A lossless calibration method for optical switch control voltage in optical switch switching delay chip

Abstract

The application discloses a lossless calibration method for switching delay chip of an optical switch, and comprises a multi-channel voltage output module, an optical power detection module and a single-chip microcomputer module to form a calibration and control system of the switching delay chip of the optical switch. n The method can obtain the maximum output extinction ratio of each optical switch at the last port by iteratively optimizing the control voltage of all optical switches in the switching delay chip of the optical switch. With the increase of the iteration number, the output extinction ratio will continuously increase to the preset range and remain stable, and finally the control voltage of the "straight-through" and "crossing" states of each optical switch in the switching delay chip of the optical switch is obtained. The application realizes the automatic, simple and lossless calibration of the control voltage of each stage optical switch in the switching delay chip of the optical switch by iteration optimization without introducing additional optical devices.

Description

Technical Field

[0001] This invention relates to a non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip, belonging to the fields of optical communication and microwave photonics technology. Background Technology

[0002] In phased array radar systems, true time delay technology has proven to be an effective means of solving the "beam squint" problem. Compared with traditional electrical true time delay technology, optical true time delay technology using optical waveguides has advantages such as low loss, large bandwidth, and resistance to electromagnetic interference, and is considered one of the key technologies for future radar systems. As an important optical device in the fields of optical communication and microwave photonics, optical switch-type delay chips can achieve stable and adjustable optical true time delay, and have been widely used in microwave photonic beamforming systems in recent years, and are developing towards integration.

[0003] Optical switch delay chips are optical devices composed of a series of Mach-Zehnder interferometer-based optical switches connected to multi-stage delay waveguides. Adjustable optical true delay can be achieved by controlling the states of the optical switches to change the transmission path of the optical signal. Due to manufacturing errors, the initial state of the optical switches is unknown, requiring calibration of the "through" and "crossover" state voltages of each stage of the optical switch on the optical switch delay chip. Currently reported literature proposes three calibration schemes: adding a directional coupler after each optical switch as an optical power monitoring port for calibration; adding a variable attenuator after each optical switch to control the transmission path of the optical signal for calibration; and adding an additional phase modulator after each optical switch for indirect calibration. However, adding additional monitoring ports, variable attenuators, phase modulators, etc., after each optical switch increases the insertion loss and complexity of the optical switch delay chip. Therefore, a simple, lossless, and automated optical switch state calibration scheme is urgently needed. Summary of the Invention

[0004] Technical Problem: To address the issues of existing optical switch calibration methods in optical switch switching delay chips, which require numerous optical and electrical I / O interfaces and increase chip insertion loss and complexity, this invention proposes a simple, non-destructive calibration method based on iterative optimization. This method automatically calibrates the control voltage of the optical switch in the optical switch switching delay chip and outputs the specified delay state without introducing additional optical components.

[0005] Technical Solution: To solve the above-mentioned technical problems, this invention proposes a non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip. The method includes the following steps:

[0006] (1) Set up an optical switch switching delay chip, which has n optical switches inside, namely S1 to S2. n n optical switches S1 to Sn Connect n-1 delay lines at intervals, denoted as L1 to L2. n-1 Furthermore, the input port In0 of the optical switch switching delay chip is connected to the laser, and the output port Out0 is connected to the optical power detection module. The multi-channel voltage output module is connected to the optical switches S1 to S2. n The voltage control port is connected, the microcontroller module is connected to the multi-channel voltage output module and the optical power detection module respectively, and the computer is connected to the microcontroller module via a serial port;

[0007] (2) A laser beam is input into the optical switch delay chip. Voltage scanning starts from the first optical switch S1. The multi-channel voltage output module is controlled to apply a step-by-step driving voltage to it. The optical power detection module tests the optical power of the optical switch switching delay chip Out0 port in real time, obtains the voltage-optical power relationship graph, and calculates the output extinction ratio obtained by the optical switch at the Out0 port. After the optical switch S1 is scanned, a control voltage corresponding to the extreme point in the voltage-optical power relationship graph is applied to it. Then, the control voltage value is kept unchanged, and voltage scanning is performed on the next optical switch. The process of calculating the output extinction ratio and applying the control voltage is repeated until all optical switches have been scanned.

[0008] (3) For each optical switch S1 to S2 n The control voltage corresponding to the extreme point of the voltage-optical power relationship graph of each optical switch in the previous round is randomly selected, and the control voltage corresponding to each optical switch is applied to the optical switch. Starting from the first optical switch, the next round of voltage scanning is performed on all optical switches, and the process of calculating the output extinction ratio and applying the control voltage is repeated. After each round of voltage scanning, the output extinction ratio obtained by each optical switch at the Out0 port is added as the judgment condition for the end of the iteration. When the sum of the output extinction ratios of each optical switch reaches the predetermined range and remains stable, the iteration stops; otherwise, the next round of iteration continues. After the iteration ends, the control voltage corresponding to the extreme point of the voltage-optical power relationship graph obtained in the last round of scanning is used as the "through" or "cross" voltage of each optical switch.

[0009] (4) Connect the output port Out0 of the optical switch delay chip to the delay test system, and use the optical vector network analysis method to test the absolute delay of the optical signal through the optical switch to switch the delay chip, and distinguish the "straight-through" and "cross-through" states corresponding to the two control voltages of each optical switch.

[0010] Furthermore, in step (1), the multi-channel voltage output module converts the digital signal output by the microcontroller module into an analog-to-digital converter and amplifies the signal before outputting the voltage to the voltage control port of each optical switch in the optical switch switching delay chip; the optical power detection module converts the optical signal output by the optical switch switching delay chip into an optical signal, amplifies it through transimpedance and converts it into an analog-to-digital converter before transmitting it to the microcontroller module to realize real-time detection of optical power; the computer module connects to the microcontroller module through a serial port to control the entire system to work collaboratively and automatically.

[0011] Furthermore, in step (2), a driving voltage of 0 to 10V in 0.02V increments is applied.

[0012] Furthermore, the method for calculating the output extinction ratio in step (2) is as follows:

[0013] A preset range of step drive voltage is applied to the modulation arm of the first optical switch S1 in the optical switch switching delay chip, and the power value output by the Out0 port is detected in real time. The one-to-one correspondence between the drive voltage and the optical power output by the Out0 port is obtained and a voltage-optical power relationship graph is plotted. After the first optical switch is scanned, the two extreme points corresponding to the maximum and minimum optical power values ​​are obtained from the relationship graph. These correspond to different states of the optical switch S1. The difference between the maximum and minimum optical power values ​​is the output extinction ratio of the first optical switch.

[0014] Furthermore, in step (3), after each iteration scan completes all optical switches, the sum of the output extinction ratios obtained by each optical switch at the Out0 port is used as the judgment condition for the end of the iteration. If the change in the sum of the output extinction ratios obtained by each optical switch at the Out0 port in the two iterations before and after is less than 2dB, the iteration stops. At this time, the output extinction ratios of each optical switch in the optical switch switching delay chip have reached the preset range and remain stable, and the control voltage has converged to the "through" or "cross" voltage of each optical switch.

[0015] Furthermore, in step (4), the method for distinguishing the "straight-through" and "cross-through" states corresponding to the two control voltages of each optical switch is as follows:

[0016] (4.1) Each optical switch receives a pair of voltages that put it in a "straight-through" or "cross-through" state. Optical switches S1 to S2 n There are 2 n There are different combinations of voltage values, each of which corresponds to a transmission path of the optical signal in the optical switch switching delay chip;

[0017] (4.2) Input a laser beam of a defined wavelength into the In0 port of the optical switch switching delay chip, and apply 2... nFor any combination of different voltage values, test the delay of the optical switch switching delay chip under different control voltages from the Out0 port. If there is an optical signal output from the Out0 port, record the delay of optical switches S1 to S2 at this time. n The control voltage value and the measured delay are compared. If there is no optical signal output from the Out0 port, it proves that the optical signal is output from the Out1 port. At this time, the other control voltage value of the two control voltages is applied to the optical switch S1 to make the optical signal output from the Out0 port. Record the values ​​of optical switches S1 to S2. n The control voltage value and the measured delay;

[0018] (4.3) The delay amount of each transmission path is a pre-designed fixed value. Based on the delay amount obtained by the test, the transmission path of the optical signal in the optical switch switching delay chip is determined, thereby determining the "straight-through" and "cross-through" states corresponding to the two control voltages of the optical switch.

[0019] Furthermore, the optical transmission medium of the optical switch switching delay chip is not limited to silicon.

[0020] Furthermore, the optical switch is not limited to the MZI type 4-port structure.

[0021] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0022] The technical solution of this invention is based on iterative optimization of the control voltage of the optical switch to obtain the maximum output extinction ratio of the optical switch. Without the introduction of additional optical components, it realizes the automatic calibration of the control voltage of the optical switch in the optical switch switching delay chip, effectively reducing the complexity and cost of calibration. At the same time, it avoids the introduction of additional optical components into the optical switch switching delay chip, reduces the number of optical and electrical I / O ports of the chip, thereby reducing the insertion loss and packaging difficulty of the optical switch switching delay chip. Attached Figure Description

[0023] Figure 1 This is a test system diagram for automatically calibrating the control voltage of each stage of the optical switch in the optical switch switching delay chip provided by the present invention.

[0024] Figure 2 This is a schematic diagram of a 5-bit optical switch switching delay chip structure.

[0025] Figure 3 This is a schematic diagram of a 2×2MZI optical switch structure and its "straight-through" and "cross-through" states.

[0026] Figure 4 A flowchart illustrating the optical switch control voltage calibration method in the optical switch switching delay chip provided by this invention.

[0027] Figure 5 The voltage-optical power relationship obtained by optical switch S1 during the first and second scans is shown in the graph.

[0028] Figure 6 This is a graph showing the relationship between the sum of extinction ratios obtained by each optical switch at the chip's output port and the number of iterations.

[0029] Figure 7 The transmission path of the optical signal in the chip is the one with the minimum absolute delay.

[0030] Figure 8 This is the transmission spectrum of the chip under minimum delay after two iterative scans.

[0031] Figure 9 This is the transmission spectrum of the chip under minimum delay after 8 iterative scans.

[0032] Figure 10 This is the transmission spectrum of the chip under minimum delay after 15 iterative scans.

[0033] Figure 11 The step delay is measured by two methods: optical power monitoring port calibration and iterative optimization calibration. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, taking a 5-bit optical switch switching delay chip as an example.

[0035] Figure 1 This invention provides a test system diagram for automatically calibrating the control voltages of each stage of an optical switch in a switching delay chip based on iterative optimization. During the calibration of the six off-switch control voltages of the 5-bit optical switch switching delay chip, a laser is connected to the In0 port of the chip; an optical power detection module is connected to the Out0 port of the chip for real-time optical power detection; a multi-channel voltage output module is connected to the electrodes on the modulation arms of the S1-S6 optical switches; and a computer and a microcontroller are connected via a serial port to control the coordinated and automated operation of each module. A laser output signal with a power of 7dBm and a wavelength of 1560nm is set and input to the In0 port of the optical switch switching delay chip after passing through a polarization controller. The host computer program controls the system to automatically iteratively scan the optical switches in the chip. As the number of iterations increases, the output extinction ratio obtained by each optical switch at the Out0 port gradually increases to a predetermined range and remains stable, ultimately obtaining the control voltage for each optical switch in either a "straight-through" or "crossover" state.

[0036] Figure 2A schematic diagram of a 5-bit optical switch delay chip is shown, which consists of six cascaded 2×2 MZI thermo-optic switches (S1~S6) and five pairs of optical delay waveguides with different length differences. The chip was fabricated using the SOI integrated photonics fabrication platform provided by the Institute of Microelectronics, Chinese Academy of Sciences. The waveguides are constructed using 450nm×220nm rectangular optical waveguides to form the MZI structure, with both the MZI arm length and the heating electrode length being 200μm. The 2×2 MZI thermo-optic switch structure is shown below. Figure 3 As shown in (a), the structure consists of two 2×2 multimode interference couplers connected to two straight waveguides of equal length. One straight waveguide serves as the reference arm; the other straight waveguide serves as the modulation arm, with a heating electrode added above it to modulate the phase of the optical path. After heating the modulation arm, due to the different phase difference between the upper and lower arms, the optical signal at the output end will undergo destructive or constructive interference, thereby controlling the optical power output at the two output ends of the optical switch and realizing the selection of the "straight-through" and "cross-through" states of the optical path, such as... Figure 3 As shown in (b). Each optical switch has 4 ports, namely E in0 E in1 E out0 E out1 The optical signal comes from E in0 To E out0 Transmission, from E in1 To E out1 The transmission is in "pass-through" mode; from E in0 To E out1 Transmission, from E in1 To E out0 The transmission is in "cross" mode.

[0037] This invention proposes a simple, automatic, and non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip. The calibration flowchart of this method is shown below. Figure 4 As shown. During the calibration process, the Out0 port of the chip is used as the optical power monitoring port. The driving voltage on each modulation arm of the optical switch in the optical switch switching delay chip is scanned multiple times in stages. Based on the voltage-optical power relationship obtained by scanning each optical switch at the Out0 port, the control voltage corresponding to the optical power extreme point is applied. For example, in the first round of scanning, a step control voltage is applied to optical switch S1 to obtain the corresponding voltage-optical power relationship as shown. Figure 5As shown in (a), after obtaining the control voltages V1 and V2 corresponding to their extreme points, one of the control voltage values ​​V1 is applied to S1. This voltage value is then kept constant, and the voltage scanning and control voltage application operations are repeated for optical switches S2 to S6. After the first round of scanning is completed, the control voltage corresponding to the extreme point in the voltage-optical power relationship graph obtained from each optical switch scan will be applied to the modulation arm of all optical switches. At this time, compared to the initial state, the voltage applied to the optical switch switching delay chip will cause the optical signal within the chip to be transmitted step-by-step with a larger splitting ratio, thereby reducing interference at the Out0 port. During the next round of optical switch drive voltage scanning, each optical switch will obtain a larger output extinction ratio at the Out0 port. The voltage-optical power relationship graph corresponding to optical switch S1 in the second round of scanning is shown below. Figure 5 As shown in (b), the output extinction ratio shows a significant increase. Similarly, after a certain number of iterative scans, when the optical switch switching delay chip achieves the maximum output extinction ratio at the Out0 port under a set of control voltages, it proves that the optical switch achieves the best optical path switching effect under that set of voltages. At this point, V1 and V2 obtained by scanning the Out0 port of each optical switch are the "through" and "cross" voltages. The process of continuously scanning the driving voltage of each optical switch to achieve a larger output extinction ratio at the Out0 port until the extinction ratio stabilizes is also the process of the control voltage continuously approaching the "through" and "cross" voltages of each optical switch. Based on the above principle, we can iteratively scan each optical switch on the optical switch switching delay chip to achieve an increase and stabilization of the output extinction ratio at the Out0 port, thereby obtaining the control voltages for the "through" and "cross" states of all optical switches.

[0038] The relationship between the sum of the output extinction ratios obtained by each optical switch at the Out0 port and the number of iterations is as follows: Figure 6 As shown in Table 1, it can be seen from the experimental data and fitting curves that as the number of iterations increases, the sum of extinction ratios gradually increases and tends to stabilize. Here, a set of control voltages of each optical switch obtained after 15 iterations is taken as the voltages of the "straight-through" or "cross-through" states of the optical switches.

[0039] Control voltage V1 4.82V 1.34V 5.58V 5.30V 1.78V 4.68V Control voltage V2 7.56V 5.50V 8.26V 7.66V 5.66V 7.12V

[0040] Table 1 shows the control voltages for the "straight-through" or "cross-through" states of each level of optical switch.

[0041] At this point, each optical switch receives a pair of voltages that put it in either a "straight-through" or "cross-through" state, but it is still impossible to correlate the two control voltages with the "straight-through" or "cross-through" state of the optical switch. Next, optical vector network analysis is used to measure the absolute delay of the light to distinguish the two voltages. There are a total of 2 optical switches S1 to S6. 6Different voltage combinations correspond to different transmission paths of the optical signal in the optical switch switching delay chip. Therefore, based on the different delay amounts corresponding to different voltage combinations, the "straight-through" and "cross-through" states corresponding to the two control voltages can be distinguished. A laser beam of a specific wavelength is input to the In0 port of the optical switch switching delay chip, and the delay amount of the optical switch switching delay chip under different control voltages is tested from the Out0 port. The test results show that when the absolute delay amount is minimum, the voltages applied to optical switches S1 to S6 are 7.56V, 5.50V, 5.58V, 5.30V, 5.66V, and 7.12V, respectively. (The last sentence appears to be incomplete and possibly refers to a different optical switch switching delay chip.) Figure 2 As shown in the schematic diagram, when optical switches S1 to S6 are in the "cross", "straight", "straight", "straight", "straight", and "cross" states, the delay of the optical signal input to the chip is minimized. Figure 7 As shown in Table 2, the two control voltages of each optical switch in Table 1 can be correlated with the "straight-through" or "cross-through" state of the optical switch.

[0042] "Straight-through" voltage 4.82V 5.50V 5.58V 5.30V 5.66V 4.68V "Cross" voltage 7.56V 1.34V 8.26V 7.66V 1.78V 7.12V

[0043] Table 2 shows the voltages corresponding to the "straight-through" and "cross-through" states of each level of optical switch.

[0044] Next, the accuracy of the control voltage obtained from the optical switch in the optical switch delay chip was tested based on iterative optimization calibration. As is well known, when the control voltage of the optical switch in the "straight-through" and "cross-over" states is inaccurate, interference fringes will appear in the output spectra of both Out1 and Out2 of the optical switch switching delay chip. Based on this, the transmission spectrum of the optical switch switching delay chip in the minimum delay state was tested under different iteration numbers. Figures 8-10 The transmission spectra of the optical switch switching delay chip under the minimum delay state after 2, 8, and 15 iterations are shown respectively. The test results show that the interference of the transmission spectrum decreases significantly with increasing iteration count, proving the effectiveness of the calibration method. Furthermore, after 15 iterations, the jitter in the transmission spectrum near 1560 nm is less than 1.5 dB, indicating that all optical switches in the optical switch switching delay chip have achieved ideal control. The residual spectral jitter may be caused by insufficient extinction ratio of the optical switches themselves and interference from the grating coupler.

[0045] Next, the monitoring waveguide was used to calibrate each optical switch on the optical switch switching delay chip. The 32 delay states of the optical switch switching delay chip were then tested using both the optical switch control voltage obtained from the monitoring waveguide calibration and the voltage obtained from the iterative optimization calibration. Figure 11 (a) Calibration using a monitoring waveguide Figure 11(b) Based on iterative optimization calibration, the delay steps measured by the two methods are 3.076ps / step and 3.088ps / step, respectively, with a difference of only 0.39%, which is a good match.

[0046] Moreover, the technical solution of the present invention obtains the maximum output extinction ratio of the optical switch based on iterative optimization of the control voltage of the optical switch. Without the introduction of additional optical components, it realizes the automatic calibration of the control voltage of the optical switch in the optical switch switching delay chip, effectively reducing the complexity and cost of calibration. At the same time, it avoids the introduction of additional optical components into the optical switch switching delay chip, reduces the number of optical and electrical I / O ports of the chip, thereby reducing the insertion loss and packaging difficulty of the optical switch switching delay chip.

[0047] The specific implementation methods described above further illustrate the purpose and technical solution of this invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made without departing from the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip, characterized in that, Includes the following steps: (1) Set up an optical switch switching delay chip, which has n optical switches inside, namely S1 to S2. n n optical switches S1 to S2 n Connect n-1 delay lines at intervals, denoted as L1 to L2. n-1 Furthermore, the input port In0 of the optical switch switching delay chip is connected to the laser, and the output port Out0 is connected to the optical power detection module. The multi-channel voltage output module is connected to the optical switches S1 to S2. n The voltage control port is connected, the microcontroller module is connected to the multi-channel voltage output module and the optical power detection module respectively, and the computer is connected to the microcontroller module via a serial port; (2) A laser beam is input into the optical switch delay chip. Voltage scanning starts from the first optical switch S1. The multi-channel voltage output module is controlled to apply a step-by-step driving voltage to it. The optical power detection module tests the optical power of the optical switch switching delay chip Out0 port in real time, obtains the voltage-optical power relationship graph, and calculates the output extinction ratio obtained by the optical switch at the Out0 port. After the optical switch S1 is scanned, a control voltage corresponding to the extreme point in the voltage-optical power relationship graph is applied to it. Then, the control voltage value is kept unchanged, and voltage scanning is performed on the next optical switch. The process of calculating the output extinction ratio and applying the control voltage is repeated until all optical switches have been scanned. (3) For each optical switch S1 to S2 n The control voltage corresponding to the extreme point of the voltage-optical power relationship graph of each optical switch in the previous round is randomly selected, and the control voltage corresponding to each optical switch is applied to the optical switch. Starting from the first optical switch, the next round of voltage scanning is performed on all optical switches, and the process of calculating the output extinction ratio and applying the control voltage is repeated. After each round of voltage scanning, the output extinction ratios obtained by each optical switch at the Out0 port are added together as the judgment condition for the end of the iteration. When the sum of the output extinction ratios of each optical switch reaches the predetermined range and remains stable, the iteration stops; otherwise, the next round of iteration continues. After the iteration ends, the control voltage corresponding to the extreme point of the voltage-optical power relationship graph obtained in the last round of scanning is used as the "through" or "cross" voltage of each optical switch. (4) Connect the output port Out0 of the optical switch delay chip to the delay test system, and use the optical vector network analysis method to test the absolute delay of the optical signal through the optical switch to switch the delay chip, and distinguish the "straight-through" and "cross-through" states corresponding to the two control voltages of each optical switch.

2. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, In step (1), the multi-channel voltage output module converts the digital signal output by the microcontroller module into an analog-to-digital converter and amplifies the signal before outputting the voltage to the voltage control port of each optical switch in the optical switch switching delay chip; the optical power detection module converts the optical signal output by the optical switch switching delay chip into an optical signal, amplifies it through transimpedance and converts it into an analog-to-digital converter before transmitting it to the microcontroller module to realize real-time detection of optical power; the computer module connects to the microcontroller module through a serial port to control the entire system to work collaboratively and automatically.

3. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, In step (2), a driving voltage of 0 to 10V in 0.02V increments is applied.

4. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, The method for calculating the output extinction ratio in step (2) is as follows: A preset range of step drive voltage is applied to the modulation arm of the first optical switch S1 in the optical switch switching delay chip, and the power value output by the Out0 port is detected in real time. The one-to-one correspondence between the drive voltage and the optical power output by the Out0 port is obtained and a voltage-optical power relationship graph is plotted. After the first optical switch is scanned, the two extreme points corresponding to the maximum and minimum optical power values ​​are obtained from the relationship graph. These correspond to different states of the optical switch S1. The difference between the maximum and minimum optical power values ​​is the output extinction ratio of the first optical switch.

5. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, In step (3), after each iteration scan completes all optical switches, the sum of the output extinction ratios obtained by each optical switch at the Out0 port is used as the judgment condition for the end of the iteration. If the change in the sum of the output extinction ratios obtained by each optical switch at the Out0 port in the two iterations before and after is less than 2dB, the iteration stops. At this time, the output extinction ratios of each optical switch in the optical switch switching delay chip have reached the preset range and remain stable, and the control voltage has converged to the "through" or "cross" voltage of each optical switch.

6. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, In step (4), the method for distinguishing the "straight-through" and "cross-through" states corresponding to the two control voltages of each optical switch is as follows: (4.1) Each optical switch receives a pair of voltages that put it in a "straight-through" or "cross-through" state. Optical switches S1 to S2 n There are 2 n There are different combinations of voltage values, each of which corresponds to a transmission path of the optical signal in the optical switch switching delay chip; (4.2) Input a laser beam of a defined wavelength into the In0 port of the optical switch switching delay chip, and apply 2... n For any combination of different voltage values, test the delay of the optical switch switching delay chip under different control voltages from the Out0 port. If there is an optical signal output from the Out0 port, record the delay of optical switches S1 to S2 at this time. n The control voltage value and the measured delay; if there is no optical signal output from the Out0 port, it proves that the optical signal is output from the Out1 port. At this time, apply the other control voltage value of its two control voltages to the optical switch S1 to make the optical signal output from the Out0 port, and record the optical switch S1~S n The control voltage value and the measured delay; (4.3) The delay amount of each transmission path is a pre-designed fixed value. Based on the delay amount obtained by the test, the transmission path of the optical signal in the optical switch switching delay chip is determined, thereby determining the "straight-through" and "cross-through" states corresponding to the two control voltages of the optical switch.

7. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, The optical transmission medium of the optical switch switching delay chip is not limited to silicon.

8. The non-destructive calibration method for the optical switch control voltage in an optical switch switching delay chip according to claim 1, characterized in that, The optical switch is not limited to the MZI type 4-port structure.

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