Stabilized holographic setup for the real-time continuous measurement of surface vibrational mode patterns

摘要

We report the operation and performance of a time-averaged holographic interferometry setup for the measurement of vibrational mode patterns in a surface, using the He-Ne laser 632.8 nm wavelength line and a photorefractive Bi_(12)TiO_(20) crystal as the recording medium. The photorefractive crystal allows the real-time reversible recording and display of the hologram without any (chemical or thermal) development processing. The particular light polarization features of this sillenite family crystal allow the display of vibrational mode patterns and at the same time enable to actively stabilize the holographic setup. Good quality images are obtained even using low power laser beams requiring a long exposure time in comparatively perturbated environment.