回顾了一种全新结构的干涉仪—自混合干涉仪(SMI)的发展情况。SMI由于其在激光器外部无需任何光学元件且应用范围广泛而倍受关注。SMI可用于测量与光路长度有关的一些量(如位移、小幅度振动、速度)，也可用于测量弱光的回波(即回波损耗和隔离因子的测量)并可表征与介质相互作用特性相关的物理参数(如激光线宽、相干长度以及α因子等)。SMI是一种相干探测方法，其工作在靠近接收场的量子极限处，目前对散射目标物的最小探测幅值可达20 pm/Hz甚至更高，使用角锥棱镜使其计数步长为半波长，在动态范围为2 m时其分辨率约为05 μm。另外，SMI结构紧凑、易于现场安装且可用于MEMS测试、旋转机械振动测试和生物运行测试等各种实验。

This paper reviews the development of a new configuration of interferometry, Self-mixing Interferometry(SMI). SMI is attractive because it doesn′t require any optical part external to the laser and can be employed in a variety of measurements, ranging from the traditional measurements related to optical path length like displacements, small-amplitude vibrations, velocity; to sensing of weak optical echoes, like return loss and isolation factor measurements; and also to a special feature for the interaction with the medium, measurements of physical parameters, like laser line width, coherence length, and the alfa factor. Because it is also a coherent detection scheme, the SMI operation is close to the quantum limit of received field and the minimum detectable amplitudes of 20 pm/Hz or better are currently achieved upon operation on diffusive targets, whereas a corner cube allows half-wavelength counting mode or 05 μm resolution on a dynamic range up to 2 m. SMI has a compact setup, and is easy to deploy in the field and can interface a variety of experiments from MEMS testing to rotating machine vibration testing to pickup of biological motility as described in the paper.