为进一步提高激光多普勒测振仪(LDV)的测量分辨率，实现物体表面微小振动的测量，设计了一种以双频环形激光器作为光源的LDV，介绍了该系统的光源及光路结构，推导了测振原理，并通过实验验证了该系统的可行性和准确性。在该系统中，利用四频差动激光陀螺频差稳定和谱线窄的优点，将四频差动激光陀螺改进为双频环形激光器，产生两束具有一定夹角和固定频差的线偏振光，结合光栅技术可实现对物体表面横向微小振动的测量。与其他LDV 相比，该系统光路简单且分辨率较高，在实验室环境下振幅分辨率最大噪声不超过0.012 μm·Hz^{1/ 2} 。

In order to improve the resolution of the laser Doppler vibrometer (LDV) and measure surface microvibration, an LDV equipped with a dual-frequency ring laser is proposed. The source and optical path structure of the system are introduced, and the measurement principle is derived. The dual-frequency ring laser, modified by a multioscillator ring laser gyroscope with stable frequency difference and narrow linewidth, can emit two beams in two directions and the two beams show a certain angle and have a fixed frequency difference. Combined with the grating technology, the surface transverse microvibration measurement can be realized. Compared with other LDV, the system has simple optical path and high resolution, and the maximum noise of amplitude resolution is lower than 0.012 μm·Hz^{1/ 2} in the laboratory experiment.