Ultrasonic Imaging System by Using Optical Pulse Compression

Abstract

The conventional ultrasonic imaging techniques including the holographic one give a high resolution in angle, but a relatively poor resolution in range, because the resolution in range is obtained only by use of selective focus or parallax useful only with a small focal ratio. This paper presents the principle and some experimental results of new ultrasonic imaging techniques that use a linear FM ultrasonic pulse and a pulse of light. This technique gives a high resolution both in angle and in range. It may be considered to be an application of pulse compression techniques used in chirp radar to the ultrasonic imaging. It has an image-forming capability as well as a range-discriminating capability.