Dependence of frequency response on different velocity sensitivities of laser Doppler vibrometer

Evaluation of responsiveness in the high frequency region of a laser Doppler vibrometers (LDV) is strongly demanded in industrial fields such as MEMS and biotechnology. Therefore, in order to obtain the responsiveness of the LDV in the frequency range that cannot be achieved by mechanical excitation, an electro optic modulator (EOM) that changes the refractive index instead of displacement was used. In this paper, we not only investigated the velocity sensitivity dependence and refractive index dependence of the LDV on the frequency response, but also verified the results of comparative calibration with the reference accelerometer. As a result, it was found that the EOM used in this experiment is very useful for calibrating the velocity sensitivity of the LDV above 10 kHz.