WO2009010007A1

WO2009010007A1 - A method, an apparatus and an optical modulator for phase adjustment

Info

Publication number: WO2009010007A1
Application number: PCT/CN2008/071642
Authority: WO
Inventors: Xiaoyan Fan
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-07-16
Filing date: 2008-07-15
Publication date: 2009-01-22
Also published as: CN101350674B; CN101350674A

Abstract

A method for phase adjustment comprises: obtaining a response signal including a low frequency disturbing signal, and obtaining a response signal with the frequency of the low frequency disturbing signal according to the said response signal; dividing a standard clock period with a predetermined length into two equal slots, and with a sampling clock sampling the said response signal with the frequency of the low frequency disturbing signal in the said slots; in the said two divided slots, obtaining sampling values of the said response signal; obtaining a characteristic value by using all the sampling values in each slot, and obtaining the characteristic difference value between two characteristic values; obtaining an adjusting difference value between the characteristic difference value and a predetermined threshold, and shifting the phase of the said low frequency disturbing signal with a corresponding angle according to the said adjusting difference value, in order to keep the phase difference between the low frequency disturbing signal and the response signal constant. An apparatus and an optical modulator for phase adjustment are also disclosed in this invention.

Description

Method, device and light modulator for phase adjustment

This application claims priority to Chinese Patent Application No. 200710135834.3, entitled "A Phase Adjustment Method, Apparatus, and Light Modulator", filed on July 16, 2007, the entire contents of which are incorporated by reference. Combined in this application.

5 Technical fields

The present invention relates to the field of communications technologies, and more particularly to a method, apparatus, and optical modulator for phase adjustment.

Background technique

With the continuous deepening of research in optical and electronic communication, optical communication has developed rapidly. In the optical transmission system

0 The distance from the unpowered relay in the system has reached hundreds of kilometers. When the fiber is transmitted, the external modulator is used to operate the laser in the continuous wave mode, which is simple and thorough to overcome the influence of the frequency ripple. In addition, it offers higher speeds, higher extinction ratios and greater power. Therefore, the external modulation technology is ideal for ultra-high speed, long-distance optical transmission.

Most of the current optical modulators are Mach-Zehnder modulators, among which mainly lithium niobate

5 (LiNbio3) modulator. The working principle of the lithium niobate modulator is described below.

The working principle of a lithium niobate modulator uses a characteristic that the refractive index of a particular material changes with the applied electric field to achieve a modulation function. The applied electric field causes a change in the refractive index of the material. The change in the refractive index causes a phase change of the modulated optical signal. The phase change of the optical signal is combined with a specific lithium gallium silicate (MZ) interferometer to cause an interference effect on the output signal. Thereby realizing the modulation of the light intensity,

!0 is the modulation of optical power.

The characteristic curve of the lithium niobate modulator operation is shown in Figure 1. The V coordinate represents the applied DC bias (Bias) voltage of the modulator. Different applied DC bias voltages correspond to different output optical powers. The Bias voltage operates at various voltage points to achieve maximum output power (MAX), minimum (MIN), two Quad points (ie, Quad-, Quad+), and other optical power points. During the working process of the modulator

In !5, when the light source is modulated by a high-speed non-return-to-zero (NRZ) code electrical signal, the modulator operates at two Quad points, with the lowest bit error rate for digital signal systems and minimal distortion for analog systems. Therefore, the voltage value of the applied DC bias voltage should be stabilized at Vpi/2 as much as possible to ensure that the optical power is stable at the Quad point, and the output optical modulation signal is optimal. However, in practice, the Bias voltage at the Quad point of the lithium niobate modulator will drift due to temperature (ie, the Quad point DC voltage changes with temperature;), That is, the input voltage Vin does not guarantee that the optical power is always stable at the Quad point. Therefore, it is necessary to continuously compensate for the drift of the DC Bias voltage, so that the output value of the optical power is locked at the Quad point. The prior art mainly uses the following two methods for bias control of the Bias voltage.

The first way is to use amplitude modulation bias control. The principle of amplitude modulation bias control is to use high frequency data signals.

No. 5 (RF) performs amplitude modulation, and Bias voltage control is realized by calculating the feedback value of the feedback signal of the modulator. The specific implementation process can be seen in Figure 2. The low frequency disturbance signal (periodic sinusoidal signal) is loaded to achieve amplitude modulation of the RF at the amplitude modulation end of the amplitude driver. The modulated signal, that is, the PD response signal, is extracted by the backlight detection photodiode (PD). The PD response signal is amplified, and frequency-selective filtering is performed on the frequency range of the low-frequency disturbance signal to obtain a PD response signal existing at a low-frequency disturbance frequency.

0 When the low frequency disturbance signal is forward disturbance or negative disturbance, the maximum and minimum values of the forward disturbance and the negative disturbance amplitude can be calculated by the bias control module synchronous demodulation, and the amplitude difference (Vpp) can be obtained. When Vpp is small and close to zero, it means that the modulator's Bias voltage works on ±Vpi/2, that is, the optical power works at the ±Quad point; when Vpp is large, it indicates that the modulator's Bias voltage works off ±Vpi/ 2, that is, the optical power has deviated from the Quarter point. With the size of Vpp, you will get the required Bias voltage.

5 Compensation value to compensate for Bias voltage.

The second way to add a low frequency disturbance signal is different from the first method, not by the amplitude modulation pin of the driver, but by the Bias end of the modulator. The offset of the Bias voltage is determined by calculating the Vpp of the PD response signal at the disturbance frequency of the low frequency disturbance signal and the Vpp of the output signal at the second harmonic frequency of the low frequency, thereby obtaining a compensation value for the Bias voltage.

In the process of implementing the present invention, the inventors have found through research that: the first mode and the second mode in the prior art described above only implement the PD response signal and the low frequency disturbance in the process of calculating the Bias voltage compensation value. When the phase difference of the signals is synchronized, Vpp can be accurately calculated to compensate for the Bias voltage. In order to make the PD response signal obtained from the modulator get the amplitude signal satisfying the calculation Vpp when the signal-to-noise ratio is very low, both methods use multi-stage filtering and multi-stage amplification circuits, due to

The 5th-stage filtering and multi-stage amplifying circuits have different phase changes at different temperatures, which causes the synchronization between the PD response signal and the low-frequency disturbance signal, and the phase difference occurs, which causes the deviation of the Vpp to be calculated and the Bias voltage to be lowered. Control accuracy; If part of the amplifier circuit and filter circuit are removed to reduce the phase difference, the PD signal will be degraded. Therefore, the problem of the phase difference between the PD response signal and the low frequency disturbance signal always plagues the control accuracy of the Bias voltage. Summary of the invention

Embodiments of the present invention provide a phase adjustment method, apparatus, and optical modulator capable of operating a bias voltage and power of a light modulator at a stable operating point, thereby outputting a stable optical modulation signal.

Embodiments of the present invention provide a method for phase adjustment, including:

5 obtaining a response signal including a low frequency disturbance signal, and obtaining a response signal having a frequency of the low frequency disturbance signal according to the response signal;

Dividing a predetermined length of the standard clock period into two equal time slots, wherein the response signal of the low frequency disturbance signal frequency is sampled by the sample clock in the time slot; wherein the response signal and the standard When the clock is synchronized, the waveforms of the response signals in the two time slots are symmetrical;

0 acquiring, in the divided two time slots, a sample value of the response signal;

A characterization value is obtained by using all the sample values in each time slot, and a characterization difference between the two characterization values is obtained;

Obtaining an adjustment difference between the characteristic difference value and a predetermined threshold value, and shifting the phase of the low frequency disturbance signal by a corresponding angle according to the adjustment difference value.

5 Embodiments of the present invention provide a phase adjustment apparatus, including:

a signal extracting unit, configured to obtain a response signal including a low frequency disturbance signal, and obtain a response signal having a frequency of the low frequency disturbance signal according to the response signal;

a standard clock unit for dividing a standard clock period of a predetermined length into two equal time slots and providing a standard clock signal; wherein, when the response signal is synchronized with the standard clock, the two time slots are within the The response signal waveform is symmetrical;

a sampling unit, configured to: in the time slot, the response signal of the low frequency disturbance signal frequency is sampled by the sampling clock; and obtaining the sample value of the response signal in the divided two time slots An operation unit, configured to obtain a characterization value by using all the sample values in each time slot, obtain a characterization difference between the two characterization values, and obtain an adjustment difference between the characterization difference value and a predetermined threshold value;

!5 an adjustment unit for moving the phase of the low frequency disturbance signal by a corresponding angle according to the adjustment difference.

Embodiments of the present invention provide a light modulator, including:

An input device for inputting a low frequency disturbance signal and an RF signal into the light modulator; a photoelectric conversion device for obtaining a modulated optical response signal having a low frequency disturbance signal, and The optical response signal is converted into a response signal;

Phase adjustment device, including:

a signal extracting unit, configured to obtain, from the photoelectric conversion device, a response signal including a low frequency disturbance signal, and obtain a response signal having a frequency of the low frequency disturbance signal according to the response signal;

a standard clock unit for dividing a standard clock period of a predetermined length into two equal time slots and providing a standard clock signal; wherein, when the response signal is synchronized with the standard clock, the two time slots are The response signal waveform is symmetrical;

a sampling unit, configured to: in the time slot, the response signal of the low frequency disturbance signal frequency is sampled by the sampling clock; and obtaining the sample value of the response signal in the divided two time slots 0 is an operation unit, configured to obtain a characterization value by using all the sample values in each time slot, obtain a characterization difference between the two characterization values, and obtain an adjustment difference between the characterization difference value and a predetermined threshold value; ;

An adjusting unit, configured to move a phase of the low frequency disturbance signal by a corresponding angle according to the adjustment difference;

And a bias voltage control device configured to perform a synchronous 5 demodulation calculation by using the low frequency disturbance signal and the response signal, and use the calculation result to increase or decrease the bias voltage.

The method and apparatus in the embodiments of the present invention can adjust the phase difference between the low frequency disturbance signal and the response signal, keep the phase difference between the low frequency disturbance signal and the response signal constant, and the phase difference is not affected by the temperature and the device, and is reduced. The cost of hardware design. The optical modulator in the embodiment of the present invention can perform synchronous demodulation calculation on the low frequency disturbance signal and the response signal, and use the calculation result to increase or decrease the bias of the !0 voltage, thereby improving the reliability of the lock bias voltage. The bias voltage and power of the optical modulator are operated at a stable operating point to output a stable optical modulation signal.

DRAWINGS

1 is a schematic diagram showing the characteristic curve of the operation of the lithium niobate modulator in the prior art;

2 is a schematic structural view of a lithium niobate modulator in the prior art;

Figure 5 is a structural diagram of a modulator according to Embodiment 1 of the present invention;

4 is a flow chart of Embodiment 1 of the present invention;

5 is a schematic diagram of a waveform when a standard signal and a response signal are synchronized in the first embodiment of the present invention; FIG. 6 is a schematic diagram showing a waveform of a response signal waveform deviating to the left in the first embodiment of the present invention; FIG. 7 is a first embodiment of the present invention; A schematic diagram of the response signal waveform deviating to the right from the standard signal waveform; Figure 8 is a structural diagram of a device in Embodiment 2 of the present invention;

Figure 9 is a structural diagram of a light modulator in Embodiment 3 of the present invention.

detailed description

A specific implementation scheme for adjusting the phase difference between the response signal and the low frequency 4 special motion signal will be described in detail below by way of an embodiment of the present invention.

First, a first embodiment of the present invention will be described in detail with reference to Figs. 3 and 4, see Fig. 3, in which the modulator uses an MZ type modulator, specifically a lithium niobate modulator. In the modulator, an electrical signal is obtained by photoelectric conversion after the PD end, and after filtering and amplification, AD is sampled, the digital processing chip judges by using the sample value, and the low frequency disturbance signal is adjusted by the result of the judgment. The specific actual process is shown in Figure 4, including the following steps:

Step 401: Obtain a response signal including a low frequency disturbance signal, and obtain a response signal having a frequency of the low frequency disturbance signal according to the response signal;

The optical response signal is obtained through the PD end of the modulator, and the optical response signal is photoelectrically converted to obtain a response signal, and the obtained response signal is filtered, and the filtering includes frequency selection, band pass, and filtering out the response signal having the frequency of the low frequency interference signal.

After the PD response signal is obtained, the following AD sample process will be performed. In this case, the frequency of the standard clock and the sample clock can be varied. In this embodiment, the standard clock is 1K, and the sample clock is 20Κ, that is, 20 times in the period of one standard clock signal.

Step 402: Divide a standard clock period of a predetermined length into two equal time slots, and sample the response signal in the time slot !0;

The predetermined length used may be one-half, or three-quarters of a standard clock cycle, or one standard clock cycle, or a plurality of standard clock cycles, and the like. When the response signal is sampled within a predetermined clock period of a predetermined length, it is necessary to divide the standard clock period of a predetermined length into two equal time slots, and the divided two time slots are not continuous. However, when the two time slots are synchronized, the response signal waveforms in the two time slots are symmetric when the response signal is synchronized with the standard time of 5 minutes, which may be mirror symmetry or origin symmetry.

For convenience of description, in this embodiment, the standard clock cycle length used is one-half of the standard clock cycle length, and the length is divided into two consecutive and equal time slots. For the waveform diagram of the response signal in the time slot divided by the standard clock cycle, see FIG. 5, FIG. 5 is a schematic diagram of the waveform when the standard clock and the response signal are synchronized, and the square waveform in FIG. 5 is a standard clock signal waveform. Party The wave is the signal time slot of the standard clock cycle, and the curve waveform is the waveform of the response signal. In the case of the sample, the forward direction of the response signal (i.e., the upper half axis in Fig. 5) and the negative direction (i.e., the lower half axis in Fig. 5) are sampled in the time slot of the square wave. In a time slot of a square wave, the sample values are obtained 10 times, and the sample values in the two time slots are separately counted.

5 Step 403: Record the obtained sample values in an array;

Step 404: Determine whether the number of times of each sample is less than the maximum number of samples;

In this embodiment, after each sample is finished, it is determined whether the number of times of the current sample is less than the maximum number of samples, that is, whether it is not equal to 10, and if not, proceeding to step 402 until the end of 10 times. If the number of times is greater than 10, the sample operation is no longer performed, and step 405 is performed. 0 Step 405: Calculate the characterization values of the response signals in the two time slots respectively.

When the standard and response signals are out of sync, waveform deviations as shown in Figure 6 or Figure 7 may occur. In Figure 6, the waveform of the response signal is shifted to the left in the square wave time slot of the standard clock. In the case of the sample, the reverse value of the response signal is collected in the negative direction, and in the positive direction, Collecting the same value as the standard clock; In Figure 7, the waveform of the response signal is shifted to the right within the square wave time slot of the standard clock, and similarly, the same as Figure 6 Sample results.

Calculate the characterization values of the response signals in the two divided time slots respectively. The calculation process is to perform the sum, difference, product, logarithm, and integral of all the sample values in each time slot. Or a combination of operations. Preferably, the sum values are summed to obtain the characterization values of the respective time slots.

In this embodiment, taking the waveform diagram of FIG. 6 as an example, since the response signal is shifted to the left, a positive 5 times sample value can be obtained in the time slot to the left of the square!0 wave, and the sample value is obtained. After the sum operation, the characterization value is obtained as SUMA. For the time slot with the shadow on the right side, the negative 的 sample value can be obtained. Since the response signal is in the negative direction, the obtained 釆 sample value is summed. After the operation, the characterization value is obtained, which is recorded as SUMB and is negative.

!5, step 407; if less, step 408;

Wherein, the predetermined threshold is a characterization difference obtained according to the divided time slots when the response signal is synchronized with the standard clock. The predetermined threshold value is related to the waveform of the response signal in the time slot. If the waveform of the response signal is divided into left and right symmetry when dividing the time slot, the difference value represented by subtracting the two time slots is The threshold is 0; if the time slot is divided, the waveform of the response signal is the origin Symmetrical, the characterization difference after subtracting through two time slots is not zero.

In this embodiment, the divided two time slots are equal, the number of times of each time slot is the same, and the response signal waveforms in the two time slots are mirror symmetrical, so the predetermined threshold is zero. For the judgment process, taking Figure 6 as an example, the response signal is just in the time slot to the left of the standard clock. At this time, the value of SUMB is a negative value. 5 The result of subtracting SUMB with SUMA is recorded as SUMC, and the value is subtracted by positive value. The result of the negative value must be a positive value greater than the threshold 0, indicating that the phase of the low frequency disturbance signal is offset to the right relative to the phase of the standard clock.

Step 407: Offset the phase of the low frequency disturbance clock to the left by a corresponding degree;

When the phase of the low frequency disturbance clock is adjusted to the left, it is necessary to obtain a 0 adjustment difference between the characteristic difference value and the predetermined threshold value, and move the corresponding degree by adjusting the difference value.

In this embodiment, if the obtained adjustment difference value SUMC corresponds to the phase difference of the response signal of the left part of the standard clock signal is 45 degrees, the phase of the low frequency disturbance signal is shifted to the left by 45 degrees, and the degree of the phase is Reduce it by 45 degrees.

Step 408: Determine whether the difference between the two representative values is less than a predetermined threshold. If it is less than 5, perform step 409; otherwise, indicate that no phase offset occurs, end the adjustment or re-execute step 401.

Taking Figure 7 as an example, if there is a case smaller than the threshold value, a waveform diagram as shown in Fig. 7 appears. At this time, the response signal of the standard clock waveform (ie, square wave) is negative in the unshaded area, so The sample result SUMA is a negative value, and the sampling result of the response signal in the shaded area is recorded as SUMB, and the SUMB is obtained as a positive value. SUMA minus SUMB results SUMC is a negative !0 value that must be less than the threshold 0.

Step 409: Offset the phase of the low frequency disturbance clock to the right by a corresponding degree.

When the phase of the low frequency disturbance clock is adjusted to the right, the adjustment difference between the characteristic difference value and the predetermined threshold value needs to be obtained, and the corresponding degree is moved by adjusting the difference value.

In this embodiment, the corresponding phase degree can be obtained according to the obtained difference SUMC, and the phase of the !5 low frequency disturbance signal is increased by the corresponding degree, so that the waveform of the low frequency disturbance signal is shifted to the right.

So far, the phase adjustment process in this embodiment ends.

It will be understood by those skilled in the art that all or part of the steps of the foregoing embodiments may be implemented by executing the instruction-related hardware by a program, and the program may be stored in a computer readable medium, the storage medium. Such as: ROM / RAM, disk, CD, etc. The above embodiment details the process of adjusting the phase difference. The following is a second embodiment of the apparatus for implementing the phase difference adjustment process. Referring to FIG. 8, the phase adjustment apparatus includes: a signal extraction unit 801. , a standard clock unit 802, a sample unit 803, an operation unit 804, a determination unit 805, and an adjustment unit 806, wherein:

a signal extraction unit 801, configured to obtain a response signal including a low frequency disturbance signal, and obtain a response signal having a frequency of the low frequency disturbance signal according to the response signal;

a standard clock unit 802, configured to divide a standard clock period of a predetermined length into two equal time slots and provide a standard clock signal; wherein, when the response signal is synchronized with the standard clock, the two time slots are The response signal waveform is symmetrical;

a sampling unit 803, configured to: in the time slot, the response signal of the low frequency disturbance signal frequency is sampled by the sampling clock; and acquiring the response signal in the divided two time slots The calculation unit 804 is configured to obtain a characterization value by using all the sample values in each time slot, obtain a characterization difference between the two characterization values, and obtain an adjustment between the characterization difference value and a predetermined threshold value. Difference

The determining unit 805 is configured to determine whether the adjusted difference exceeds a predetermined threshold, and obtain a judgment knot

5 fruit;

The adjusting unit 806 moves the phase of the low frequency disturbance signal by a corresponding angle according to the determination result and the adjustment difference.

The process by which the operation unit 804 obtains the characterization value by using all the sample values in each time slot includes:

!0 Combine all the sample values in each time slot with the sum, difference, product, logarithm, and integral mathematical operations or a combination of them to obtain the characterization value.

The adjusting unit 806 includes:

a first adjusting unit 807, configured to: when the determining result is that the difference is greater than the predetermined threshold, reduce a phase of the low frequency disturbance signal by a corresponding angle according to the difference;

The second adjustment unit 808 is configured to increase the phase of the low frequency disturbance signal by a corresponding angle according to the difference when the determination result is that the adjustment difference is less than the threshold.

It should be noted here that the functions of the determining unit 805 and the adjusting unit 806 can be integrated into one unit in practical applications.

The method and apparatus in embodiments of the present invention are capable of adjusting between a low frequency disturbance signal and a response signal The phase difference keeps the phase difference between the low frequency disturbance signal and the response signal synchronized. The characterization value can be obtained in a variety of ways, the calculation method is flexible, easy to implement, and the phase difference control precision is accurate.

The above-described phase adjustment device can be used in various types of electronic devices, such as in a light modulator, but is not limited to a light modulator. Referring now to FIG. 9 for an embodiment of the apparatus application and optical modulator of the present invention, FIG. 9 is a structural diagram of a light modulator including an input device 901, a bias voltage control device 902, and a phase. The adjusting device 903, the photoelectric conversion device 904, wherein the light modulator may be an MZ modulator.

An input device 901, configured to input a low frequency disturbance signal and an RF signal into the light modulator; 0 a photoelectric conversion device 904, configured to obtain a modulated optical response signal having a low frequency disturbance signal, and convert the optical response signal into a response Signal

The phase adjustment device 903 includes: a signal extraction unit 905, a standard clock unit 906, a sample unit 907, an operation unit 908, a determination unit 909, and an adjustment unit 910;

a signal extracting unit 905, configured to obtain, from the photoelectric conversion device 904, a response signal including the low frequency disturbance signal 5, and obtain a response signal having a frequency of the low frequency disturbance signal according to the response signal;

a standard clock unit 906, configured to divide a standard clock period of a predetermined length into two equal time slots and provide a standard clock signal; wherein, when the response signal is synchronized with the standard clock, the two time slots are The response signal waveform is symmetrical;

a sampling unit 907, configured to: in the time slot, the response signal of the low frequency disturbance signal frequency !0 is sampled by the sampling clock; in the divided two time slots, acquiring the response signal The operation unit 908 is configured to obtain a characterization value by using all the sample values in each time slot, obtain a characterization difference between the two characterization values, and obtain a relationship between the characterization difference value and a predetermined threshold value. Adjust the difference;

The determining unit 909 is configured to determine whether the adjusted difference exceeds a predetermined threshold, and obtain a judgment result;

!5 adjusting unit 910, moving the phase of the low frequency disturbance signal by a corresponding angle according to the determination result and the adjustment difference;

The bias voltage control device 902 is configured to increase or decrease the bias voltage by using the calculation result by performing synchronous demodulation calculation on the low frequency disturbance signal and the response signal.

The adjusting unit 910 includes: a first adjusting unit 911, configured to: when the determining result is that the adjustment difference is greater than the predetermined threshold, reduce a phase of the low frequency disturbance signal by a corresponding angle according to the difference;

The second adjusting unit 912 is configured to: when the determining result is that the adjustment difference is less than the predetermined threshold, increase a phase of the low frequency disturbance signal by a corresponding angle according to the difference.

In this embodiment, the phase difference can be adjusted without interruption; a control switch can also be added to perform the operation of adjusting the phase difference when the bias voltage is not stable.

The optical modulator in the embodiment of the invention can calculate the low frequency disturbance signal and the response signal, and use the calculation result to increase or decrease the bias voltage, so that the bias voltage and power of the light modulator operate at a stable working point, so that the output is stable. Optical modulation signal.

For those skilled in the art, the calculation process of the bias voltage control device can be implemented in various existing ways, such as calculating the deviation value of the bias voltage by the amplitude relationship of the low frequency disturbance signal and the response signal; The technique of calculating the deviation value of the bias voltage when the voltage is operated at MAX or MIN as shown in FIG. 1 to perform corresponding adjustment. These techniques can be phase controlled by the scheme in the embodiment of the present invention to achieve relatively stable control of the bias voltage.

For the methods, devices, and optical modulators set forth in the various embodiments of the present invention, any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention are intended to be included in the scope of the present invention. .

Claims

Rights request

A method for phase adjustment, comprising:

Obtaining a response signal including a low frequency disturbance signal, and obtaining a response signal having a frequency of the low frequency disturbance signal according to the response signal;

5 dividing a standard clock period of a predetermined length into two equal time slots, wherein the response signal of the low frequency disturbance signal frequency is sampled by the sample clock in the time slot; wherein the response signal is When the standard clock is synchronized, the waveforms of the response signals in the two time slots are symmetrical;

Obtaining a sample value of the response signal in the two time slots of the dividing;

The characterization value is obtained by using all the sample values in each time slot, and the characterization difference between the two characterization values is obtained.

0 value;

2. The method according to claim 1, wherein the process of obtaining the characterization value by using all the sample values in each time slot comprises:

5 Perform all the numerical values in each time slot for each of the sum, difference, product, logarithm, and integral arithmetic operations or a combination thereof to obtain the characterization value.

3. The method according to claim 1, wherein the step of moving the phase of the low frequency disturbance signal by a corresponding angle according to the adjustment difference comprises:

And when the characterization difference is greater than the predetermined threshold, reducing a phase of the low frequency disturbance !0 signal by a corresponding angle according to the adjustment difference;

When the characterization difference is less than the predetermined threshold, the phase of the low frequency disturbance signal is increased by a corresponding angle according to the adjustment difference.

4. The method according to claim 1, wherein the predetermined threshold is a characterization difference obtained when the response signal is synchronized with the standard clock.

!5

5. A phase adjustment device, comprising:

a standard clock unit, configured to divide a standard clock period of a predetermined length into two equal time slots and provide a standard clock signal; wherein, when the response signal is synchronized with the standard clock, the two times The waveform of the response signal in the gap is symmetrical;

a sampling unit, configured to: in the time slot, the response signal of the low frequency disturbance signal frequency is sampled by the sampling clock; and obtaining the sample value of the response signal in the divided two time slots And an operation unit, configured to obtain a characterization value by using all the sample values in each time slot, obtain a characterization difference between the two characterization values, and obtain an adjustment difference between the characterization difference value and a predetermined threshold value; ;

And an adjusting unit, configured to move a phase of the low frequency disturbance signal by a corresponding angle according to the adjustment difference.

6. The apparatus according to claim 5, wherein the calculating unit obtains the characterization value by using all the sample values in each time slot comprises:

0 All the sample values in each time slot are subjected to any of the mathematical operations of the sum, difference, product, logarithm, and integral, or a combination thereof to obtain a characterization value.

The device according to claim 5, wherein the adjusting unit comprises: a first adjusting unit, configured to: when determining that the adjusted difference is greater than the predetermined threshold, according to the difference Determining the phase of the low frequency disturbance signal by a corresponding angle;

And a second adjusting unit, configured to increase a phase of the low frequency disturbance signal by a corresponding angle according to the difference when determining that the adjustment difference is less than the predetermined threshold.

8. A light modulator, comprising:

An input device, configured to input a low frequency disturbance signal and a high frequency data RF signal into the light modulator; a photoelectric conversion device, configured to obtain a modulated optical response signal having a low frequency disturbance signal, and convert the !0 optical response signal into Response signal

Phase adjustment device, including:

a sampling unit, configured to: in the time slot, the response signal of the low frequency disturbance signal frequency is sampled by the sampling clock; and obtaining the sample value of the response signal in the divided two time slots An arithmetic unit for obtaining a characterization value using all the sample values in each time slot to obtain two characterizations Determining a difference between the values, obtaining an adjustment difference between the characteristic difference value and a predetermined threshold value; adjusting unit, configured to move a phase of the low frequency disturbance signal by a corresponding angle according to the adjustment difference value;

And a bias voltage control device configured to increase or decrease the bias voltage by using the calculation result by performing synchronous demodulation calculation on the low frequency disturbance signal and the response signal.

The light modulator according to claim 8, wherein the adjusting unit comprises: a first adjusting unit, configured to: when determining that the adjusted difference is greater than the predetermined threshold, according to the The difference reduces the phase of the low frequency disturbance signal by a corresponding angle;

a second adjusting unit, configured to: when determining that the adjustment difference is less than the predetermined threshold, increase a phase of the low frequency disturbance signal by a corresponding angle according to the difference.

10. The light modulator of claim 8, wherein the light modulator is a Mach-Zehnder modulator.