Characterization of Ultrasonic Transducers Using the Schlieren-Technique

Acoustic pulse–waves in water generated by ultrasonic transducers with power levels in the medical diagnostic range are characterized by analyzing the optical diffraction patterns of short laser pulses due to pressure waves. The diffracted laser light is filtered in the Fourier–plane of an optical system and projected onto a CCD–camera. Using this technique it is possible to measure the ultrasound–field in a short time interval, which would otherwise last hours or days using the standard method of measuring the intensity in a large number of points in three dimensions with a hydrophone. Additionally the phase–information of the ultrasonic wave is acquired easily.