Examination of vibration amplitude distribution of ultrasonic transducers using optical holography with a modulated reference beam

The theoretical base, experimental arrangement and results of the examination of the vibration amplitude distribution of ultrasonic transducers using an optical holography method with a reference beam whose frequency is shifted by the same amount as that of the vibrating object is presented. The thickness vibrations of transducers radiating into liquid in the frequency range 0.5 to 3 MHz have been examined.The minimum absolute value of displacement amplitude detected with this procedure is of the order 10^?9 m.