介绍了激光回馈的概念及其两种主要的理论研究模型:三镜腔模型和注入锁定模型。激光回馈干涉仪相位灵敏度与传统双光束干涉仪相当,且具有结构简单、紧凑、易准直、对激光器无特殊要求等突出优势。重点介绍了激光回馈干涉仪在位移、速度等参量测量及生物传感领域的发展应用。当被测表面为漫反射表面时,散斑的存在将导致自混合信号的振幅衰减,并引入随机相位误差。总结了自混合干涉系统中的散斑效应及改良技术手段,介绍了散斑效应在传感测量领域的发展应用。 The concept of laser feedback and its two main theoretical models are introduced: the three-cavity model and the injection locking model. The phase sensitivity of the laser-feedback interferometer is comparable to that of the traditional two-beam interferometer, and has the advantages of simple structure, compactness, easy collimation and no special requirement for the laser. The development and application of laser feedback interferometer in displacement and velocity measurement and biosensing are introduced. When the surface to be measured is a diffusely reflecting surface, the presence of speckle will cause the amplitude of the self-mixing signal to decay and introduce a random phase error. The speckle effect in self-mixing interference system and the improved technique are summarized. The development and application of speckle effect in the field of sensing measurement are introduced.