Thermal-optical modulator bias voltage control method, device, equipment and storage medium

Abstract

The application provides a thermal-optic modulator bias voltage control method, device, equipment and storage medium. The method comprises the following steps: setting a first bias voltage of a target heater as a first target voltage, setting a second bias voltage as a second target voltage, and obtaining a target output value of a thermal-optic modulator. In each adjustment period, a current output value of the thermal-optic modulator is obtained. If the absolute value of the difference between the current output value and the target output value is greater than an error allowed value, the first bias voltage and the second bias voltage are adjusted according to a preset rule, otherwise the first bias voltage and the second bias voltage remain unchanged. The preset rule comprises: one of the first bias voltage and the second bias voltage is increased, and the other is decreased, and the absolute value of the square difference of the first bias voltage before and after adjustment and the absolute value of the square difference of the second bias voltage before and after adjustment are equal to a first preset constant. Through the application, the linear control of the thermal-optic modulator can be guaranteed, and the fluctuation of the overall temperature of the thermal-optic modulator can be reduced as much as possible.

Description

Technical Field

[0001] The present application relates to the technical field of optical communication equipment, and in particular to a method, apparatus, device and storage medium for controlling bias voltage of a thermo-optical modulator. Background Art

[0002] The IQ (In-Phase Quadrature) modulator is a core optical component in coherent optical communication systems. Controlling the bias voltage of an IQ modulator directly determines the quality of the transmitted signal and is a crucial factor influencing system performance. In traditional lithium niobate (LNbO) modulators, the refractive index of the waveguide changes proportionally to the bias voltage. This linearity is achieved by maintaining a constant sum of the two bias voltages input to the modulator's sub-arms.

[0003] Due to the free-carrier effect, key parameters such as size, half-wave voltage, bandwidth, and insertion loss of lithium niobate modulators are no longer suitable for applications in higher-speed systems. Compared to traditional lithium niobate modulators, thermo-optical modulators such as indium phosphide and silicon optical modulators offer smaller size, higher phase voltage efficiency, higher bandwidth, and higher integration, and are widely used in 400G, 800G, and higher-speed systems.

[0004] Thermo-optic modulators utilize the thermo-optic effect of materials. The refractive index of the waveguide changes proportionally to temperature, rather than bias voltage. Using traditional control methods, where the sum of the two bias voltages is constant, would not guarantee linear control of the thermo-optic modulator and would also cause significant fluctuations in the overall temperature of the modulator, increasing the complexity of the control algorithm. Summary of the Invention

[0005] The present application provides a method, apparatus, device and storage medium for controlling the bias voltage of a thermo-optical modulator, which can ensure linear control of the thermo-optical modulator and minimize fluctuations in the overall temperature of the thermo-optical modulator.

[0006] In a first aspect, an embodiment of the present application provides a method for controlling a bias voltage of a thermo-optical modulator, the method comprising:

[0007] Setting the first bias voltage of the target heater to a first target voltage and the second bias voltage to a second target voltage, and obtaining a target output value of the thermo-optical modulator, wherein the output value of the thermo-optical modulator is a photocurrent or an optical power, and the target heater is used to adjust the refractive index of the waveguide of one of the sub-arms of the thermo-optical modulator under the control of the differential input first bias voltage and the second bias voltage;

[0008] In each adjustment cycle, the current output value of the thermo-optical modulator is obtained. If the absolute value of the difference between the current output value and the target output value is greater than the allowable error value, the first bias voltage and the second bias voltage are adjusted according to a preset rule; otherwise, the first bias voltage and the second bias voltage are kept unchanged, wherein the preset rule includes: increasing one of the first bias voltage and the second bias voltage and decreasing the other, and the absolute value of the square difference of the first bias voltage before and after adjustment and the absolute value of the square difference of the second bias voltage before and after adjustment are both equal to a first preset constant.

[0009] Furthermore, in one embodiment, the step of adjusting the first bias voltage and the second bias voltage according to a preset rule includes:

[0010] If the current output value is less than the target output value, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing;

[0011] If the current output value is greater than the target output value, the first bias voltage is adjusted in the second direction, and the second bias voltage is adjusted in the first direction.

[0012] Furthermore, in one embodiment, the step of adjusting the first bias voltage and the second bias voltage according to a preset rule includes:

[0013] If the first bias voltage and the second bias voltage are not adjusted in the previous adjustment cycle, then in the current adjustment cycle, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing;

[0014] If the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction in the previous adjustment cycle, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction;

[0015] If, in a previous adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction, and the current output value after the adjustment is further away from the target output value than the current output value before the adjustment, then, in the current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction;

[0016] If, in a previous adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then, in a current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction;

[0017] If the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction in the previous adjustment cycle, and the current output value after adjustment is further away from the target output value than the current output value before adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction.

[0018] Furthermore, in one embodiment, before the step of setting the first bias voltage of the target heater to the first target voltage, setting the second bias voltage to the second target voltage, and obtaining the target output value of the thermo-optical modulator, the step further includes:

[0019] In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , obtain the output value of the thermo-optical modulator;

[0020] In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x>1, a is a second preset constant;

[0021] One of the first bias voltage and the second bias voltage of all sample settings and the sampled output value of the thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage. When the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point in the sine function; when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point in the sine function.

[0022] Furthermore, in one embodiment, in a certain sampling, the first bias voltage is equal to the second bias voltage, and the corresponding point of the sampling in the sine function is defined as a reference point;

[0023] When the sub-arm corresponding to the target heater is I-channel or Q-channel, the optimal operating point is the Null point closest to the reference point in the sine function. When the sub-arm corresponding to the target heater is P-channel, the optimal operating point is the Quad point closest to the reference point in the sine function.

[0024] Furthermore, in one embodiment, in the first sampling, the first bias voltage is equal to the second bias voltage.

[0025] Furthermore, in one embodiment, before the step of setting the first bias voltage of the target heater to the first target voltage, setting the second bias voltage to the second target voltage, and obtaining the target output value of the thermo-optical modulator, the step further includes:

[0026] In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , get the output value of the thermo-optical modulator, where V P(1) =V N(1) =b, b is a third preset constant, b>0;

[0027] In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x∈[2, M-1], a is the second preset constant, a>0, V P(M-1) 2 +a≥2b 2 , V N(M-1) 2 -a≤0;

[0028] In the Mth sampling, the first bias voltage of the target heater is set to V P(M) , the second bias voltage is set to V N(M) , get the output value of the thermo-optical modulator, where V N(M) =0;

[0029] One of the first bias voltage and the second bias voltage of all sampling settings and the output value of the sampled thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage, wherein the corresponding point of the first sampling in the sine function is defined as the reference point, when the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point closest to the reference point in the sine function, and when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point closest to the reference point in the sine function.

[0030] In a second aspect, an embodiment of the present application further provides a device for controlling a bias voltage of a thermo-optical modulator, the device comprising:

[0031] a target setting module, configured to set a first bias voltage of a target heater to a first target voltage and a second bias voltage to a second target voltage, and obtain a target output value of the thermo-optical modulator, wherein the output value of the thermo-optical modulator is a photocurrent or an optical power, and the target heater is configured to adjust the refractive index of a waveguide of one of the sub-arms of the thermo-optical modulator under the control of the differential input first bias voltage and the second bias voltage;

[0032] The target tracking module is used to obtain the current output value of the thermo-optical modulator in each adjustment cycle, and if the absolute value of the difference between the current output value and the target output value is greater than the error allowable value, adjust the first bias voltage and the second bias voltage according to a preset rule; otherwise, keep the first bias voltage and the second bias voltage unchanged, wherein the preset rule includes: increasing one of the first bias voltage and the second bias voltage and decreasing the other, and the absolute value of the square difference of the first bias voltage before and after adjustment and the absolute value of the square difference of the second bias voltage before and after adjustment are both equal to a first preset constant.

[0033] In a third aspect, an embodiment of the present application further provides a thermo-optical modulator bias voltage control device, which includes a processor, a memory, and a thermo-optical modulator bias voltage control program stored in the memory and executable by the processor, wherein when the thermo-optical modulator bias voltage control program is executed by the processor, the steps of the above-mentioned thermo-optical modulator bias voltage control method are implemented.

[0034] In a fourth aspect, an embodiment of the present application further provides a storage medium, on which a thermo-optical modulator bias voltage control program is stored, wherein when the thermo-optical modulator bias voltage control program is executed by a processor, the steps of the above-mentioned thermo-optical modulator bias voltage control method are implemented.

[0035] In the present application, the adjustment operation in the tracking control stage is constrained by preset rules, and the square difference between the first bias voltage and the second bias voltage changes linearly, so that the thermal power applied by the target heater to the waveguide of the sub-arm changes linearly, and thus the refractive index of the waveguide changes linearly, thereby ensuring the linear control of the thermo-optical modulator. The sum of the squares of the first bias voltage and the second bias voltage remains unchanged, so that the thermal power applied by the target heater to the entire thermo-optical modulator remains unchanged, thereby minimizing the fluctuation of the overall temperature of the thermo-optical modulator. Through the present application, the linear control of the thermo-optical modulator can be guaranteed in the tracking control stage, and the fluctuation of the overall temperature of the thermo-optical modulator can be minimized, which helps to improve the control accuracy of the thermo-optical modulator and reduce the complexity of the control algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is a flow chart of a method for controlling bias voltage of a thermo-optical modulator in one embodiment of the present application;

[0037] Figure 2 Schematic diagram of the structure of a bias voltage feedback control circuit of a thermo-optical modulator in one embodiment of the present application;

[0038] Figure 3 This is a schematic structural diagram of a thermo-optical modulator in one embodiment of the present application;

[0039] Figure 4 This is a schematic structural diagram of a target heater in one embodiment of the present application;

[0040] Figure 5 Schematic diagram of the functional modules of a bias voltage control device for a thermo-optical modulator in one embodiment of the present application;

[0041] Figure 6 This is a schematic diagram of the hardware structure of the thermo-optical modulator bias voltage control device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0044] In a first aspect, an embodiment of the present application provides a method for controlling a bias voltage of a thermo-optical modulator.

[0045] Figure 1 A flow chart of a method for controlling a bias voltage of a thermo-optical modulator in an embodiment of the present application is shown.

[0046] Reference Figure 1 In one embodiment, a method for controlling a bias voltage of a thermo-optical modulator includes the following steps:

[0047] S11. Set the first bias voltage of the target heater to the first target voltage and the second bias voltage to the second target voltage to obtain the target output value of the thermo-optical modulator, wherein the output value of the thermo-optical modulator is photocurrent or optical power, and the target heater is used to adjust the refractive index of the waveguide of one of the sub-arms of the thermo-optical modulator under the control of the differential input first bias voltage and the second bias voltage.

[0048] Figure 2 A schematic structural diagram of a bias voltage feedback control circuit for a thermo-optical modulator in an embodiment of the present application is shown.

[0049] Reference Figure 2 In the feedback control circuit of the bias voltage, the control platform calculates the digital signal of the bias voltage, which is converted into an analog signal of the bias voltage through a digital-to-analog converter and loaded onto the thermo-optical modulator. The thermo-optical modulator modulates the incident light signal under the control of the bias voltage to obtain an output light signal, which is converted into an analog signal of an output electrical signal through a photoelectric converter, and the analog signal of the output electrical signal is converted into a digital signal of an output electrical signal through an analog-to-digital converter, specifically a photocurrent or optical power, which is fed back to the control platform. The control platform adjusts the bias voltage based on the feedback photocurrent or optical power.

[0050] Figure 3 A schematic structural diagram of a thermo-optical modulator in an embodiment of the present application is shown.

[0051] Reference Figure 3 The thermo-optical modulator has six sub-arms, corresponding to the X polarization state and the Y polarization state respectively. Each polarization state is divided into I (In-phase), Q (Quadrature) and P (Phase) paths. Each sub-arm is controlled by a corresponding heater at the differential input bias voltage V P and V N The refractive index of the waveguide is adjusted under the control of . The bias voltage control of the six sub-arms is divided into six time slots, namely XI, XQ, XP, YI, YQ, and YP. In this embodiment, the bias voltage control of one sub-arm is described. The heater corresponding to this sub-arm is referred to as the target heater, and the bias voltages input to the target heater are referred to as the first bias voltage and the second bias voltage.

[0052] Figure 4A schematic structural diagram of a target heater in an embodiment of the present application is shown.

[0053] Reference Figure 4 A first input terminal and a second input terminal are provided on one side of the target heater, and the other side is grounded. A first heating resistor is provided between the first input terminal and the other side, and a second heating resistor is provided between the second input terminal and the other side. A first bias voltage is input to the first heating resistor through the first input terminal, and a second bias voltage is input to the second heating resistor through the second input terminal. The resistance values ​​of the first heating resistor and the second heating resistor are equal.

[0054] The resistance of the first heating resistor and the second heating resistor are represented as R, and the first bias voltage is represented as V P , the second bias voltage is expressed as V N , the thermal power of the target heater acting on the waveguide of the sub-arm is The thermal power of the target heater acting on the entire thermo-optical modulator is

[0055] After the light field propagates through the waveguide, a spatial phase shift occurs, and the phase shift amount is: n is the refractive index, λ is the wavelength of light. For thermo-optical effect materials, the thermo-optic coefficient k = dn / dT. When the refractive index changes, ΔT is the temperature change. Since the temperature change of the waveguide is basically proportional to the change of the thermal power acting on the waveguide, π, λ, and k are all constants. and Δ P 1 is directly proportional. P in 、P out are the input optical power and output optical power of the thermo-optical modulator, P in Keeping it unchanged, we can deduce P out ∝cos(ΔP1), so when P1 changes linearly, the linear control of the thermo-optical modulator can be guaranteed, and when P2 remains unchanged, the fluctuation of the overall temperature of the thermo-optical modulator can be minimized.

[0056] In this embodiment, the first target voltage and the second target voltage are used to make the thermo-optical modulator in the initial state operate at the optimal operating point to obtain the target output value of the thermo-optical modulator. The operating point of the thermo-optical modulator will drift with factors such as operating time, temperature changes, and aging. Therefore, during the operation of the thermo-optical modulator, it is necessary to track and control the bias voltage and adjust the bias voltage so that the current output value of the thermo-optical modulator is as close to the target output value as possible.

[0057] S12. In each adjustment cycle, obtain the current output value of the thermo-optical modulator. If the absolute value of the difference between the current output value and the target output value is greater than the allowable error value, adjust the first bias voltage and the second bias voltage according to a preset rule; otherwise, keep the first bias voltage and the second bias voltage unchanged, wherein the preset rule includes: increasing one of the first bias voltage and the second bias voltage and decreasing the other, and the absolute value of the square difference of the first bias voltage before and after the adjustment and the absolute value of the square difference of the second bias voltage before and after the adjustment are both equal to a first preset constant.

[0058] It can be understood that if the absolute value of the difference between the current output value and the target output value is less than or equal to the allowable error value, the thermo-optical modulator is considered to be operating at the optimal operating point and there is no need to adjust the first bias voltage and the second bias voltage. If the absolute value of the difference between the current output value and the target output value is greater than the allowable error value, the thermo-optical modulator is considered to deviate from the optimal operating point and the first bias voltage and the second bias voltage need to be adjusted.

[0059] In this embodiment, the adjustment of the first and second bias voltages is constrained by a preset rule. For the bias voltage that is increased, the square of the adjusted bias voltage increases by a first preset constant compared to the square of the bias voltage before adjustment. For the bias voltage that is decreased, the square of the adjusted bias voltage decreases by a first preset constant compared to the square of the bias voltage before adjustment. Therefore, during each adjustment process, the absolute value of the square difference between the adjusted first and second bias voltages differs by twice the first preset constant compared to the absolute value of the square difference between the first and second bias voltages before adjustment. The sum of the squares of the adjusted first and second bias voltages remains constant compared to the sum of the squares of the first and second bias voltages before adjustment, i.e., is equal to the sum of the squares of the first and second target voltages.

[0060] Therefore, in this embodiment, during the tracking control phase, the adjustment operation is constrained by preset rules, and the difference between the squares of the first bias voltage and the second bias voltage varies linearly, causing the thermal power applied by the target heater to the waveguide of the sub-arm to vary linearly, thereby causing the refractive index of the waveguide to vary linearly, thereby ensuring linear control of the thermo-optical modulator. The sum of the squares of the first bias voltage and the second bias voltage remains constant, thereby maintaining the thermal power applied by the target heater to the entire thermo-optical modulator, thereby minimizing fluctuations in the overall temperature of the thermo-optical modulator. This embodiment ensures linear control of the thermo-optical modulator during the tracking control phase and minimizes fluctuations in the overall temperature of the thermo-optical modulator, thereby improving the control accuracy of the thermo-optical modulator and reducing the complexity of the control algorithm.

[0061] It should be noted that in different adjustment cycles, the objects of the first bias voltage and the second bias voltage that are increased or decreased are not fixed and need to be determined in combination with other conditions.

[0062] Furthermore, in one embodiment, the step of adjusting the first bias voltage and the second bias voltage according to a preset rule includes:

[0063] If the current output value is less than the target output value, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing;

[0064] If the current output value is greater than the target output value, the first bias voltage is adjusted in the second direction, and the second bias voltage is adjusted in the first direction.

[0065] In this embodiment, assuming that the first bias voltage, the second bias voltage and the change trend of the output value within the adjustment range have a certain relationship, then the adjustment direction of the first bias voltage and the second bias voltage can be directly determined according to the magnitude relationship between the current output value and the target output value.

[0066] Specifically, if the output value within the adjustment range increases with the increase of the first bias voltage and decreases with the increase of the second bias voltage, when the current output value is less than the target output value, if you want to increase the current output value, you need to increase the first bias voltage and decrease the second bias voltage. Correspondingly, when the current output value is greater than the target output value, if you want to decrease the current output value, you need to decrease the first bias voltage and increase the second bias voltage. Therefore, the first direction is set to increase and the second direction is set to decrease.

[0067] If the output value within the adjustment range decreases with the increase of the first bias voltage and increases with the increase of the second bias voltage, when the current output value is less than the target output value, if you want to increase the current output value, you need to reduce the first bias voltage and increase the second bias voltage. Correspondingly, when the current output value is greater than the target output value, if you want to reduce the current output value, you need to increase the first bias voltage and reduce the second bias voltage. Therefore, the first direction is set to decrease and the second direction is set to increase.

[0068] Accordingly, if the changing trends of the first bias voltage, the second bias voltage and the output value within the adjustment range do not have a definite relationship, the adjustment direction of the first bias voltage and the second bias voltage cannot be determined only based on the magnitude relationship between the current output value and the target output value.

[0069] Furthermore, in one embodiment, the step of adjusting the first bias voltage and the second bias voltage according to a preset rule includes:

[0070] If the first bias voltage and the second bias voltage are not adjusted in the previous adjustment cycle, then in the current adjustment cycle, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing;

[0071] If the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction in the previous adjustment cycle, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction;

[0072] If, in a previous adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction, and the current output value after the adjustment is further away from the target output value than the current output value before the adjustment, then, in the current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction;

[0073] If, in a previous adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then, in a current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction;

[0074] If the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction in the previous adjustment cycle, and the current output value after adjustment is further away from the target output value than the current output value before adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction.

[0075] In this embodiment, after the operating point of the thermo-optical modulator deviates from the optimal operating point, a trial adjustment is first performed according to a default method. Subsequently, the next adjustment direction is determined based on the previous adjustment direction and adjustment results. If the current output value after adjustment is closer to the target output value, it indicates that the previous adjustment direction was correct and the previous adjustment direction is continued. If the current output value after adjustment is further away from the target output value, it indicates that the previous adjustment direction was incorrect and the opposite adjustment direction is used. This embodiment allows the correct adjustment direction to be found regardless of whether the changing trends of the first bias voltage, the second bias voltage, and the output value within the adjustment range have a definite relationship.

[0076] Furthermore, in one embodiment, before the step of setting the first bias voltage of the target heater to the first target voltage, setting the second bias voltage to the second target voltage, and obtaining the target output value of the thermo-optical modulator, the step further includes:

[0077] In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , obtain the output value of the thermo-optical modulator;

[0078] In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x>1, a is a second preset constant;

[0079] One of the first bias voltage and the second bias voltage of all sample settings and the sampled output value of the thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage. When the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point in the sine function; when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point in the sine function.

[0080] In this embodiment, during the initialization phase, multiple sampling operations are performed to obtain the first bias voltage, second bias voltage, and output value at different operating points. Since the first bias voltage and the second bias voltage correspond one-to-one, either can be fitted with the output value to form a sine function. This sine function is the transmission curve of the corresponding sub-arm of the thermo-optical modulator. Based on the type of sub-arm, the corresponding optimal operating point is selected from this function to determine the first target voltage and the second target voltage. The null point is also called the minimum point or valley point, and the quadrature point is also called the quadrature point.

[0081] In the second and subsequent samplings, relative to the previous sampling, one of the first bias voltage and the second bias voltage is increased and the other is decreased. The square difference between the first bias voltage of the current sampling and the previous sampling is equal to the second preset constant, and the square difference between the second bias voltage of the current sampling and the previous sampling is equal to the inverse of the second preset constant. For example, when the second preset constant is greater than zero, the first bias voltage is increased and the second bias voltage is decreased each time. When the second preset constant is less than zero, the first bias voltage is decreased and the second bias voltage is increased each time.

[0082] Combined with the analysis in the previous article, it can be seen that in the initialization stage, in the adjustment operation of two adjacent samplings, the absolute value of the square difference between the first bias voltage and the second bias voltage after adjustment is twice the second preset constant compared with the absolute value of the square difference between the first bias voltage and the second bias voltage before adjustment. The sum of the squares of the first bias voltage and the second bias voltage after adjustment remains unchanged compared with the sum of the squares of the first bias voltage and the second bias voltage before adjustment, that is, equal to the sum of the squares of the first bias voltage and the second bias voltage in the first sampling.

[0083] Therefore, through this embodiment, the linear control of the thermo-optical modulator can be guaranteed during the initialization stage, and the fluctuation of the overall temperature of the thermo-optical modulator can be reduced as much as possible, thereby reducing the difficulty and time consumption of the initialization operation.

[0084] Furthermore, in one embodiment, in a certain sampling, the first bias voltage is equal to the second bias voltage, and the corresponding point of the sampling in the sine function is defined as a reference point;

[0085] When the sub-arm corresponding to the target heater is I-channel or Q-channel, the optimal operating point is the Null point closest to the reference point in the sine function. When the sub-arm corresponding to the target heater is P-channel, the optimal operating point is the Quad point closest to the reference point in the sine function.

[0086] Specifically, a sine function may cover multiple cycles, meaning there are multiple Null points and Quad points. Regardless of the device's available voltage range, selecting any of these points will achieve the same effect. However, if the device's available voltage range is considered, when the first bias voltage equals the second bias voltage, the adjustable range for both increases and decreases is the same. Using this as a reference point, selecting the Null point or Quad point closest to the reference point as the optimal operating point maximizes the balance between the adjustable range for increases and decreases, helping to reduce device cost.

[0087] Furthermore, in one embodiment, in the first sampling, the first bias voltage is equal to the second bias voltage. In this way, the reference point can be determined through the first sampling, thereby simplifying the adjustment scheme.

[0088] Furthermore, in one embodiment, before the step of setting the first bias voltage of the target heater to the first target voltage, setting the second bias voltage to the second target voltage, and obtaining the target output value of the thermo-optical modulator, the step further includes:

[0089] In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , get the output value of the thermo-optical modulator, where V P(1) =V N(1)=b, b is a third preset constant, b>0;

[0090] In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x∈[2, M-1], a is the second preset constant, a>0, V P(M-1) 2 +a≥2b 2 , V N(M-1) 2 -a≤0;

[0091] In the Mth sampling, the first bias voltage of the target heater is set to V P(M) , the second bias voltage is set to V N(M) , get the output value of the thermo-optical modulator, where V N(M) =0;

[0092] One of the first bias voltage and the second bias voltage of all sampling settings and the output value of the sampled thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage, wherein the corresponding point of the first sampling in the sine function is defined as the reference point, when the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point closest to the reference point in the sine function, and when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point closest to the reference point in the sine function.

[0093] In this embodiment, the first bias voltage and the second bias voltage in the first sampling are both set to b, and in each sampling, the sum of the squares of the first bias voltage and the second bias voltage is kept equal to 2b 2 , so as to minimize the fluctuation of the overall temperature of the thermo-optical modulator. Before the Mth sampling, the square of the first bias voltage is controlled by b 2 Increase the equal step size by 2b 2 , the square of the second bias voltage is controlled by b 2 The step size is reduced to 0, thereby ensuring the linear control of the thermo-optical modulator. Through this embodiment, a sine function covering multiple periods and including a reference point can be fitted.

[0094] Optionally, 2b2 It is an integer multiple of the resistance R of the first heating resistor and the second heating resistor.

[0095] In a second aspect, an embodiment of the present application further provides a bias voltage control device for a thermo-optical modulator.

[0096] Figure 5 A functional module schematic diagram of a bias voltage control device for a thermo-optical modulator in an embodiment of the present application is shown.

[0097] Reference Figure 5 In one embodiment, the bias voltage control device for the thermo-optical modulator includes:

[0098] a target setting module 10, configured to set a first bias voltage of a target heater to a first target voltage and a second bias voltage to a second target voltage, and obtain a target output value of the thermo-optical modulator, wherein the output value of the thermo-optical modulator is a photocurrent or an optical power, and the target heater is configured to adjust the refractive index of a waveguide of one of the sub-arms of the thermo-optical modulator under the control of the differential input first bias voltage and the second bias voltage;

[0099] The target tracking module 20 is used to obtain the current output value of the thermo-optical modulator in each adjustment cycle. If the absolute value of the difference between the current output value and the target output value is greater than the error allowable value, the first bias voltage and the second bias voltage are adjusted according to a preset rule; otherwise, the first bias voltage and the second bias voltage are kept unchanged, wherein the preset rule includes: increasing one of the first bias voltage and the second bias voltage and decreasing the other, and the absolute value of the square difference of the first bias voltage before and after the adjustment and the absolute value of the square difference of the second bias voltage before and after the adjustment are both equal to a first preset constant.

[0100] Furthermore, in one embodiment, the target tracking module 20 is configured to:

[0101] If the current output value is less than the target output value, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing;

[0102] If the current output value is greater than the target output value, the first bias voltage is adjusted in the second direction, and the second bias voltage is adjusted in the first direction.

[0103] Furthermore, in one embodiment, the target tracking module 20 is configured to:

[0104] If the first bias voltage and the second bias voltage are not adjusted in the previous adjustment cycle, then in the current adjustment cycle, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing;

[0105] If the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction in the previous adjustment cycle, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction;

[0106] If, in a previous adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction, and the current output value after the adjustment is further away from the target output value than the current output value before the adjustment, then, in the current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction;

[0107] If, in a previous adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then, in a current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction;

[0108] If the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction in the previous adjustment cycle, and the current output value after adjustment is further away from the target output value than the current output value before adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction.

[0109] Furthermore, in one embodiment, the thermo-optical modulator bias voltage control device further includes an initialization module 30, configured to:

[0110] In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , obtain the output value of the thermo-optical modulator;

[0111] In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1)2 =-a, x>1, a is a second preset constant;

[0112] One of the first bias voltage and the second bias voltage of all sample settings and the sampled output value of the thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage. When the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point in the sine function; when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point in the sine function.

[0113] Furthermore, in one embodiment, in a certain sampling, the first bias voltage is equal to the second bias voltage, and the corresponding point of the sampling in the sine function is defined as a reference point;

[0114] When the sub-arm corresponding to the target heater is I-channel or Q-channel, the optimal operating point is the Null point closest to the reference point in the sine function. When the sub-arm corresponding to the target heater is P-channel, the optimal operating point is the Quad point closest to the reference point in the sine function.

[0115] Furthermore, in one embodiment, in the first sampling, the first bias voltage is equal to the second bias voltage.

[0116] Furthermore, in one embodiment, the thermo-optical modulator bias voltage control device further includes an initialization module 30, configured to:

[0117] In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , get the output value of the thermo-optical modulator, where V P(1) =V N(1) =b, b is a third preset constant, b>0;

[0118] In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x∈[2, M-1], a is the second preset constant, a>0, V P(M-1) 2 +a≥2b 2 , V N(M-1)2 -a≤0;

[0119] In the Mth sampling, the first bias voltage of the target heater is set to V P(M) , the second bias voltage is set to V N(M) , get the output value of the thermo-optical modulator, where V N(M) =0;

[0120] One of the first bias voltage and the second bias voltage of all sampling settings and the output value of the sampled thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage, wherein the corresponding point of the first sampling in the sine function is defined as the reference point, when the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point closest to the reference point in the sine function, and when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point closest to the reference point in the sine function.

[0121] Among them, the functional implementation of each module in the above-mentioned thermo-optical modulator bias voltage control device corresponds to the various steps in the above-mentioned thermo-optical modulator bias voltage control method embodiment, and their functions and implementation processes are not repeated here one by one.

[0122] In a third aspect, an embodiment of the present application provides a bias voltage control device for a thermo-optical modulator. The bias voltage control device for a thermo-optical modulator may be a device with data processing capabilities, such as a personal computer (PC), a laptop computer, or a server.

[0123] Figure 6 A schematic diagram of the hardware structure of a thermo-optical modulator bias voltage control device involved in an embodiment of the present application is shown.

[0124] Reference Figure 6 In an embodiment of the present application, the thermo-optical modulator bias voltage control device may include a processor, a memory, a communication interface, and a communication bus.

[0125] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0126] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the thermo-optical modulator bias voltage control device, as well as interfaces used to interconnect the thermo-optical modulator bias voltage control device with other devices (e.g., other computing devices or user devices). Physical interfaces can include Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc. User devices can include displays, keyboards, etc.

[0127] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0128] The processor may be a general-purpose processor that can call a thermo-optical modulator bias voltage control program stored in a memory and execute the thermo-optical modulator bias voltage control method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the thermo-optical modulator bias voltage control program is called may refer to the various embodiments of the thermo-optical modulator bias voltage control method of the present application and will not be further described here.

[0129] Those skilled in the art will understand that Figure 6 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0130] In a fourth aspect, an embodiment of the present application also provides a storage medium.

[0131] The storage medium of the present application stores a thermo-optical modulator bias voltage control program, wherein when the thermo-optical modulator bias voltage control program is executed by a processor, the steps of the above-mentioned thermo-optical modulator bias voltage control method are implemented.

[0132] The method implemented when the thermo-optical modulator bias voltage control program is executed can refer to the various embodiments of the thermo-optical modulator bias voltage control method of the present application, and will not be described in detail here.

[0133] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0134] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0135] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0136] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0137] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0138] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0139] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for controlling bias voltage of a thermo-optical modulator, characterized in that: The thermo-optical modulator bias voltage control method includes: Setting the first bias voltage of the target heater to a first target voltage and the second bias voltage to a second target voltage, and obtaining a target output value of the thermo-optical modulator, wherein the output value of the thermo-optical modulator is a photocurrent or an optical power, and the target heater is used to adjust the refractive index of the waveguide of one of the sub-arms of the thermo-optical modulator under the control of the differential input first bias voltage and the second bias voltage; In each adjustment cycle, the current output value of the thermo-optical modulator is obtained. If the absolute value of the difference between the current output value and the target output value is greater than the allowable error value, the first bias voltage and the second bias voltage are adjusted according to a preset rule; otherwise, the first bias voltage and the second bias voltage are kept unchanged, wherein the preset rule includes: increasing one of the first bias voltage and the second bias voltage and decreasing the other, and the absolute value of the square difference of the first bias voltage before and after adjustment and the absolute value of the square difference of the second bias voltage before and after adjustment are both equal to a first preset constant.

2. The method for controlling the bias voltage of a thermo-optical modulator according to claim 1, wherein: The step of adjusting the first bias voltage and the second bias voltage according to a preset rule includes: If the current output value is less than the target output value, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing; If the current output value is greater than the target output value, the first bias voltage is adjusted in the second direction, and the second bias voltage is adjusted in the first direction.

3. The method for controlling the bias voltage of a thermo-optical modulator according to claim 1, wherein: The step of adjusting the first bias voltage and the second bias voltage according to a preset rule includes: If the first bias voltage and the second bias voltage are not adjusted in the previous adjustment cycle, then in the current adjustment cycle, the first bias voltage is adjusted in a first direction and the second bias voltage is adjusted in a second direction, wherein the first direction is increasing and the second direction is decreasing, or the first direction is decreasing and the second direction is increasing; If the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction in the previous adjustment cycle, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction; If, in a previous adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction, and the current output value after the adjustment is further away from the target output value than the current output value before the adjustment, then, in the current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction; If, in a previous adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction, and the current output value after the adjustment is closer to the target output value than the current output value before the adjustment, then, in a current adjustment cycle, the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction; If the first bias voltage is adjusted in the second direction and the second bias voltage is adjusted in the first direction in the previous adjustment cycle, and the current output value after adjustment is further away from the target output value than the current output value before adjustment, then in the current adjustment cycle, the first bias voltage is adjusted in the first direction and the second bias voltage is adjusted in the second direction.

4. The method for controlling the bias voltage of a thermo-optical modulator according to claim 1, wherein: Before the step of setting the first bias voltage of the target heater to the first target voltage and the second bias voltage to the second target voltage to obtain the target output value of the thermo-optical modulator, the method further includes: In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , obtain the output value of the thermo-optical modulator; In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x>1, a is a second preset constant; One of the first bias voltage and the second bias voltage of all sample settings and the sampled output value of the thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage. When the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point in the sine function; when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point in the sine function.

5. The method for controlling the bias voltage of a thermo-optical modulator according to claim 4, wherein: In a certain sampling, the first bias voltage is equal to the second bias voltage, and the corresponding point of the sampling in the sine function is defined as the reference point; When the sub-arm corresponding to the target heater is I-channel or Q-channel, the optimal operating point is the Null point closest to the reference point in the sine function. When the sub-arm corresponding to the target heater is P-channel, the optimal operating point is the Quad point closest to the reference point in the sine function.

6. The method for controlling the bias voltage of a thermo-optical modulator according to claim 5, wherein: In the first sampling, the first bias voltage is equal to the second bias voltage.

7. The method for controlling the bias voltage of a thermo-optical modulator according to claim 1, wherein: Before the step of setting the first bias voltage of the target heater to the first target voltage and the second bias voltage to the second target voltage to obtain the target output value of the thermo-optical modulator, the method further includes: In the first sampling, the first bias voltage of the target heater is set to V P(1) , the second bias voltage is set to V N(1) , get the output value of the thermo-optical modulator, where V P(1) =V N(1) =b, b is a third preset constant, b>0; In the xth sampling, the first bias voltage of the target heater is set to V P(x) , the second bias voltage is set to V N(x) , get the output value of the thermo-optical modulator, where V P(x) 2 -V P(x-1) 2 =a,V N(x) 2 -V N(x-1) 2 =-a, x∈[2,M-1], a is the second preset constant, a>0, V P(M-1) 2 +a≥2b 2 , V N(M-1) 2 -a≤0; In the Mth sampling, the first bias voltage of the target heater is set to V P(M) , the second bias voltage is set to V N(M) , get the output value of the thermo-optical modulator, where V N(M) =0; One of the first bias voltage and the second bias voltage of all sampling settings and the output value of the sampled thermo-optical modulator are fitted into a sine function, the optimal operating point is selected from the sine function, the first bias voltage corresponding to the optimal operating point is determined as the first target voltage, and the second bias voltage is determined as the second target voltage, wherein the corresponding point of the first sampling in the sine function is defined as the reference point, when the sub-arm corresponding to the target heater is the I-path or the Q-path, the optimal operating point is the Null point closest to the reference point in the sine function, and when the sub-arm corresponding to the target heater is the P-path, the optimal operating point is the Quad point closest to the reference point in the sine function.

8. A bias voltage control device for a thermo-optical modulator, characterized in that: The thermal optical modulator bias voltage control device comprises: a target setting module, configured to set a first bias voltage of a target heater to a first target voltage and a second bias voltage to a second target voltage, and obtain a target output value of the thermo-optical modulator, wherein the output value of the thermo-optical modulator is a photocurrent or an optical power, and the target heater is configured to adjust the refractive index of a waveguide of one of the sub-arms of the thermo-optical modulator under the control of the differential input first bias voltage and the second bias voltage; The target tracking module is used to obtain the current output value of the thermo-optical modulator in each adjustment cycle, and if the absolute value of the difference between the current output value and the target output value is greater than the error allowable value, adjust the first bias voltage and the second bias voltage according to a preset rule; otherwise, keep the first bias voltage and the second bias voltage unchanged, wherein the preset rule includes: increasing one of the first bias voltage and the second bias voltage and decreasing the other, and the absolute value of the square difference of the first bias voltage before and after adjustment and the absolute value of the square difference of the second bias voltage before and after adjustment are both equal to a first preset constant.

9. A thermo-optical modulator bias voltage control device, characterized in that: The thermo-optical modulator bias voltage control device includes a processor, a memory, and a thermo-optical modulator bias voltage control program stored in the memory and executable by the processor, wherein when the thermo-optical modulator bias voltage control program is executed by the processor, the steps of the thermo-optical modulator bias voltage control method as described in any one of claims 1 to 7 are implemented.

10. A storage medium, characterized in that: The storage medium stores a thermo-optical modulator bias voltage control program, wherein when the thermo-optical modulator bias voltage control program is executed by the processor, the steps of the thermo-optical modulator bias voltage control method according to any one of claims 1 to 7 are implemented.

Images