Bragg cell and rotating grating frequency shifting in laser vibrometer: a metrological and operating comparison

摘要

An experimental comparison has been carried out between two laser Doppler vibrometers, different as for frequency shift generation between measuring and reference beam of the interferometer. In particular, two systems, based either on a Bragg cell or on a rotating diffraction grating for frequency shifting, have been compared, with reference to both metrological and operating behaviornBased on the analysis of experimental information, a quantitative evaluation has been carried out of the effect on either optical configuration of the most typical operative parameters to be taken into account in laser Doppler vibrometry, in order to define the best optical lay-out and configuration depending on the specific industrial application