A device and method for measuring the FSR of a multi-longitudinal-mode laser resonator by using a large-amplitude laser self-mixing vibration signal

Abstract

The invention relates to the technical field of laser devices, in particular to a device and method for measuring a multi-longitudinal mode laser resonant cavity FSR by large-amplitude laser self-mixing vibration signals. The device comprises a multi-longitudinal mode laser device, a vibrating target, a transmission mechanism, a motor, a signal generator, a beam splitter, a photoelectric detector,a signal preprocessing unit and a signal processing unit, the multi-longitudinal mode laser device emits laser to the vibrating target, by the signal generator, the motor and the transmission mechanism, the vibrating target linearly moves in a reciprocating manner, while linearly moving in a reciprocating manner, the vibrating target receives laser emitted from the multi-longitudinal mode laser device and feeds back the laser into a resonant cavity of the multi-longitudinal mode laser device to form the laser self-mixing vibration signals, the beam splitter splits the self-mixing signals to the photoelectric detector, and the output end of the photoelectric detector is successively connected with the signal preprocessing unit and the signal processing unit. Non-contact real-time high-precision measurement can be realized, the measurement device is simple in structure, measurement response speed is high, and measurement precision is also high.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a device and method for measuring the FSR of a multi-longitudinal-mode laser resonator by using a large-amplitude laser self-mixing vibration signal. Background technique [0002] Due to its inherent high brightness, high monochromaticity, high directivity and high coherence and other excellent characteristics, lasers are widely used in medical, communication, industrial and national defense and other fields. As the core component of the laser, the health monitoring of the laser resonator is an important part of maintaining the good operation of the laser. Since the indicators that affect the health of the laser resonator mainly include the free spectral region of the laser resonator (FSR for short) and the temperature of the laser resonator cavity, during the operation of the laser, the monitoring of the FSR of the laser resonator and the temperature of the laser resonator cavity...

AI Technical Summary

Problems solved by technology

[0004] 1. The method of directly observing the longitudinal mode spacing with a spectrometer, but this method is limited by the wavelength resolution of the spectrometer, and has problems such as low measurement resolution and sensitivity, low measurement accuracy, and high price;

[0005] 2. The method of measuring FSR by combining scanning FP and MZ interferometer and spectrum analyzer, but this method not only needs to combine large-scale instruments and equipment, but also is easily limited by the bandwidth of PD, the structure of the measurement system is complex, and the cost is high

[0006] Therefore, the above-mentioned traditional method of measuring the FSR of a laser resonator is not conducive to popularization and application, and is not suitable as a universal measurement method for monitoring FSR

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