【摘要】 本文介绍了超声位移的激光外差干涉测量的原理、装置和结果，分析了减小探测限和抑制噪声的途径。本装置采用布喇格衍射盒作为激光的移频装置、锁相环作为调相信号的解调器．更多还原

【Abstract】 This paper describes the measuring principie,apparatus and results of ultrasonic displacement by laser heterodyne intrferometer.Decreasing the detective limit and restraining noise are analysed.We use a Bragg diffraction cell as the frequency shifter,PLL as the PM demodulator.更多还原