Preliminary Study of Laser Interferometry for Ultrasonic Detection and Medical Imaging

Laser ultrasonic effect has been studied since the invention of laser, however, not until recently some applications or studies were found in non-destructive evaluation of materials and biological tissues. This is due to the lack of effective optical methods for the detection of micro vibration of surface on the test object. Its remote and non-contact characteristics make it ideal for some special application where the test object is difficult to reach other than by optical method. A confocal Fabry-Perot interferometer (CFPI) is designed and realized on tissue phantom as the pick-up device of ultrasonic vibration and an excitng Nd-Yag pulsed laser.