干涉技术是测量微小光学相移或光程差最常用而且最灵敏的方法之一。常用的直接宽带、直流探测方法由于方法本身和技术条件限制,能探测到的最小光强相对变化(△I/I)_(min)约为10~(-4)[1].相应地能达到的光学相移测量灵敏度(△Φ)_(min)也在10~(-4)rad.量级。提高探测灵敏度的途径主要有:(1)稳定干涉臂,减小环境噪声的影 Interferometry is one of the most common and sensitive methods of measuring small optical phase shifts or path lengths. Commonly used direct broadband, direct current detection method due to the method itself and the technical conditions, can detect the minimum relative change in light intensity (△ I / I) _ (min) is about 10 ~ (-4) [1] The measured optical phase shift measurement sensitivity (ΔΦ) _ (min) is also on the order of 10 ~ (-4) rad. The main ways to improve the detection sensitivity are: (1) stabilize the interfering arm and reduce the impact of environmental noise