CN104132798A - Y-waveguide integrated optics phase modulator modulation factor measurement device and method - Google Patents

Abstract

The invention provides a device and method for measuring the modulation coefficient of a Y-waveguide integrated optical phase modulator. The device includes a wide-spectrum light source, a circulator, a Y-waveguide integrated optical phase modulator, a polarization beam splitter, a polarization-maintaining delay fiber, and a Faraday rotator. Reflector, signal generator, photodetector and oscilloscope; Y-waveguide integrated optical phase modulator modulation coefficient measurement device and method provided by the invention, for mastering the generation mechanism and suppression method of the transformation ratio temperature error of optical fiber current transformer, improve the optical fiber The temperature environment adaptability and long-term operation stability of current transformers are of great significance.

Description

Device and method for measuring modulation coefficient of Y waveguide integrated optical phase modulator

technical field

The invention relates to a device and a method, in particular to a device and a method for measuring the modulation coefficient of a Y waveguide integrated optical phase modulator.

Background technique

The Y-waveguide integrated optical phase modulator uses lithium niobate (LiNbO ₃ ) as the base material, forms a waveguide through the proton exchange process, integrates the three functions of polarization, light splitting and phase modulation, reduces the number of devices, and enhances the device It is the core device for digital closed-loop fiber optic current transformer to achieve high precision and large dynamic range measurement.

The digital closed-loop fiber optic current transformer based on the Faraday effect uses the Y waveguide integrated optical phase modulator to realize bias modulation and feedback control, combined with digital lock-in amplification technology, by detecting two beams of orthogonal circularly polarized light with opposite rotation in the sensing fiber It has the advantages of high measurement accuracy, wide frequency response range, large dynamic range, simple insulation, no ferromagnetic resonance, digital output, small size, light weight, etc. In smart substations, Both UHV AC and DC transmission fields have important applications.

The temperature stability of measurement accuracy is one of the important indicators for evaluating the performance of optical fiber current transformers, and it is also the main factor that currently limits the large-scale application of optical fiber current transformers. The Y waveguide integrated optical phase modulator is located in the feedback channel of the optical fiber current transformer digital closed-loop signal detection system. Its modulation coefficient is defined as the modulation phase added to the transmitted light wave by the unit modulation voltage, which is an important part of the feedback gain. When the ambient temperature changes, the modulation coefficient will change, and the transformation ratio of the transformer will also change accordingly, resulting in a transformation ratio error and affecting the measurement accuracy of the transformer.

Contents of the invention

The invention provides a modulation coefficient measurement device and method of a Y-waveguide integrated optical phase modulator, which can improve the temperature environment adaptability and long-term operation stability of the optical fiber current transformer for mastering the generation mechanism and suppression method of the transformation ratio temperature error of the optical fiber current transformer Sex matters.

In order to realize the above-mentioned purpose of the invention, the present invention takes the following technical solutions:

The invention provides a modulation coefficient measuring device of a Y-waveguide integrated optical phase modulator, said device comprising a wide-spectrum light source, a circulator, a Y-waveguide integrated optical phase modulator, a polarization beam splitter, a polarization-maintaining delay fiber, and a Faraday rotation optical reflector , a signal generator, a photodetector, and an oscilloscope; the light wave emitted by the broadband light source passes through a circulator, is polarized by a Y waveguide integrated optical phase modulator, and is split into two beams of linearly polarized light, and the two beams of linearly polarized light are polarized respectively After the beam splitter combines the light, it is transmitted along the polarization-maintaining delay fiber, and returns along the original path after being reflected by the Faraday rotation mirror; the two beams of linearly polarized light returning along the original path interfere after being analyzed by the Y-waveguide integrated optical phase modulator, resulting in Interfering light intensity: the signal generator generates a sawtooth wave modulation signal and transmits it to the Y-waveguide integrated optical phase modulator, the photodetector converts the interference light intensity into a voltage signal, and the oscilloscope displays the corresponding waveform.

The wide-spectrum light source is a light source module with its own drive circuit, and adopts a superluminescent light-emitting diode or an erbium-doped optical fiber light source.

The circulator is a single-mode fiber circulator or a polarization-maintaining fiber circulator.

The polarization beam splitter is a polarization-maintaining fiber polarization beam splitter, and its input fiber and output pigtail are panda-type polarization-maintaining fibers;

The polarization-maintaining delay fiber is a panda-type polarization-maintaining fiber with a length greater than 50m.

The optical rotation angle of the Faraday rotation reflector is 45°, the error is less than ±1°, and the reflectivity is greater than 90%; the photodetector adopts a detector integrated component with a current-voltage conversion circuit.

The linearly polarized light polarized by the Y-waveguide integrated optical phase modulator is split into a first linearly polarized light and a second linearly polarized light, and the polarization directions of the first linearly polarized light and the second linearly polarized light are the same.

The first linearly polarized light and the second linearly polarized light are combined by the polarization beam splitter and then transmitted along the fast axis and slow axis of the polarization-maintaining delay fiber, and returned along the original path after being reflected by the Faraday rotation mirror, and the polarization modes are mutually exchanged. In other words, the first linearly polarized light transmitted along the fast axis of the polarization maintaining delay fiber is now transmitted along the slow axis, and the second linearly polarized light transmitted along the slow axis of the polarization maintaining delay fiber is now transmitted along the fast axis; the first linearly polarized light and the second linearly polarized light The two linearly polarized lights are split by the polarization beam splitter and then enter the Y-waveguide integrated optical phase modulator for analysis and interference.

The present invention also provides a method for measuring the modulation coefficient of the Y-waveguide integrated optical phase modulator by using a Y-waveguide integrated optical phase modulator modulation coefficient measuring device, the method comprising the following steps:

Step 1: Calculate the modulation voltage of the Y-waveguide integrated optical phase modulator;

Step 2: Calculate the phase difference between the two beams of linearly polarized light;

Step 3: Calculate the output voltage of the photodetector;

Step 4: Determine the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator.

In the step 1, the modulation voltage of the Y-waveguide integrated optical phase modulator is represented by V _m (t), which has:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; kT</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>& \mathrm{<span\; class="notranslate">\; kT</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; T</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ;</span>& \mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; T</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Among them, V _r and T are the voltage amplitude and period of the sawtooth wave, k=0, 1, 2, . . .

In the step 2, the phase difference between the first linearly polarized light and the second linearly polarized light is used Indicates that there are:

Among them, K is the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator, τ is the time difference of the light wave passing through the Y-waveguide integrated optical phase modulator twice, and V _m (t) and V _m (t-τ) are respectively t and the modulation voltage at time t-τ, is the birefringence modulation phase produced by _Vr , and

In the step 3, the output voltage of the photodetector is represented by _Vp , which has:

Among them, η is the product of photodetector responsivity and transimpedance, α is the optical path loss, and _Ix is the light intensity of the X-polarized component in the output light wave of the light source.

Described step 4 comprises the following steps:

Step 4-1: when calculating the amplitude e=0 of the square wave signal output by the photodetector, satisfy the formula (4) The smallest positive solution is:

The smallest positive solution that satisfies formula (4) Corresponding V _r =V _2π , V _2π is the full-wave voltage of the Y-waveguide integrated optical phase modulator;

Step 4-2: Calculate the birefringence modulation coefficient K of the Y-waveguide integrated optical phase modulator, which is:

Compared with prior art, the beneficial effect of the present invention is:

1. Y waveguide integrated optical phase modulator and polarization maintaining delay fiber for two orthogonal polarization mode transmission, the optical path structure is completely reciprocal, and has strong immunity to external environmental interference;

2. The test can be completed by using a general signal generator and an oscilloscope, and the operation is simple, convenient and efficient;

3. It is of great significance to master the generation mechanism and suppression method of the transformation ratio temperature error of the optical fiber current transformer, and to improve the temperature environment adaptability and long-term operation stability of the optical fiber current transformer.

Description of drawings

Fig. 1 is a structural principle diagram of a Y-waveguide integrated optical phase modulator birefringence modulation coefficient measuring device in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the measurement principle of the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator in the embodiment of the present invention (V _r ≠ V _2π );

Fig. 3 is a schematic diagram of the measurement principle of the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator in the embodiment of the present invention (V _r =V _2π ).

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Fig. 1, the present invention provides a kind of Y-waveguide integrated optical phase modulator modulation coefficient measurement device, described device comprises broadband light source, circulator, Y-waveguide integrated optical phase modulator, polarization beam splitter, polarization maintaining delay fiber, Faraday rotation mirror, signal generator, photodetector and oscilloscope; the light wave emitted by the broadband light source passes through the circulator, is polarized by the Y waveguide integrated optical phase modulator, and splits into two beams of linearly polarized light, two beams of linearly polarized light The light is combined by the polarization beam splitter and then transmitted along the polarization maintaining delay fiber, and returned along the original path after being reflected by the Faraday rotation mirror; the two linearly polarized lights returned along the original path are analyzed by the Y waveguide integrated optical phase modulator Interference occurs to generate interference light intensity; the signal generator generates a sawtooth wave modulation signal and applies it to the Y waveguide integrated optical phase modulator, and the photodetector converts the interference light intensity into a voltage signal, which is displayed by the oscilloscope waveform.

The wide-spectrum light source is a light source module with its own drive circuit, and adopts a superluminescent light-emitting diode or an erbium-doped optical fiber light source.

The circulator is a single-mode fiber circulator or a polarization-maintaining fiber circulator.

The polarization beam splitter is a polarization-maintaining fiber polarization beam splitter, and its input fiber and output pigtail are panda-type polarization-maintaining fibers;

The polarization-maintaining delay fiber is a panda-type polarization-maintaining fiber with a length greater than 50m.

The optical rotation angle of the Faraday rotation reflector is 45°, the error is less than ±1°, and the reflectivity is greater than 90%; the photodetector adopts a detector integrated component with a current-voltage conversion circuit.

The linearly polarized light polarized by the Y-waveguide integrated optical phase modulator is split into a first linearly polarized light and a second linearly polarized light, and the polarization directions of the first linearly polarized light and the second linearly polarized light are the same.

The first linearly polarized light and the second linearly polarized light are combined by the polarization beam splitter and then transmitted along the fast axis and slow axis of the polarization-maintaining delay fiber, and returned along the original path after being reflected by the Faraday rotation mirror, and the polarization modes are mutually exchanged. In other words, the first linearly polarized light transmitted along the fast axis of the polarization maintaining delay fiber is now transmitted along the slow axis, and the second linearly polarized light transmitted along the slow axis of the polarization maintaining delay fiber is now transmitted along the fast axis; the first linearly polarized light and the second linearly polarized light The two linearly polarized lights are split by the polarization beam splitter and then enter the Y-waveguide integrated optical phase modulator for analysis and interference.

The present invention also provides a method for measuring the modulation coefficient of the Y-waveguide integrated optical phase modulator by using a Y-waveguide integrated optical phase modulator modulation coefficient measuring device, the method comprising the following steps:

Step 1: Calculate the modulation voltage of the Y-waveguide integrated optical phase modulator;

Step 2: Calculate the phase difference between the two beams of linearly polarized light;

Step 3: Calculate the output voltage of the photodetector;

Step 4: Determine the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator.

In the step 1, the modulation voltage of the Y-waveguide integrated optical phase modulator is represented by V _m (t), which has:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; kT</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>& \mathrm{<span\; class="notranslate">\; kT</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; T</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ;</span>& \mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; T</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Wherein, V _r and T are the voltage amplitude and period of the sawtooth wave, k=0, 1, 2, ..., and its waveform is shown as signal 1 in Fig. 2 .

In the step 2, the phase difference between the first linearly polarized light and the second linearly polarized light is used Indicates that there are:

Among them, K is the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator, τ is the time difference of the light wave passing through the Y-waveguide integrated optical phase modulator twice, and V _m (t) and V _m (t-τ) are respectively t and the modulation voltage at time t-τ, is the birefringence modulation phase produced by _Vr , and The waveform is shown as signal 2 in Fig. 2 .

In the step 3, the output voltage of the photodetector is represented by _Vp , which has:

Wherein, η is the product of photodetector responsivity and transimpedance, α is optical path loss, and I _x is the light intensity of X polarization component in the light source output light wave; The output voltage V _p waveform of photodetector is as the square wave in accompanying drawing 2 Signal 3 is shown.

Described step 4 comprises the following steps:

Step 4-1: when calculating the amplitude e=0 of the square wave signal output by the photodetector, satisfy the formula (4) The smallest positive solution is:

The smallest positive solution that satisfies formula (4) Corresponding V _r =V _2π , V _2π is the full-wave voltage of the Y-waveguide integrated optical phase modulator; the corresponding waveform is shown in Fig. 3 .

Step 4-2: Calculate the birefringence modulation coefficient K of the Y-waveguide integrated optical phase modulator, which is:

Example

The wide-spectrum light source is a light source module with its own drive circuit, which can be a superluminescent light-emitting diode or an erbium-doped fiber light source; the circulator is a single-mode fiber circulator or a polarization-maintaining fiber circulator; the Y waveguide under test integrates an optical phase The input pigtail of the modulator is automatically fused to the output pigtail of the single-mode fiber circulator, or 0° to the axis of the output pigtail of the polarization-maintaining fiber circulator. The output pigtail of the modulator is connected to the input of the polarization beam splitter The pigtail is spliced at 0° on the axis; the polarization beam splitter is a polarization maintaining fiber polarization beam splitter, and its input and output pigtails are Panda-type polarization-maintaining fiber; the polarization-maintaining delay fiber is a Panda-type polarization-maintaining fiber, and its length is about 100m, which determines the transit time τ=1μs; the optical rotation angle of the Faraday optical mirror is 45°, the error is less than ±1°, and the reflectivity is greater than 90%; the photodetector adopts the detector integrated component with a current-voltage conversion circuit ; Signal generators and oscilloscopes are common instruments.

The measurement steps of the modulation coefficient of the Y waveguide integrated optical phase modulator are as follows:

(1) The sawtooth wave modulation signal 1 of cycle T=10 μ s is applied on the Y-waveguide integrated optical phase modulator by the signal generator, meanwhile, the output of the photodetector is observed with an oscilloscope;

(2) adjust the amplitude of the sawtooth signal 1, when the amplitude e of the output signal 3 of the photodetector gradually decreases until it becomes signal 6, record the amplitude V _2π of the sawtooth signal 4 now;

(3) Calculate the modulation coefficient of the modulator according to formula (5).

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those of ordinary skill in the art can still modify or equivalently replace the specific implementation methods of the present invention with reference to the above embodiments. Any modifications or equivalent replacements departing from the spirit and scope of the present invention are within the protection scope of the claims of the pending application of the present invention.

Claims (12)

1. A Y-waveguide integrated optical phase modulator modulation factor measuring device is characterized in that: the device includes a wide-spectrum light source, a circulator, a Y-waveguide integrated optical phase modulator, a polarization beam splitter, a polarization-maintaining delay fiber, a Faraday Optically rotating mirror, signal generator, photodetector and oscilloscope; the light wave emitted by the broadband light source passes through the circulator, is polarized by the Y waveguide integrated optical phase modulator, and splits the light into two beams of linearly polarized light, and two beams of linearly polarized light After being combined by the polarization beam splitter, the light is transmitted along the polarization-maintaining delay fiber, and then returned along the original path after being reflected by the Faraday rotation mirror; the two beams of linearly polarized light returned along the original path are analyzed by the Y-waveguide integrated optical phase modulator and then generated Interference to generate interference light intensity; the signal generator generates a sawtooth wave modulation signal applied to the Y waveguide integrated optical phase modulator, the photodetector converts the interference light intensity into a voltage signal, and the corresponding waveform is displayed by the oscilloscope . 2. The Y-waveguide integrated optical phase modulator modulation coefficient measuring device according to claim 1, characterized in that: the broadband light source is a light source module with its own drive circuit, and adopts a superluminescent light-emitting diode or an erbium-doped optical fiber light source. 3. The device for measuring the modulation coefficient of the Y-waveguide integrated optical phase modulator according to claim 1, wherein the circulator is a single-mode fiber circulator or a polarization-maintaining fiber circulator. 4. Y-waveguide integrated optical phase modulator modulation factor measurement device according to claim 1, is characterized in that: described polarization beam splitter is polarization maintaining fiber polarization beam splitter, and its input optical fiber and output pigtail are panda type polarization maintaining fiber; The polarization-maintaining delay fiber is a panda-type polarization-maintaining fiber with a length greater than 50m. 5. Y-waveguide integrated optical phase modulator modulation coefficient measurement device according to claim 1, is characterized in that: the optical rotation angle of described Faraday rotation reflector is 45 °, and error is less than ± 1 °, and reflectivity is greater than 90%; The photodetector adopts a detector integrated component with a current-voltage conversion circuit. 6. Y-waveguide integrated optical phase modulator modulation factor measuring device according to claim 1, is characterized in that: the linearly polarized light splitting through Y-waveguide integrated optical phase modulator polarized is the first linearly polarized light and the second linearly polarized light light, the polarization directions of the first linearly polarized light and the second linearly polarized light are the same. 7. The Y-waveguide integrated optical phase modulator modulation factor measuring device according to claim 6, characterized in that: the first linearly polarized light and the second linearly polarized light are combined by a polarization beam splitter and then along the polarization-maintaining delay fiber The fast axis and the slow axis of the polarization maintaining delay fiber are transmitted along the original path after being reflected by the Faraday rotation mirror, and the polarization mode is exchanged. The second linearly polarized light transmitted along the slow axis of the delay fiber is now transmitted along the fast axis; the first linearly polarized light and the second linearly polarized light are split by the polarization beam splitter and then enter the Y waveguide integrated optical phase modulator for analysis and interference. 8. A method for measuring the Y-waveguide integrated optical phase modulator modulation coefficient using the Y-waveguide integrated optical phase modulator modulation coefficient measuring device described in any one of claims 1-7, is characterized in that: the method comprises the following step: Step 1: Calculate the modulation voltage of the Y-waveguide integrated optical phase modulator; Step 2: Calculate the phase difference between the two beams of linearly polarized light; Step 3: Calculate the output voltage of the photodetector; Step 4: Determine the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator. 9. the method for measuring Y waveguide integrated optical phase modulator modulation coefficient according to claim 8, is characterized in that: in described step 1, the modulation voltage of Y waveguide integrated optical phase modulator uses V _m (t) Indicates that there are: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; kT</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>& \mathrm{<span\; class="notranslate">\; kT</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; T</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ;</span>& \mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; T</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ Among them, V _r and T are the voltage amplitude and period of the sawtooth wave, k=0, 1, 2, . . . 10. the method for measuring Y-waveguide integrated optical phase modulator modulation factor according to claim 8, is characterized in that: in described step 2, the phase difference between the first linearly polarized light and the second linearly polarized light is used Indicates that there are: Among them, K is the birefringence modulation coefficient of the Y-waveguide integrated optical phase modulator, τ is the time difference of the light wave passing through the Y-waveguide integrated optical phase modulator twice, and V _m (t) and V _m (t-τ) are respectively t and the modulation voltage at time t-τ, is the birefringence modulation phase produced by _Vr , and 11. the method for measuring Y-waveguide integrated optical phase modulator modulation factor according to claim 8, is characterized in that: in described step 3, the output voltage of photodetector is expressed with V _p , has: Among them, η is the product of photodetector responsivity and transimpedance, α is the optical path loss, and _Ix is the light intensity of the X-polarized component in the output light wave of the light source. 12. The method for measuring the modulation coefficient of Y waveguide integrated optical phase modulator according to claim 8, characterized in that: said step 4 comprises the following steps: Step 4-1: when calculating the amplitude e=0 of the square wave signal output by the photodetector, satisfy the formula (4) The smallest positive solution is: The smallest positive solution that satisfies formula (4) Corresponding V _r =V _2π , V _2π is the full-wave voltage of the Y-waveguide integrated optical phase modulator; Step 4-2: Calculate the birefringence modulation coefficient K of the Y-waveguide integrated optical phase modulator, which is: