抄録
The visualization of underwater pulse ultrasonic wave and the measurement of its sound pressure distribution are performed by real-time holographic interferometry with BSO single crystal. Sub-micro second Nd : YAG laser pulse generated by using acousto-optic modulator and wavelength 523nm is used as a light source. Optical path differences by the refractive index changes of water by propagating ultrasonic wave are recorded as holographic interference fringe patterns by CCD camera through the BSO single crystal. The phase shifts of the fringe pattern are obtained by Fourier transform fringe analysis. The sound pressure distributions measured by delay times are displayed by gray scale and the propagation of ultrasonic wave is visualized.
