多模激光自混合效应的理论与应用研究

Firstly, Based on theory of the self-mixing interference effects of single-mode laser, we studied the theoretic model of self-mixing nterference effects of multi-mode laser and explained the phenomena in this instance. Besides, we made numerical stimulations for this model. For the.question of stabilization of the self-mixing interference system, A mathematics model of the.system is established based on a equivalent three-mirrors cavity model. The boundary of the single solution and multiple ones are given by solving the phase equation of the model. Thus the optical feedback level in this system with a stable operating can be determined theoretically. Experimentally, the multi-mode self-mixing signals of external cavities with different initial.lengths are observed. In this condition, the interference signal can be observed easily from oscillograph. The SNR is higher than that in the state of single-mode and the initial length of.external cavity can be longer. The signals of self-mixing interference effects in the Diode Pumped Solid-State Laser are also observed and the conclusions we got develop the theory of self-mixing.interference. When processing the displacement interference signal, we refer to the method of FFT used frequently in conventional interference signal processing to improve the performance and.accuracy of measurement. A self-mixing interference structure including a reference arm is proposed to eliminate errors caused by nonlinear modulation of laser frequency. But it applies to.distance measurement.

研究多模激光状态下激光自混和效应理论，解释复杂的物理现象，分析多重光反馈的激光自混合信号波形，探索新型非接触、大量程、无导轨、高分辨率位移光感器方案。在很多应用场合可以取代结构庞大、光路复杂、敏感于准直的传统干涉测量仪；基于半导体激光的自混合测量系统，由于结构紧凑、单光路，可以在单片导体芯片上集成微传感系统。