Visualization of Three-Dimensional Ultrasonic Wave Fronts Using Holographic Interferometry

A new method to visualize wave fronts of a 3-D ultrasonic wave in a transparent medium is proposed. It employs holographic interferometry with phase-modulated reference beam. The wave field is illuminated by a sheet-like light and the light scattered in the medium is recorded in a hologram. The reconstructed image displays wave fronts of the ultrasound on the light sheet. The experiments are carried out for an ultrasonic wave with frequency 200 kHz and 1 MHz, and prove the validity of the method. This method is considered applicable for an ultrasonic wave frequency up to about 10 MHz