A study on the measurement of vibration using Laser Doppler Interferometer

레이저 도플러 간섭계를 이용한 진동 측정에 관한연구

Laser Doppler Vibrometer using heterodyne method with a 632.8 nm He-Ne laser, has been developed for the measurement of small displacement and velocity. The measurement uses heterodyne method can be made insensitive to undesired vibration effect acting the system and can yield the sign of Doppler shift at the expense of increased complexity. A Bragg cell gives a frequency shift of 40MHz for heterodyne method. Frequency Modulated output is detected by spectrum analyzer.