Silicon optical chip and gyroscope performance universal testing device and method

Abstract

The invention provides a device and a method for universally testing the performance of a silicon optical chip and a gyroscope. The device comprises a chip and gyroscope measurement and control module, an external light source module, an external phase modulator, an optical fiber loop and a light source module, wherein the chip and gyroscope measurement and control module comprises a driving and temperature control unit, a power supply control unit, an electric switch control unit, an optical switch control unit, a signal generation unit and an acquisition and control unit and is used for testing instruction processing and data processing, and the light source module is used for providing stable optical power input for a silicon optical chip without a light source. The analog electric switch controls the signal generation unit to output signals which are respectively applied to the phase modulator on the silicon optical chip or the external phase modulator, and the four optical switches form three test channels and are communicated with the external phase modulator and the optical fiber loop to form a gyroscope optical path. According to the invention, the universal test of the performance of different types of silicon optical chips and gyroscopes can be realized, and the accuracy and timeliness of the test are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical gyroscopes, and in particular relates to a silicon photonic chip and a universal testing device and method for gyroscope performance. Background Art

[0002] Industries such as autonomous driving and drones have urgent demands for inertial navigation systems that are low-cost, miniaturized, and highly reliable. Depending on the accuracy, the system cost is usually controlled between one thousand and ten thousand yuan, and it must be mass-produced. Gyroscopes are the core sensors of inertial navigation systems, especially fiber optic gyroscopes, which have been widely used in various fields such as sea, land, air, and space due to their high precision, all-solid-state, no rotating parts, and high reliability. However, the optical path of traditional interferometric fiber optic gyroscopes contains multiple discrete optical devices, multiple melting points, and multiple sections of pigtails that need to be processed, resulting in complex production processes, large volumes, high costs, and low yields for fiber optic gyroscopes. Therefore, the low-cost and miniaturized development of traditional fiber optic gyroscopes faces huge challenges.

[0003] In recent years, silicon-based optical chips have made breakthroughs and have been widely used in the field of optical communications, providing new ideas for the integration, miniaturization and low cost of fiber optic gyroscopes: replacing the discrete optical devices of traditional fiber optic gyroscopes with silicon-based optical chips, their size, weight, cost and power consumption will be greatly reduced. Silicon photonic gyroscopes have become an important development direction for gyro inertial devices.

[0004] In the past three years, many units at home and abroad have carried out the research and development of silicon-based optical chips. Couplers can be directly processed on silicon substrates, and detectors can also be easily integrated through silicon-based germanium growth processes. Therefore, the integration solution usually includes couplers and detectors, while the light source and modulator need to be realized through bonding, lens coupling, etc. Therefore, according to the different types of integrated devices, silicon-based optical chips mainly include the following categories: light source / detector / coupler integrated transceiver chip, detector / coupler / modulator integrated transceiver-modulator chip, light source / detector / coupler / modulator integrated transceiver-modulator chip, and according to the different types of detectors, they are divided into PIN type, PIN-FET type and PIN-TIA type, all with different output types (PIN output is current, PIN-FET output is single-ended voltage, PIN-TIA output is differential voltage). Different device integration types and output methods make the performance test of silicon-based optical chips complicated, which will further delay the application speed of the device and delay the integration, miniaturization and low-cost development of fiber optic gyroscopes.

[0005] In summary, there is an urgent need for a universal silicon photonic chip testing method and device that can realize universal testing of silicon photonic chips based on different unit categories and different output modes, and also needs to have gyroscope-level verification functions to lay the foundation for the continuous improvement and application of silicon photonic chips in the future. Summary of the invention

[0006] In order to solve the technical problem that different types of silicon photonic chips are difficult to test universally, the present invention provides a universal testing device and method for silicon photonic chips and gyroscope performance, which are used to realize universal testing of different types of silicon photonic chips and gyroscope performance.

[0007] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0008] The present invention provides a silicon photonic chip and a universal testing device for gyroscope performance, comprising:

[0009] The chip and gyro measurement and control module include the following units:

[0010] Driving and temperature control unit, used for constant current driving and temperature control of light sources on silicon photonic chips;

[0011] A power control unit, used to power detectors on silicon photonic chips;

[0012] An electric switch control unit, used to control the gating mode of the analog electric switch according to the analog electric switch control instruction, and apply the modulation signal output by the signal generating unit to the phase modulator in the silicon photonic chip or to the external phase modulator;

[0013] An optical switch control unit, used to control the gating mode of the optical switch according to the optical switch control instruction, and control the silicon photonic chip to output laser signals into different test channels;

[0014] A signal generating unit, used to generate a modulation signal for testing the phase modulator and a modulation signal for the gyroscope to work normally;

[0015] The acquisition and control unit is used to control the operation of each unit and collect test signals to carry out chip and gyroscope performance tests;

[0016] A light source module is used to provide a stable optical power input to a silicon photonic chip without a light source and is connected to an input optical port of the silicon photonic chip;

[0017] An analog electric switch, wherein the input end of the analog electric switch is connected to the electric switch control unit, and the output end includes two channels, which are respectively connected to the modulation port of the phase modulator on the silicon photonic chip and the modulation port of the external phase modulator;

[0018] The optical switches include four optical switches, wherein the inputs of the first and second optical switches are respectively connected to the two optical ports of the silicon photonic chip, the two outputs of the first optical switch are respectively connected to the extinction ratio test channel and the input of the third optical switch, one output of the second optical switch is connected to the input of the fourth optical switch, the two outputs of the third optical switch are respectively connected to the first optical power test channel and the first port of the external phase modulator, and the two outputs of the fourth optical switch are respectively connected to the second optical power test channel and the second port of the external phase modulator;

[0019] The output end of the external phase modulator is connected to a standard fiber optic loop.

[0020] Furthermore, the analog electric switch also includes an instruction control terminal, which is used to switch the connection mode of the modulation port according to the analog electric switch control instruction output by the chip and the gyro measurement and control module;

[0021] Each optical switch also includes an instruction control terminal for receiving an optical switch control instruction output by the chip and the gyro measurement and control module, and adjusting the gating mode of each optical switch.

[0022] Furthermore, the acquisition and control unit includes:

[0023] A splitting ratio test unit, which collects the output lasers of the first and second optical power test channels and calculates the splitting ratio;

[0024] An extinction ratio test unit collects the output laser of the extinction ratio test channel and calculates the extinction ratio;

[0025] An optical power test unit collects the output lasers of the first and second optical power test channels and calculates the optical power;

[0026] A photocurrent processing module, used to convert the photocurrent output by the PIN detector into a voltage;

[0027] A differential voltage processing module, used for amplifying the differential voltage output by the FET type detector;

[0028] A single-ended voltage processing module is used to amplify the single-ended voltage output by the TIA type detector;

[0029] The demodulation module is used to collect the detector output signal, obtain the closed-loop control digital signal by demodulating the speed signal, generate a closed-loop voltage signal, and apply it to the phase modulator inside the silicon photonic chip or to an external phase modulator;

[0030] A half-wave voltage test module collects the output signal of the detector and determines the half-wave voltage of the phase modulator;

[0031] The modulation bandwidth test module collects the output signal of the detector and determines the modulation bandwidth of the phase modulator.

[0032] Furthermore, the test instructions of the universal testing device include chip selection words, detector selection words, chip test category words, and gyroscope test words. The chip selection words include emission bits, detection bits, and modulation bits. The detector selection words include PIN bits, TIA bits, and FET bits. The chip test category words include half-wave voltage bits, modulation bandwidth bits, saturation voltage bits, light-free bias bits, extinction ratio bits, splitting ratio bits, and optical power bits. The gyroscope test words include zero bias bits, precision bits, and scale bits.

[0033] Furthermore, the test instruction also includes additional words, and the additional words are used to increase the test index. The present invention also provides a universal test method for silicon photonic chips and gyroscope performance, comprising the following steps:

[0034] S1, connect the silicon photonic chip to be tested to a universal testing device, receive a test instruction, if it includes silicon photonic chip testing, go to step S2, if it includes gyroscope testing, go to step S6;

[0035] S2, determine the type of silicon photonic chip, if the silicon photonic chip includes a light source, proceed to step S3, if the silicon photonic chip includes a detector, proceed to step S4, if the silicon photonic chip includes a phase modulator, proceed to step S5;

[0036] S3, the light source works and the test category of the silicon photonic chip is read;

[0037] The determination includes an extinction ratio test, controlling the extinction ratio test channel of the first optical switch to be connected, collecting output laser light, and calculating the extinction ratio;

[0038] The judgment includes a splitting ratio test, controlling the first and second optical power test channels of the optical switch to be connected, collecting output lasers, and calculating the splitting ratio;

[0039] The judgment includes an optical power test, controlling the first and second optical power test channels of the optical switch to be connected, collecting output lasers, and calculating optical power;

[0040] S4, the detector works and reads the test category of the silicon photonic chip;

[0041] The judgment includes a saturation voltage test, which controls the drive current to change at a set rate until the voltage reaches saturation and records the saturation voltage value;

[0042] The judgment includes a no-light bias test, setting the drive current to 0 and recording the no-light bias value;

[0043] S5, the phase modulator works, the light source on the silicon photonic chip or the external light source module, the silicon photonic chip and the optical fiber ring work to form a gyroscope optical path, the analog electric switch controls the modulation signal to be applied to the silicon photonic chip phase modulator, and the silicon photonic chip test category is read;

[0044] The judgment includes a half-wave voltage test, in which the signal generating unit generates a sawtooth wave signal of a set frequency, collects the detector output signal, and records the half-wave voltage;

[0045] The judgment includes a modulation bandwidth test, in which the signal generating unit generates a sine wave signal of a set frequency, collects the detector output signal, and records the modulation bandwidth;

[0046] S6, determining whether the silicon photonic chip is integrated with a phase modulator, if yes, proceeding to step S7, otherwise proceeding to step S9;

[0047] S7, the phase modulator works, the analog electric switch controls the modulation signal to be applied to the phase modulator of the silicon photonic chip, the optical switch is controlled to be connected with the channel of the external phase modulator and the optical fiber ring, no modulation signal is applied to the external phase modulator, the light source on the silicon photonic chip or the external light source module, the silicon photonic chip and the optical fiber ring work, and form the gyroscope optical path;

[0048] S8, collecting the detector output signal, outputting a closed-loop voltage signal through voltage sampling and speed demodulation, applying it to the silicon photonic chip phase modulator, and performing zero bias, accuracy, and scale tests according to the test category;

[0049] S9, controlling the optical switch to communicate with the channel of the external phase modulator and the optical fiber loop, applying the analog electrical switch to control the modulation signal to the external phase modulator, and making the light source on the silicon photonic chip or the external light source module, the silicon photonic chip, the external phase modulator, and the optical fiber loop work to form a gyroscope optical path;

[0050] S10, collecting the detector output signal, outputting a closed-loop voltage signal through voltage sampling and speed demodulation, applying it to an external phase modulator, and performing zero bias, accuracy, and scale tests according to the test category.

[0051] Furthermore, the test instruction includes a chip selection word, a detector selection word, a chip test category word, and a gyroscope test word. The chip selection word includes an emission bit, a detection bit, and a modulation bit. The detector selection word includes a PIN bit, a TIA bit, and a FET bit. The chip test category word includes a half-wave voltage bit, a modulation bandwidth bit, a saturation voltage bit, a lightless bias bit, an extinction ratio bit, a splitting ratio bit, and an optical power bit. The gyroscope test word includes a zero bias bit, an accuracy bit, and a scale bit. Automatic testing is performed according to the values ​​of the words and bits.

[0052] Furthermore, the test instruction also includes additional words, and the additional words are used to increase the test index.

[0053] Furthermore, the detector is of PIN type, FET type, or TIA type, and the universal testing method also includes the step of determining the type of the detector, and processing the output signal according to the type of the detector to obtain an output voltage that meets the sampling voltage requirements.

[0054] The beneficial effects of the present invention compared with the prior art are as follows:

[0055] The universal testing device and method for silicon photonic chips and gyroscope performance provided by the present invention can realize universal testing of different silicon photonic chip types and different detector output modes, and can be compatible with different silicon photonic chip design categories, thereby improving the universality of silicon photonic chip testing. It has a gyroscope-level verification function, and can establish a mapping relationship between silicon photonic chip performance and gyroscope performance, thus laying a foundation for the continuous improvement and application of silicon photonic chips.

[0056] The silicon photonic chip and gyroscope performance universal test device provided by the present invention has a simple structure and is easy to operate. After the silicon photonic chip to be tested is assembled once, no human intervention is required, and fully automated test output can be achieved, thereby ensuring the reliability and safety of the test process. At the same time, the inconsistency of the test environment caused by human intervention is avoided.

[0057] The universal testing method for silicon photonic chips and gyroscope performance provided by the present invention has a simple process and carries out gyroscope-level testing on the basis of chip-level testing, thereby ensuring the accuracy and timeliness of the test. The testing method uses test instructions (including test words and test bits) throughout the whole process, and the method is simple and efficient, and the test is fully automated, which can meet the test of batch silicon photonic chips and gyroscopes and is suitable for engineering implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0059] Figure 1 A schematic diagram of the structure of a silicon photonic chip and a universal gyroscope performance testing device provided by a specific embodiment of the present invention;

[0060] Figure 2 This is a principle block diagram of the universal test instructions for silicon photonic chips and gyroscopes provided in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0061] Specific embodiments of the present invention are described in detail below. In the following description, for the purpose of explanation and not limitation, specific details are set forth to help fully understand the present invention. However, it will be apparent to those skilled in the art that the present invention may also be practiced in other embodiments that depart from these specific details.

[0062] It should be noted that in order to avoid obscuring the present invention due to unnecessary details, only the device structure and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0063] As one aspect of the present invention, a general testing device for silicon photonic chips and gyroscope performance is provided. Figure 1 As shown, it mainly includes a chip and gyro measurement and control module, a 2*4 analog electrical switch, four 1*2 optical switches, an external phase modulator and an optical fiber ring, as well as the silicon photonic chip to be tested.

[0064] The chip and gyro measurement and control module, as the core processing module of the universal test device, integrates the following functional units:

[0065] The driving and temperature control unit is used for constant current driving and temperature control of the light source part in the silicon photonic chip, ensuring that it can maintain stable optical power output, laying the foundation for the splitting ratio, extinction ratio and optical power testing of the silicon photonic chip; the driving and temperature control unit is connected to the driving and temperature control ports of the light source on the silicon photonic chip. If there is no integrated light source part in the silicon photonic chip, the output end of the driving and temperature control unit is vacant.

[0066] The power control unit is used to output positive and negative power supplies that meet the power supply requirements of the detectors on the silicon photonic chip. Different power supply voltages are output according to the type of detector (PIN, FET or TIA), laying the foundation for the light-free bias and saturation voltage testing of the detector part in the silicon photonic chip. The method of outputting different power supply voltages is a well-known technology and will not be repeated here.

[0067] The electric switch control unit is used to control the gating mode of the analog electric switch according to the analog electric switch control instruction, and apply the modulation signal output by the signal generating unit to the internal phase modulator integrated on the silicon photonic chip or the external phase modulator.

[0068] The optical switch control unit is used to control the gating mode of the optical switch according to the optical switch control instruction, and control the output laser signal of the silicon photonic chip to enter different test channels. The optical switch control unit uses four 1*2 optical switches to realize the switching of the two optical ports of the silicon photonic chip between the extinction ratio test channel, optical power test channel 1 and optical power test channel 2. The optical signal then enters the acquisition and control unit of the chip and the gyro measurement and control module.

[0069] The signal generating unit is used to generate a sawtooth wave modulation signal for testing the phase modulator. For silicon photonic chips with integrated phase modulators, it outputs voltage signals (differential signals 1 and 2) that meet the modulation requirements of the phase modulator on the silicon photonic chip. By simulating an electrical switch, it switches to the internal phase modulator scheme and applies differential signal 1 and differential signal 2 to the signal modulation ends (Y+, Y-) of the silicon photonic chip, laying the foundation for the half-wave voltage and bandwidth test of the phase modulator part in the silicon photonic chip. If there is no integrated phase modulator on the silicon photonic chip, the test is canceled.

[0070] The signal generating unit is also used to generate a step wave signal when the gyroscope is working normally. According to the performance parameters of the silicon photonic chip, it outputs a voltage signal that meets the modulation requirements of the phase modulator on the silicon photonic chip or the modulation requirements of the external phase modulator. If the silicon photonic chip is integrated with a phase modulator, the internal phase modulator solution is selected, and the step wave signal is applied to the Y+ and Y- ports of the silicon photonic chip. If the silicon photonic chip does not have an integrated phase modulator, the external phase modulator solution is selected, and the step wave signal is applied to the Y'+ and Y'- ports of the external phase modulator. The application method of the step wave signal is automatically controlled by the control command of the analog electric switch to reduce the interference of environmental parameters caused by human intervention and ensure the consistency of the test environment.

[0071] The acquisition and control unit realizes the test and output of the splitting ratio, extinction ratio and optical power indicators of the silicon photonic chip according to the laser signals collected by different test channels; realizes the test and output of the light-free bias and saturation voltage of the silicon photonic chip according to the different outputs of the detectors on the silicon photonic chip; realizes the half-wave voltage and bandwidth test of the silicon photonic chip according to the different voltages applied to the phase modulator part of the silicon photonic chip; realizes the modulation and demodulation of the gyroscope signal, closed-loop control and communication output according to the output voltage of the detector on the silicon photonic chip.

[0072] The external light source module is used to provide stable optical power input for the receiving and modulating chip without light source and the gyroscope performance test, and is connected to the input light port of the silicon photonic chip.

[0073] The analog electric switch includes two input ports and four output ports. The two input ports are respectively connected to the chip and the gyro measurement and control module to receive the first differential signal and the second differential signal. The four output ports are divided into two groups in pairs. The first group of output ports is used to connect to the two modulation ports of the modulator of the silicon photonic chip (if the silicon photonic chip does not have an integrated modulator, the first group of output ports is vacant), and the second group of output ports is used to connect to the two modulation ports of the external phase modulator. The analog electric switch also includes an instruction control terminal, which is used to adjust the connection mode of the first group of output ports or the second group of output ports according to the analog electric switch control instruction output by the chip and the gyro measurement and control module.

[0074] The optical switches include four, the inputs of the first and second optical switches are respectively connected to the two optical ports of the silicon photonic chip, one output of the first and second optical switches are respectively connected to the inputs of the third and fourth optical switches, one output of the third and fourth optical switches are respectively connected to the two input optical ports of the external phase modulator, and the two output ports of the external phase modulator are connected to the standard optical fiber ring. Another output of the first optical switch is connected to the extinction ratio test channel, and outputs the laser signal to the chip and the gyro measurement and control module for testing the extinction ratio of the light source. Another output of the third and fourth optical switches is connected to the first and second optical power test channels, and outputs the laser signal to the chip and the gyro measurement and control module for testing the splitting ratio and optical power of the light source. Each optical switch also includes a command control terminal, which is used to receive the optical switch control command output by the chip and the gyro measurement and control module, and adjust the selection mode of each optical switch.

[0075] Different types of existing silicon photonic chips are integrated with couplers, so silicon photonic chips include two optical ports, which are two output optical ports of the coupler or two output optical ports of the modulator. When testing silicon photonic chips, the first and second input ports of the optical switch assembly of the universal test device are connected to the two optical ports of the silicon photonic chip respectively. In addition, different types of existing silicon photonic chips are integrated with detectors, and the detector output port of the silicon photonic chip connects the chip of the universal test device and the gyro measurement and control module.

[0076] Furthermore, the acquisition and control unit integrates:

[0077] The splitting ratio test unit collects lasers from optical power test channel 1 and optical power test channel 2 and calculates the splitting ratio;

[0078] The extinction ratio test unit collects the laser light of the extinction ratio test channel and calculates the extinction ratio;

[0079] The optical power test unit collects lasers from optical power test channel 1 and optical power test channel 2 and calculates the optical power;

[0080] Photocurrent processing module, used to convert the output current of PIN detector into voltage, which is used for detector performance test output and gyroscope performance test;

[0081] The differential voltage processing module is used to amplify the differential voltage output by the FET detector, which is used for detector performance test output and gyroscope performance test;

[0082] The single-ended voltage processing module is used to amplify the single-ended voltage output by the TIA detector, which is used for detector performance test output and gyroscope performance test;

[0083] The demodulation module is used to collect the output voltage of the detector using the ADC, obtain a closed-loop control digital signal by demodulating the speed signal, generate a closed-loop voltage signal through the DAC, and apply it to the modulator electrode inside the silicon photonic chip or to the external modulator electrode;

[0084] A half-wave voltage test module collects the output signal of the detector and determines the half-wave voltage of the phase modulator;

[0085] The modulation bandwidth test module collects the output signal of the detector and determines the modulation bandwidth of the phase modulator.

[0086] As another aspect of the present invention, a test instruction generation mode of a silicon photonic chip and a gyroscope performance universal test device is provided, such as Figure 2 As shown, after receiving the start test instruction, the test category is selected first, which is divided into the following two types:

[0087] 1) If it is a chip-level test instruction, the silicon photonic chip category is selected, which is specifically subdivided into: emission function (light source), detection function (detector) and modulation function (modulator). Since any coupler will be integrated in the silicon photonic chip, it is assumed that the coupler is integrated in the silicon photonic chip; for the emission function of the silicon photonic chip, the three main indicators of splitting ratio, extinction ratio and optical power are tested; for the detection function of the silicon photonic chip, the two main indicators of no-light bias and saturation voltage are tested; for the modulation function of the silicon photonic chip, the two main indicators of half-wave voltage and modulation voltage are tested; and according to the different types of detectors, they are further subdivided into PIN type, FET type and TIA type, corresponding to different silicon photonic chip test instructions.

[0088] 2) If it is a gyro-level test instruction, the detector output type is first determined, which is specifically divided into: PIN type, FET type and TIA type, which correspond to different silicon optical gyro control instructions, and mainly perform zero bias, accuracy and scale tests.

[0089] The test commands of different modes are shown in Table 1. There are a total of 16 bits, mainly including chip selection word, detector selection word, chip test category word, gyroscope test word and additional word. Among them: the chip selection word mainly gives the functional category of the current silicon photonic chip. If it has this function, the byte level is set high, otherwise it is set low; the detector selection word gives the output signal form of the detector (if any), specifically including PIN type, TIA and FET type. If it is this output form, it is set high, otherwise it is set low; the chip test category word mainly gives the category of the test chip, according to the functional category of the silicon photonic chip Different types include half-wave voltage, modulation bandwidth, saturation voltage, light-free bias, extinction ratio, splitting ratio and optical power. If the parameter needs to be tested, the level is set high, otherwise it is set low; the gyro test word mainly gives all the test categories of the silicon photonic gyroscope. According to the different gyroscope evaluation standards, it includes three types: zero bias, accuracy and scale. If the parameter needs to be tested, the level is set high, otherwise it is set low; the additional word mainly gives whether other indicators of the silicon photonic chip / gyroscope need to be tested in addition to the above 10 test indicators. If any, it can be set as a test word.

[0090] Table 1 Test instruction table for different modes

[0091]

[0092] As another aspect of the present invention, a universal testing method for silicon photonic chip performance is provided, as follows:

[0093] (1) Completely connect the optical path and circuit of the silicon photonic chip to be tested with the silicon photonic chip measurement and control module: specifically, connect the drive and temperature control ports of the silicon photonic chip to the drive and temperature control units, connect the detector of the silicon photonic chip to the power control unit, if the silicon photonic chip does not have an integrated light source, then the input optical port of the silicon photonic chip is connected to the output port of the external light source module, the modulation port of the silicon photonic chip is connected to the first group of output ports of the analog electric switch, the two output optical ports of the silicon photonic chip are connected to the optical input ports of the 1*2 optical switch 1 and the 1*2 optical switch 2, the output of the 1*2 optical switch 1 is respectively connected to the extinction ratio test port 1 and the input port of the 1*2 optical switch 3, one output of the 1*2 optical switch 2 is connected to the input port of the 1*2 optical switch 4, the output port of the 1*2 optical switch 3 is respectively connected to the optical power test port 1 and the upper port of the external phase modulator, the output port of the 1*2 optical switch 4 is respectively connected to the optical power test port 2 and the lower port of the external phase modulator, the two output ports of the external phase modulator are connected to the two input ports of the optical fiber ring, and the two modulation ports of the external phase modulator are connected to the second group of output ports of the analog electric switch.

[0094] (2) Setting the test instructions of the silicon photonic chip according to the type of silicon photonic chip to be tested and the type of detector output, transmitting the test instructions to the acquisition and control unit of the chip and the gyro measurement and control module, and the acquisition and control unit controls the operation of each unit according to the test instructions;

[0095] (3) After the chip and gyro measurement and control module receive the set test instructions, they first automatically determine the test function of the chip selection word. The specific corresponding relationship is as follows: Figure 2 As shown;

[0096] (4) Determine the emission bit of the chip selection word in the silicon photonic chip test instruction. If it is 1, it means that the silicon photonic chip has a light source unit, and the driving and temperature control unit outputs a control signal suitable for the silicon photonic chip. At this time, the light source part of the silicon photonic chip emits a stable laser, and the test is performed in accordance with steps 5, 6, and 7 in sequence;

[0097] (5) Determine the extinction ratio bit in the chip test category word. If it is 1, it means that the output extinction ratio needs to be tested. At this time, the optical switch control unit in the chip and gyro measurement and control module opens the upper port of the 1*2 optical switch 1, and the output laser enters the acquisition and control unit through the extinction ratio test channel to perform an extinction ratio test. The extinction ratio value is calculated based on the light source and the output laser, and is output through the silicon photonic chip indicator output channel;

[0098] (6) Determine the splitting ratio bit in the chip test category word. If it is 1, it means that the output splitting ratio needs to be tested. At this time, the optical switch control unit in the chip and gyro measurement and control module first opens the lower port of 1*2 optical switch 1 and the upper port of 1*2 optical switch 2, and then opens the upper port of 1*2 optical switch 3 and the lower port of 1*2 optical switch 4. The output laser enters the acquisition and control unit through the splitting ratio test channel (optical power test channel 1 and optical power test channel 2) to perform a splitting ratio test. Specifically, the splitting ratio is obtained by calculating the ratio based on the two sets of measured optical power values, and output through the silicon photonic chip indicator output channel;

[0099] (7) Determine the optical power bit in the chip test category word. If it is 1, it means that the output optical power needs to be tested. At this time, the optical switch control unit in the chip and the gyro measurement and control module first opens the lower port of the 1*2 optical switch 1 and the upper port of the 1*2 optical switch 2, and then opens the upper port of the 1*2 optical switch 3 and the lower port of the 1*2 optical switch 4. The output laser enters the acquisition and control unit through the optical power test channel (also: optical power test channel 1 and optical power test channel 2) to perform an optical power test. Specifically, the optical power is obtained by taking the sum of the two sets of measured optical power values ​​and outputting it through the silicon photonic chip indicator output channel;

[0100] (8) The detection bit of the chip selection word in the silicon photonic chip test instruction is judged. If it is 1, it means that the silicon photonic chip has a detector unit, and the power control unit outputs a power supply voltage suitable for the silicon photonic chip detector unit. At this time, the detector part of the silicon photonic chip can work stably;

[0101] (9) Determine the detector selection word in the silicon photonic chip test instruction. If the PIN bit is 1, it means that the detector output category is PIN. At this time, the output is a photocurrent signal, which enters the photocurrent processing module of the acquisition and control unit; if the TIA bit is 1, it means that the detector output category is TIA, which enters the differential voltage processing module of the acquisition and control unit; if the FET bit is 1, it means that the detector output category is FET, which enters the single-ended voltage processing module of the acquisition and control unit;

[0102] (10) The saturation voltage bit of the chip test category word in the silicon photonic chip test instruction is determined. If it is 1, it means that the detector saturation voltage needs to be tested. At this time, voltage detection is performed in the corresponding detector processing module (photocurrent processing module, differential voltage processing module and single-ended voltage processing module) according to the different detector output types. At the same time, the drive current is adjusted at a rate of 0.1 mA / s in the drive and temperature control unit until the voltage in the detector processing module reaches saturation. The saturation voltage value at this time is recorded and output through the silicon photonic chip indicator output channel;

[0103] (11) The no-light bias bit of the chip test category word in the silicon photonic chip test instruction is determined. If it is 1, it means that the detector no-light bias needs to be tested. At this time, voltage detection is performed in the corresponding detector processing module (photocurrent processing module, differential voltage processing module and single-ended voltage processing module) according to the different detector output types. At the same time, the drive current is set to 0mA in the drive and temperature control unit, and the no-light bias at this time is recorded and output through the silicon photonic chip indicator output channel;

[0104] (12) The modulation bit of the chip selection word in the silicon photonic chip test instruction is determined. If it is 1, it means that there is a modulator unit in the silicon photonic chip, and the electric switch control unit outputs an analog electric switch control instruction, so that the modulation signal generated by the signal generating unit is applied to the modulation interface Y+ and Y- of the silicon photonic chip. At this time, the light source or the external light source module on the silicon photonic chip works, and the detector is powered on. Based on the built-in light source or the external light source module, the detector on the silicon photonic chip, and the optical fiber ring, the complete gyroscope optical path is constructed;

[0105] (13) The half-wave voltage bit in the chip test category word in the silicon photonic chip test instruction is judged. If it is 1, it means that the half-wave voltage of the modulator on the silicon photonic chip needs to be tested. At this time, the signal generating unit generates a sawtooth wave signal of a certain frequency, and the detector output signal enters the half-wave voltage test module of the acquisition and control unit, and the half-wave voltage at this time is recorded and output through the silicon photonic chip indicator output channel;

[0106] (14) The modulation bandwidth bit in the chip test category word in the silicon photonic chip test instruction is determined. If it is 1, it means that the modulation bandwidth of the modulator needs to be tested. At this time, the signal generating unit generates a sine wave signal of a certain frequency, and the detector output signal enters the modulation bandwidth test module of the acquisition and control unit, and the modulation bandwidth at this time is recorded and output through the silicon photonic chip indicator output channel;

[0107] (15) The gyro test word in the silicon photonic chip test instruction is judged. If it is 1, it means that a gyro level test needs to be performed on the silicon photonic chip. At this time, there are only two possibilities: one is that the silicon photonic chip does not contain a modulator, and the other is that it contains a modulator;

[0108] (16) The modulation bit in the chip selection word is judged. If it is 1, it means that there is a modulator. At this time, the signal generation unit generates a modulation signal, and the electrical switch control unit controls the 2*4 analog electrical switch to select the Y+ / Y- modulation pin inside the silicon photonic chip. At the same time, the optical switch control instruction sequentially selects the lower port of 1*2 optical switch 1 and the upper port of 1*2 optical switch 2, and continues to select the lower port of 1*2 optical switch 3 and the upper port of 1*2 optical switch 4. At this time, no modulation signal is applied to the modulation electrode of the external phase modulator, and it directly enters the optical fiber loop, thereby realizing the gyro optical path closed loop;

[0109] (17) The gyro processing procedure under the condition that the silicon photonic chip contains a modulator is as follows: First, the gyro test type word is determined, which mainly includes three indicators: zero bias, accuracy and scale. If the position is 1, the test of this item needs to be performed; secondly, the detector type is determined, which mainly includes PIN type, FET type and TIA type; at this time, based on the built-in light source of the silicon photonic chip or the external light source module, the detector on the silicon photonic chip, and the optical fiber ring, the complete gyro optical path is constructed.

[0110] 1) If it is a PIN type output, it directly enters the current processing module in the acquisition and control unit in the measurement and control module. The current processing module mainly realizes the conversion of the detector photocurrent to voltage, and then undergoes single-ended voltage amplification to meet the AD input voltage range, and then enters the ADC for voltage sampling. The required closed-loop control digital signal is obtained by demodulating the speed signal, and then a closed-loop voltage signal is generated through the DAC and applied to the modulator electrode inside the silicon photonic chip. Then, the three indicators of zero bias, accuracy and scale are tested according to the test type word;

[0111] 2) If it is a FET type output, it directly enters the single-ended voltage processing module in the acquisition and control unit in the measurement and control module. The single-ended voltage processing module mainly realizes single-ended voltage amplification to meet the AD input voltage range, and then enters the ADC for voltage sampling. The required closed-loop control digital signal is obtained by demodulating the speed signal, and then a closed-loop voltage signal is generated through the DAC and applied to the modulator electrode inside the silicon photonic chip. Then, the zero bias, accuracy and scale are tested according to the test type word;

[0112] 3) If it is a TIA type output, it directly enters the differential voltage processing module in the acquisition and control unit in the measurement and control module. The differential voltage processing module mainly realizes voltage differential amplification to meet the AD input voltage range, and then enters the ADC for voltage sampling. The required closed-loop control digital signal is obtained by demodulating the speed signal, and then a closed-loop voltage signal is generated through the DAC and applied to the modulator electrode inside the silicon photonic chip. Then, the zero bias, accuracy and scale are tested according to the test type word;

[0113] (18) The modulation bit in the chip selection word is determined. If it is 0, it means that there is no modulator. At this time, the signal generating unit generates a modulation signal, and the electrical switch control unit controls the 2*4 analog electrical switch to select the external phase modulator, specifically applied to the Y'+ / Y'- modulation pin. At the same time, the optical switch control instruction sequentially selects the lower port of the 1*2 optical switch 1 and the upper port of the 1*2 optical switch 2, and continues to select the lower port of the 1*2 optical switch 3 and the upper port of the 1*2 optical switch 4. At this time, the modulation signal is applied to the modulation electrode of the external phase modulator, and then enters the optical fiber ring after modulation, thereby realizing the gyro optical path closed loop;

[0114] (19) When the silicon photonic chip does not contain a modulator and an external modulator must be used, the gyro processing procedure is as follows: First, the gyro test type word is determined, which mainly includes three indicators: zero bias, accuracy, and scale. If this bit is 1, this item test needs to be performed; secondly, the detector type is determined, which mainly includes PIN type, FET type, and TIA type; at this time, the complete gyro optical path is constructed based on the built-in light source or external light source module, the detector on the silicon photonic chip, the external phase modulator, and the optical fiber ring;

[0115] 1) If it is a PIN type output, it directly enters the current processing module in the acquisition and control unit in the measurement and control module. The current processing module mainly realizes the conversion of the detector photocurrent to voltage, and then undergoes single-ended voltage amplification to meet the AD input voltage range, and then enters the ADC for voltage sampling. The required closed-loop control digital signal is obtained by demodulating the speed signal, and then a closed-loop voltage signal is generated through the DAC and applied to the external modulator electrode. Then, the zero bias, accuracy and scale three indicators are tested according to the test type word;

[0116] 2) If it is a FET type output, it directly enters the single-ended voltage processing module in the acquisition and control unit in the measurement and control module. The single-ended voltage processing module mainly realizes single-ended voltage amplification to meet the AD input voltage range, and then enters the ADC for voltage sampling. The required closed-loop control digital signal is obtained by demodulating the speed signal, and then a closed-loop voltage signal is generated through the DAC and applied to the external modulator electrode. Then, the zero bias, accuracy and scale are tested according to the test type word;

[0117] 3) If it is a TIA type output, it directly enters the differential voltage processing module in the acquisition and control unit in the measurement and control module. The differential voltage processing module mainly realizes voltage differential amplification to meet the AD input voltage range, and then enters the ADC for voltage sampling. The required closed-loop control digital signal is obtained by demodulating the speed signal, and then a closed-loop voltage signal is generated through the DAC and applied to the external modulator electrode. Then, the zero bias, accuracy and scale are tested according to the test type.

[0118] (20) The additional bit in the additional test word of the silicon photonic chip is judged. If it is 0, it means that there is no need to test other parameter indicators of the silicon photonic chip and the gyroscope. If it is 1, according to the self-set test instructions, it enters the corresponding test module of the acquisition and control unit, and outputs the test value through the silicon photonic chip indicator output channel.

[0119] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or used in place of features in other embodiments.

[0120] It should be emphasized that the term "include / comprises" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0121] The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended that the embodiments of the invention be limited to the exact construction and operation illustrated and described, but rather all suitable modifications and equivalents falling within the scope thereof are intended to be covered.

[0122] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0123] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A universal testing device for silicon photonic chips and gyroscope performance, characterized in that: include: The chip and gyro measurement and control module include the following units: Driving and temperature control unit, used for constant current driving and temperature control of light sources on silicon photonic chips; A power control unit, used to power detectors on silicon photonic chips; An electric switch control unit, used to control the gating mode of the analog electric switch according to the analog electric switch control instruction, and apply the modulation signal output by the signal generating unit to the phase modulator in the silicon photonic chip or to the external phase modulator; An optical switch control unit, used to control the gating mode of the optical switch according to the optical switch control instruction, and control the silicon photonic chip to output laser signals into different test channels; A signal generating unit, used to generate a modulation signal for testing the phase modulator and a modulation signal for the gyroscope to work normally; The acquisition and control unit is used to control the operation of each unit and collect test signals to perform silicon photonic chip and gyroscope performance tests; A light source module is used to provide a stable optical power input to a silicon photonic chip without a light source and is connected to an input optical port of the silicon photonic chip; An analog electric switch, wherein the input end of the analog electric switch is connected to the electric switch control unit, and the output end includes two channels, which are respectively connected to the modulation port of the phase modulator on the silicon photonic chip and the modulation port of the external phase modulator; The optical switches include four optical switches, wherein the inputs of the first and second optical switches are respectively connected to the two optical ports of the silicon photonic chip, the two outputs of the first optical switch are respectively connected to the extinction ratio test channel and the input of the third optical switch, one output of the second optical switch is connected to the input of the fourth optical switch, the two outputs of the third optical switch are respectively connected to the first optical power test channel and the first port of the external phase modulator, and the two outputs of the fourth optical switch are respectively connected to the second optical power test channel and the second port of the external phase modulator; The output end of the external phase modulator is connected to the optical fiber ring.

2. The universal testing device according to claim 1, characterized in that: The analog electric switch also includes an instruction control terminal, which is used to switch the connection mode of the modulation port according to the analog electric switch control instruction output by the chip and the gyro measurement and control module; Each optical switch also includes an instruction control terminal for receiving an optical switch control instruction output by the chip and the gyro measurement and control module, and adjusting the gating mode of each optical switch.

3. The universal testing device according to claim 1, characterized in that: The acquisition and control unit comprises: A splitting ratio test unit, used for collecting the output lasers of the first and second optical power test channels and calculating the splitting ratio; An extinction ratio test unit is used to collect the output laser of the extinction ratio test channel and calculate the extinction ratio; An optical power test unit, used for collecting the output lasers of the first and second optical power test channels and calculating the optical power; A photocurrent processing module, used to convert the photocurrent output by the PIN detector into a voltage; A differential voltage processing module, used for amplifying the differential voltage output by the FET type detector; A single-ended voltage processing module is used to amplify the single-ended voltage output by the TIA type detector; The demodulation module is used to collect the detector output signal, obtain the closed-loop control digital signal by demodulating the speed signal, generate a closed-loop voltage signal, and apply it to the phase modulator inside the silicon photonic chip or to an external phase modulator; A half-wave voltage test module is used to collect the output signal of the detector and determine the half-wave voltage of the phase modulator; The modulation bandwidth test module is used to collect the output signal of the detector and determine the modulation bandwidth of the phase modulator.

4. The universal testing device according to claim 1, characterized in that: The test instructions of the universal testing device include chip selection words, detector selection words, chip test category words, and gyroscope test words. The chip selection words include emission bits, detection bits, and modulation bits. The detector selection words include PIN bits, TIA bits, and FET bits. The chip test category words include half-wave voltage bits, modulation bandwidth bits, saturation voltage bits, lightless bias bits, extinction ratio bits, splitting ratio bits, and optical power bits. The gyroscope test words include zero bias bits, precision bits, and scale bits.

5. The universal testing device according to claim 4, characterized in that: The test instruction also includes additional words, and the additional words are used to increase the test index.

6. A universal testing method for silicon photonic chips and gyroscope performance, characterized in that: The steps include: S1, connect the silicon photonic chip to be tested to a universal testing device, receive a test instruction, if it includes silicon photonic chip testing, go to step S2, if it includes gyroscope testing, go to step S6; S2, determine the type of silicon photonic chip, if the silicon photonic chip includes a light source, proceed to step S3, if the silicon photonic chip includes a detector, proceed to step S4, if the silicon photonic chip includes a phase modulator, proceed to step S5; S3, the light source works and the test category of the silicon photonic chip is read; If it is determined that the test category includes an extinction ratio test, the extinction ratio test channel of the first optical switch is controlled to be connected, the output laser is collected, and the extinction ratio is calculated; If it is determined that the test category includes a splitting ratio test, the first and second optical power test channels of the optical switch are controlled to be connected, the output laser is collected, and the splitting ratio is calculated; If it is determined that the test category includes an optical power test, the first and second optical power test channels of the optical switch are controlled to be connected, the output laser is collected, and the optical power is calculated; S4, the detector works and reads the test category of the silicon photonic chip; If the test category includes a saturation voltage test, the drive current is controlled to change at a set rate until the voltage reaches saturation, and the saturation voltage value is recorded; If the test category includes a no-light bias test, the drive current is set to 0 and the no-light bias value is recorded; S5, configure the light source on the silicon photonic chip or the external light source module, the silicon photonic chip and the optical fiber ring to work, form a gyro optical path, simulate the electric switch to control the modulation signal to be applied to the silicon photonic chip phase modulator, and read the test category of the silicon photonic chip; If it is determined that the test category includes a half-wave voltage test, the signal generating unit generates a sawtooth wave signal of a set frequency, collects the detector output signal, and records the half-wave voltage; If it is determined that the test category includes a modulation bandwidth test, the signal generating unit generates a sine wave signal of a set frequency, collects the detector output signal, and records the modulation bandwidth; S6, determining whether the silicon photonic chip is integrated with a phase modulator, if yes, proceeding to step S7, otherwise proceeding to step S9; S7, the phase modulator works, the analog electric switch controls the modulation signal to be applied to the phase modulator of the silicon photonic chip, the optical switch is controlled to be connected with the channel of the external phase modulator and the optical fiber ring, no modulation signal is applied to the external phase modulator, the light source on the silicon photonic chip or the external light source module, the silicon photonic chip and the optical fiber ring work, and form the gyroscope optical path; S8, collecting the detector output signal, outputting a closed-loop voltage signal through voltage sampling and speed demodulation, applying it to the silicon photonic chip phase modulator, and performing a test according to the test category; S9, controlling the optical switch to communicate with the channel of the external phase modulator and the optical fiber loop, applying the analog electrical switch to control the modulation signal to the external phase modulator, and making the light source on the silicon photonic chip or the external light source module, the silicon photonic chip, the external phase modulator, and the optical fiber loop work to form a gyroscope optical path; S10, collecting the detector output signal, outputting a closed-loop voltage signal through voltage sampling and speed demodulation, applying it to an external phase modulator, and performing a test according to the test category.

7. The universal testing method according to claim 6, characterized in that: The test instruction includes a chip selection word, a detector selection word, a chip test category word, and a gyroscope test word. The chip selection word includes an emission bit, a detection bit, and a modulation bit. The detector selection word includes a PIN bit, a TIA bit, and a FET bit. The chip test category word includes a half-wave voltage bit, a modulation bandwidth bit, a saturation voltage bit, a lightless bias bit, an extinction ratio bit, a splitting ratio bit, and an optical power bit. The gyroscope test word includes a zero bias bit, an accuracy bit, and a scale bit.

8. The universal testing device according to claim 7, characterized in that: The test instruction also includes additional words, and the additional words are used to increase the test index.

9. The method according to any one of claims 6 to 8, characterized in that: The detector is of PIN type, FET type, or TIA type. The universal testing method also includes the steps of determining the detector type, and processing the output signal according to the detector type to obtain an output voltage that meets the sampling voltage requirements.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: The processor executes the computer program to implement the method described in any one of claims 6 to 9.

Images