Investigation of Quartz Crystal Thickness Shear and Twist Modes Using a New Noninterferometric Laser Speckle Measurement Method

Abstract

The measurement of the mechanical vibration amplitudes of quartz crystals has been carried out by a variety of di ferent me hods. Interferometric methods'-4 firstly were used to investigate out-ofplane vibrations. Enhanced interferometric e ups also allow the measurem nt of in-plane vibrations . Holographic techniques present an instantaneous picture of the whole object, whereas the interferometric methods supply the vibration amplitude distribution point after point. 7 5 ,g