CN-122017516-A - Method and device for realizing human body safety measurement of crystal electro-optic coefficient

CN122017516ACN 122017516 ACN122017516 ACN 122017516ACN-122017516-A

Abstract

The invention discloses a method and a device for realizing human body safety measurement of crystal electro-optic coefficient, belonging to the technical field of photoelectric measurement, wherein the method comprises the steps of constructing a crystal electro-optic coefficient measuring light path, and sequentially arranging a wavelength tunable light source, a polarizer, a true zero-order half wave plate, an electro-optic crystal to be measured, an analyzer and a power meter along the propagation direction of the light path; and adjusting the wavelength of the light source and the voltage on the electro-optic crystal to be tested, judging the extinction state by a power meter, and fitting according to the wavelength voltage data corresponding to a plurality of groups of extinction states to obtain the electro-optic coefficient of the electro-optic crystal to be tested. The electro-optic coefficient precision obtained by fitting multiple groups of data is equivalent to that of the traditional high-voltage method, and meanwhile, only extremely small phase delay is generated each time in the repeated extinction process, so that the measurement voltage is greatly reduced, and the potential safety hazard and the crystal breakdown risk caused by high voltage are effectively avoided.

Inventors

WANG ZHENGPING
YU HAOHAI
HUANG JUNRU
LIU GUOWEI
REN HONGKAI

Assignees

山东大学

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. A method for realizing human body safety measurement of crystal electro-optic coefficients, which is characterized by comprising the following steps: The method comprises the steps of constructing a crystal electro-optic coefficient measuring light path, wherein the crystal electro-optic coefficient measuring light path comprises a wavelength tunable light source, a polarizer, a true zero-order half-wave plate, an electro-optic crystal to be measured, an analyzer and a power meter which are sequentially arranged along the propagation direction of the light path; step two, connecting the electro-optic crystal to be tested with an adjustable direct current power supply; Regulating the output wavelength of the wavelength tunable light source, regulating the voltage applied by the adjustable direct current power supply to the electro-optical crystal to be tested when the output wavelength is fixed until the reading of the power meter reaches a minimum value, judging that a measuring light path is in an extinction state, and recording a group of wavelength values and voltage values at the moment; step four, repeating the step three to obtain a plurality of groups of wavelength values and voltage values; And fifthly, performing linear fitting on the obtained multiple groups of wavelength values and voltage values, and obtaining the electro-optic coefficient of the electro-optic crystal to be tested according to the fitting result.
2. The method for safely measuring the electro-optic coefficient of a crystal according to claim 1, wherein in the third step, when the reading of the power meter reaches a minimum value, the phase difference generated by the electro-optic effect of the electro-optic crystal to be measured due to the applied voltage compensates the chromatic dispersion phase difference of the half-wave plate due to the wavelength change, so that the total phase difference of the crystal electro-optic coefficient measuring optical path is 。
3. The method of claim 1, wherein in the crystal electro-optic coefficient measuring light path constructed in the first step, the highest output voltage of the adjustable dc low-voltage power supply is not higher than 36V.
4. The method for realizing human body safety measurement of crystal electro-optic coefficient according to claim 1, wherein in the crystal electro-optic coefficient measuring light path constructed in the first step, the polarizer and the polarization analyzer are parallel to each other in the vibration transmission direction.
5. The method for realizing human body safety measurement of crystal electro-optic coefficient according to claim 1, wherein the electro-optic crystal to be measured comprises one of BBO crystal, DKDP crystal or KDP crystal.
6. The method for realizing human body safety measurement of crystal electro-optic coefficient according to claim 5, wherein when the electro-optic crystal to be measured is a BBO crystal, the transverse electro-optic coefficient of the electro-optic crystal to be measured is measured; and when the electro-optical crystal to be measured is a DKDP crystal or a KDP crystal, measuring the longitudinal electro-optical coefficient of the electro-optical crystal to be measured.
7. The device for realizing human body safety measurement of the crystal electro-optic coefficient is characterized by comprising a crystal electro-optic coefficient measuring light path and a data control processing module, wherein the crystal electro-optic coefficient measuring light path comprises a wavelength tunable light source, a polarizer, a true zero level half wave plate, an electro-optic crystal to be measured, an analyzer and a power meter which are sequentially arranged along the propagation direction of the light path; The data control processing module is respectively connected with the wavelength tunable light source, the adjustable direct current low-voltage power supply and the power meter, and is used for respectively adjusting the wavelength of the wavelength tunable light source and the voltage of the adjustable direct current low-voltage power supply, measuring the extinction state of the light path by taking the minimum value of the power meter reading as a criterion when the wavelength is fixed, recording a plurality of groups of wavelength and voltage data, and simultaneously carrying out linear fitting according to the recorded plurality of groups of wavelength and voltage data to obtain the electro-optic coefficient of the electro-optic crystal to be tested.
8. The apparatus for achieving a human safety measure of the electro-optic coefficient of crystals of claim 7, wherein the wavelength of said wavelength tunable light source is continuously tuned in the range of 500-560 nm.
9. A device for achieving a safe measurement of the electro-optic coefficient of a crystal of a human body as recited in claim 7, wherein said true zero-order half waveplate comprises a true zero-order half waveplate made of quartz.
10. The apparatus for realizing human body safety measurement of electro-optic coefficient of crystal according to claim 7, wherein said electro-optic crystal to be measured is processed into hexahedral shape.

Description

Method and device for realizing human body safety measurement of crystal electro-optic coefficient Technical Field The invention relates to the technical field of photoelectric measurement, in particular to a method and a device for realizing human body safety measurement of a crystal electro-optic coefficient. Background The electro-optic crystal is a core material of a high-speed electro-optic switch, a modulator and a pulse laser, and the electro-optic coefficient directly determines the performance and stability of the device and is a key parameter for measuring the quality of the material. Currently, methods for measuring the electro-optic coefficient of crystals are developed by a half-wave voltage method, an ellipsometer method, an interference compensation method and an electro-optic effect comparison method. The ellipsometry device is complex, has high requirements on equipment precision, is not easy to reach domestic equipment, has high detection cost and is less to use. The interference compensation method and the electro-optical effect comparison method are both indirect measurement methods, and based on the inverse piezoelectric effect or the electro-optical effect of the reference sample, the measurement result is seriously dependent on the type and quality of the reference sample, and has limited accuracy and insufficient reliability. In the whole, the half-wave voltage method is still the most direct, most common, most mature and most authoritative measuring method for the electro-optic coefficient, and has the advantages of economy, accuracy, convenience and the like. The most basic principle of the half-wave voltage method is to generate voltage required by lambda/2 optical path difference (namely phase difference) in an orthogonal polarization optical path, and calculate an electro-optic coefficient by combining a theoretical formula. Most electro-optical crystals have half-wave voltages as high as thousands of volts, have severe requirements on high-voltage power supply performance, not only increase equipment cost, but also bring strict requirements on measurement environment, and form serious potential safety hazards for measurement personnel. For crystals with smaller electro-optic coefficients, a high voltage of ten thousand volts is required, and for some crystals with smaller electro-optic coefficients or low resistivity, the crystals are easy to generate heat or break down after the high voltage is increased, and even the results are difficult to measure by using a half-wave voltage method. In summary, how to develop a new electro-optic coefficient measurement method, which has the characteristics of simplicity, economy, directness and accuracy, and can strictly control the working voltage below 36V, which is safe for human body, has become a problem to be solved in the field of electro-optic crystal research. Disclosure of Invention The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method and apparatus for realizing a human body safety measurement of the electro-optic coefficient of crystals that overcomes or at least partially solves the above problems. In order to achieve the above purpose, the present invention adopts the following technical scheme: in a first aspect, an embodiment of the present invention provides a method for implementing human body safety measurement of a crystal electro-optic coefficient, including the steps of: The method comprises the steps of constructing a crystal electro-optic coefficient measuring light path, wherein the crystal electro-optic coefficient measuring light path comprises a wavelength tunable light source, a polarizer, a true zero-order half-wave plate, an electro-optic crystal to be measured, an analyzer and a power meter which are sequentially arranged along the propagation direction of the light path; step two, connecting the electro-optic crystal to be tested with an adjustable direct current power supply; Regulating the output wavelength of the wavelength tunable light source, regulating the voltage applied by the adjustable direct current power supply to the electro-optical crystal to be tested when the output wavelength is fixed until the reading of the power meter reaches a minimum value, judging that a measuring light path is in an extinction state, and recording a group of wavelength values and voltage values at the moment; step four, repeating the step three to obtain a plurality of groups of wavelength values and voltage values; And fifthly, performing linear fitting on the obtained multiple groups of wavelength values and voltage values, and obtaining the electro-optic coefficient of the electro-optic crystal to be tested according to the fitting result. Further, in the third step, when the reading of the power meter reaches a minimum value, the phase difference generated by the electro-optic effect of the electro-optic crystal to be measured due to t