基于相位凝固技术的激光反馈干涉系统

Laser Feedback Interference System Based on Phase-Freezing Technology

基于相位凝固技术的激光反馈干涉术,为验证其可行性及测量分辨率,设计了微位移测量验证系统。在系统中利用相位调制器进行外腔相位调制,采用相位凝固技术进行采样及解调,重构出外部目标物的位移信息。建立了测量系统的模型,进行了基于相位凝固技术的调制解调算法仿真及位移测量验证实验。实验验证了仿真的正确性和系统的可行性,通过比较外部目标物的实际位移与系统重构位移结果,得出测量峰谷值相对误差小于3%。研究表明,此测量方法能够准确地测量出外部目标物的位移信息,可有效提高系统测量分辨率,并可实现微位移的实时测量。

A laser feedback interferometry combined with phase-freezing technology is researched. To verify the technology and its measurement resolution, a micro-displacement measurement system is designed. In the system, phase modulator is added to modulate the external cavity phase and phase-freezing technology is used for sampling and demodulation to reconstruct the displacement information of the external target. Measurement system model is established. Modulation-demodulation algorithm simulation based on phase-freezing technology and the displacement measurement experiment are made. Comparing the actual displacement of the external target and the system reconstruction result, the accuracy of simulation and the feasibility of system are verified. The measurement peak- valley （PV） value relative error is less than 3%. It is drawn that the method can effectively improve the measurement resolution of system and achieve the real-time measurement of micro-displacement.