phase shifter is grounded, the second end of the first thermal phase shifter at the same optical waveguide branch is connected to the same voltage, and the resistance of the first thermal phase shifter at the same optical waveguide branch is the same as the resistance of the second thermal phase shifter.

[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 at each optical waveguide branch 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 the first thermal phase shifters and the second ends of all the second thermal phase shifters are connected to the same voltage.

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

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

[0029] Figure 2 is a schematic diagram of an optical waveguide phased array chip in several embodiments of the present invention. Referring to Figure 2, the optical waveguide phased array includes three stages of spectrometers sequentially cascaded from left to right, the first stage of the spectrometer including one optical waveguide branch, the second stage of the spectrometer including two optical waveguide branches, and the third stage of the spectrometer including four optical waveguide branches, the optical waveguide branches including a spectrometer 11, a first optical waveguide 121, a second optical waveguide 122, a first thermo-optical phase shifter 131, and a second thermo-optical phase shifter 132, the first thermo-optical phase shifter 131 being integrated on the first optical waveguide 132, the second thermo-optical phase shifter 132 being integrated on the second optical waveguide 122, and the first output port 1 of the spectrometer 11 12 is connected to the input terminal of the first optical waveguide 121, the second output port 113 of the spectrometer 11 is connected to the input terminal of the second optical waveguide 122, the output terminals of the first optical waveguide 121 and the output terminals of the second optical waveguide 122 in the first stage spectroscopic section are connected to the input ports 111 of the two spectrometers 11 in the second stage spectroscopic section, the output terminals of the first optical waveguide 121 and the output terminals of the second optical waveguide 122 in the second stage spectroscopic section are connected to the input ports 111 of the two spectrometers 11 in the third stage spectroscopic section, and the resistance of the first thermo-optical phase shifter 131 and the resistance of the second thermo-optical phase shifter 132 at the same optical waveguide branch are the same. In the embodiment of the present invention, the optical waveguide phased array chip forms the output terminals of eight optical waveguides via three cascaded 1x2 spectrometers, with one thermo-optical phase shifter in each of the two waveguides after spectral analysis in each stage. Unlike conventional optical waveguide phased arrays, the cascaded spectrometer and phase shifters of the present invention alternate front and back, rather than being two separate front and back sections.

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

[0031] In the following, the operating principle of the optical waveguide phased array chip of the present invention will be explained using the optical waveguide phased array chip in the embodiment shown in Figure 3 as an example.

[0032] JPEG0007895671000001.jpg11170

[0033] JPEG0007895671000002.jpg11170 Here, A is the first coefficient, and the said first coefficient A 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 explained further here. Equation 2 is derived from Equation 1.

[0034] JPEG0007895671000003.jpg10170 Here, V0 is a preset voltage, Vk is the 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, k is 1 to 7, and Δφ1 to Δφ7 refer to the phase difference between the phase shifters connected to V1 to V7, respectively, that is, Δφ1 is the V1 voltage Δφ2 refers to the phase difference between two phase shifters connected to the terminal, Δφ3 refers to the phase difference between two phase shifters connected to the V3 voltage terminal, Δφ4 refers to the phase difference between two phase shifters connected to the V4 voltage terminal, Δφ5 refers to the phase difference between two phase shifters connected to the V5 voltage terminal, Δφ6 refers to the phase difference between two phase shifters connected to the V6 voltage terminal, and Δφ7 refers to the phase difference between two phase shifters connected to the V7 voltage terminal.

[0035] As can be seen from Equation 1, the Vk phase of both the upper and lower arms 2The terms are subtracted and canceled out, and finally the phase difference Δφk has a linear relationship with the applied voltage Vk. By adjusting the voltages V1 to V7, the phase differences between the two arms after each spectrometer are sequentially such that Δφ1 is proportional to 4dφ, Δφ2 and Δφ3 are proportional to 2dφ, Δφ4, Δφ5, Δφ6 and Δφ7 are proportional to dφ, and finally, after the phase changes of the eight optical waveguide output light of the third stage spectrometer are superimposed in three stages, they are sequentially 0, dφ, 2dφ, magic sound φ, 4dφ, 5dφ, 6dφ, and 7dφ from bottom to top, i.e., 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 waveguide and the change of the required control voltage have a linear relationship, making it easier to control the optical waveguide phased array chip. Furthermore, when increasing the number of cascaded connections in the spectroscopic section to four or more stages, the number of required pins is less than that of conventional optical phased array chips, further simplifying the control of the phased array. In this embodiment, eight phased arrays are used as an example, but 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, conventional phased arrays and their control become more complex, and the beneficial effects of the optical waveguide phased array chip of the present invention become more pronounced.

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

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

[0038] In Equation 1, Vk is V1 to V3, and the phase difference between the upper and lower arms after spectral analysis of each stage is proportional to the voltage applied to that stage. Δφ1 to Δφ3 refer to the phase differences between the phase shifters connected to V1 to V3, respectively. That is, Δφ1 refers to the phase difference between the two phase shifters in the first stage spectral section, Δφ2 refers to the phase difference between the two phase shifters under the same spectral waveguide branch in the second stage spectral section, and Δφ3 refers to the phase difference between the two phase shifters under the same optical waveguide branch in the third stage spectral section. By adjusting voltages V1, V2, and V3, the phase difference between the two arms after three stages of spectral analysis is sequentially Δφ1∝4dφ, Δφ2∝2dφ, Δφ3∝dφ, and finally, after the phase changes of the eight optical waveguide output lights of the third stage spectral section are superimposed in three stages, they become sequentially 0, dφ, 2dφ, 3dφ, 4dφ, 5dφ, 6dφ, and 7dφ from bottom to top, meaning 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 waveguide and the required control voltage change have a linear relationship, which facilitates the control of the optical waveguide phased array chip, reduces the number of required pins, and simplifies the control of the phased array.

[0039] Figure 5 is a schematic diagram of an optical waveguide phased array chip in yet another embodiment of the present invention. Referring to Figure 5, in the optical waveguide phased array chip, the output terminals of the first thermo-optical phase shifter 131 and the second thermo-optical phase shifter 132 at the optical waveguide branching of the three-stage spectroscopic section are both connected to the V1 voltage. In the first stage of the spectroscopic unit, the resistance values ​​of the first thermo-phase shifter 131 and the second thermo-phase shifter 132 are both R; in the second stage of the spectroscopic unit, the resistance values ​​of the first thermo-phase shifter 131 and the second thermo-phase shifter 132 are both 2R; and in the third stage of the spectroscopic unit, the resistances of the first thermo-phase shifter 131 and the second thermo-phase shifter 132 are both twice the resistance of the first thermo-phase shifter 131 in the second stage of the spectroscopic unit, that is, the resistances of the first thermo-phase shifter 131 and the second thermo-phase shifter 132 in the third stage of the spectroscopic unit are both 4R.

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

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

[0042] In some embodiments, the voltage connected to the second end of the first thermal phase shifter and the second end of the second thermal phase shifter at the same optical waveguide branch is the sum of a DC voltage and a variable voltage, the DC voltage being used to set the initial phase and the variable voltage being used to generate a phase change and further control the beam scanning of the phased array.

[0043] In some specific embodiments, the voltage Vk connected to the first thermo-optical phase shifter 131 and the second thermo-optical phase shifter 132 at the optical waveguide branching stage is the sum of a DC voltage Vk_0 and a variable voltage Vk_t, i.e., Vk = Vk_0 + Vk_t, where k is a positive integer, and Vk_0 is a DC voltage that can be used to set the initial phase for initial state calibration of the phased array. Vk_t is a variable voltage that generates a phase change to further control 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 scheme in Figure 1 of this application, when an initial phase calibration voltage is applied, the method of loading the control voltage is simplified, whereas in the conventional scheme, the control voltage depends on the magnitude of the initial phase, the phase difference and the control voltage are not linearly related, and the nonlinear coefficients generated from different initial phases are different, making it relatively cumbersome and complex.

[0044] The present invention further provides a method for controlling the optical phased array chip, the method comprising controlling the output waveguides between adjacent first and second waveguides in the same stage of the spectroscopic section so that the phase difference between them is the same, and when N is greater than 1, the phase difference between the output waveguides between adjacent first and second waveguides in the preceding spectroscopic section is twice the phase difference between the output waveguides between adjacent first and second waveguides in the subsequent spectroscopic section.

[0045] In some embodiments, the phase difference of the output waveguides between adjacent first and second waveguides in the spectroscopic section is controlled by adjusting 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 spectroscopic section of the same stage, where adjusting 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 spectroscopic section of the same stage, The square of the aforementioned preset voltage is divided as the first data by the resistance of the first thermo-optical phase shifter in the regulated spectral section of the same stage, The phase difference of the output waveguide between the adjacent first waveguide and the second waveguide in the same stage of the spectroscopic section is taken as the second data and divided by the quotient of the first coefficient, Subtracting the difference between the first data and the second data as the third data, The resistance of the first thermo-phase shifter in the regulated spectroscopic section is divided by twice the preset voltage as a fourth data point. 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 is the product of the fourth data and the third data.

[0046] JPEG0007895671000004.jpg10170

[0047] JPEG0007895671000005.jpg10170 Here, A is the 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] JPEG0007895671000006.jpg10170 Here, V0 is a preset voltage, Vk is the 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, Vk and the phase difference Δφ of the output waveguide between adjacent first and second waveguides in the same stage of the spectroscopic section are adjusted by 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 same stage of the spectroscopic section. k Control.

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

[0051] The present invention further provides an optical waveguide phased array system. Figure 6 is a schematic diagram of an optical waveguide phased array system in 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, sequentially connected light sources 2, the optical phased array chip 1, a emitter 3, and an optical assembly system 4, wherein the control circuit 5 is connected to the light sources 2 and the optical phased array chip 1 respectively and is used to control the emission of light and the optical phase. The optical waveguide phased array chip included in the optical waveguide phased array system of the present invention simplifies the control of the phased array by facilitating the control of the optical waveguide phased array chip and reducing the number of required pins, thereby simplifying the control of the phased array.

[0052] In some embodiments, the entire 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 located on the same chip.

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

[0054] In some embodiments, the control circuit and the optical waveguide phased array are integrated on the same chip. In other embodiments, an electrical chip or circuit board is attached externally to the optical waveguide phased array.

[0055] In some embodiments, the launcher is a one-dimensional array. In other embodiments, the launcher forms a two-dimensional or three-dimensional array by waveguide paths. The launcher includes, but is not limited to, waveguides, waveguide grids, or Bragg reflectors.

[0056] In some embodiments, the optical assembly system includes, but is not limited to, lenses, prisms, concave mirrors, resonant cavities, filters, amplifiers, or attenuators.

[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 polymers.

[0059] In some embodiments, the waveguide type of the optical waveguide phased array includes, but is not limited to, channel waveguides, ridge waveguides, slot waveguides, diffuse 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 light band, O band, E band, S band, C band, L band, U band, and mid-infrared band.

[0062] In some embodiments, the operating wavelength of the phased array may be a fixed wavelength or a variable wavelength.

[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 device of the spectroscopic unit includes, but is not limited to, a multimode interference spectrometer, a directional coupler, a bent coupler, an adiabatic spectrometer, a Y-branch, a trident coupler, a photonic crystal coupler, and a metamaterial coupler.

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

[0066] In some embodiments, the application areas of the phased array include laser radar, beam control, optical sensing, optical interconnects, free-space optical communication, optical storage, or optical computing.

[0067] Although 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 changes are possible to these embodiments. However, it should be understood that such modifications and changes fall within the scope and spirit of the present invention as defined in the claims. Furthermore, the present invention described herein may have other embodiments and may be carried out or realized in multiple ways.

Claims

1. An optical phased array chip including an N-stage spectroscopic section, N is a positive integer, The spectroscopic section includes one or more optical waveguide branches, Each optical waveguide branch in the spectroscopic section of each stage includes a spectrometer, a first optical waveguide, a second optical waveguide, a first thermal phase shifter, and a second thermal 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, the first output port of the spectrometer is connected to the first end of the first optical waveguide, and the second output port of the spectrometer is connected to the first end of the second optical waveguide. At each optical waveguide branch, the first end of the first thermal-optical phase shifter is connected to a preset voltage, the first end of the second thermal-optical phase shifter is grounded, and the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter at the same optical waveguide branch 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. An optical phased array chip characterized in that, 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 optical waveguide branch in the preceding spectroscopic unit are connected to the input ports of the two spectrometers in the subsequent spectroscopic unit, respectively.

2. The optical phased array chip according to claim 1, characterized in that the voltage terminals connected to the second end of the first thermal-optical phase shifter and the second end of the second thermal-optical phase shifter at each optical waveguide branch are different.

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

4. The optical phased array chip according to claim 2, characterized in that the second ends of all the first thermal phase shifters and the second ends of all the second thermal phase shifters are connected to the same voltage.

5. The optical phased array chip according to claim 2, characterized in that the resistances of all the first thermal phase shifters and the second thermal phase shifters are all the same.

6. The optical phased array chip according to claim 4, characterized in that, when the resistance of the first thermo-optical phase shifter and the resistance of the second thermo-optical phase shifter in the same stage of the spectroscopic unit are the same, and N is greater than 1, the resistance of the first thermo-optical phase shifter and the resistance of the second thermo-optical phase shifter in the subsequent stage of the spectroscopic unit are both twice the resistance of the first thermo-optical phase shifter in the preceding stage of the spectroscopic unit.

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

8. A control method for the optical phased array chip, characterized in that the phase difference of the output waveguides between adjacent first and second optical waveguides in the same stage of the spectroscopic unit is controlled to be the same, and when N is greater than 1, the phase difference of the output waveguides between adjacent first and second optical waveguides in the preceding spectroscopic unit is twice the phase difference of the output waveguides between adjacent first and second optical waveguides in the subsequent spectroscopic unit.

9. By adjusting the voltage connected to the second end of the first thermal phase shifter and the second end of the second thermal phase shifter in the same stage of the spectroscopic section, the phase difference of the output waveguides between adjacent first and second optical waveguides in the same stage of the spectroscopic section is controlled, and here, adjusting the voltage connected to the second end of the first thermal phase shifter and the second end of the second thermal phase shifter in the same stage of the spectroscopic section as described above, The square of the aforementioned preset voltage is divided as the first data by the resistance of the first thermo-optical phase shifter in the regulated spectral section of the same stage, The phase difference of the output waveguides between the adjacent first optical waveguide and the second optical waveguide in the same stage of the spectroscopic section is divided by the quotient of the first coefficient as the second data, Subtracting the difference between the first data and the second data as the third data, The resistance of the first thermo-phase shifter in the regulated spectroscopic section is divided by twice the preset voltage as a fourth data point. The control method according to claim 8, characterized in that the voltage connected to the second end of the first thermal phase shifter and the second end of the second thermal phase shifter in the same stage of the spectroscopic unit is the product of the fourth data and the third data.

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

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