CALIBRATION OF A FIBER TIP ULTRASONIC SENSOR UP TO 50 MHZ AND THE APPLICATION TO SHOCK-WAVE MEASUREMENT

An optical calibration technique is described, which allows the invest igation of the frequency response of ultrasonic detectors up to a freq uency of 50 MHz. This technique is applied to determine the transfer f unction of a metal-coated ultrasonic fiber tip sensor which is based o n an interferometric measurement of the displacement using a Michelson interferometer. The transfer function is used to correct shock wave d ata which are, by this means, measured with a calibrated system. (C) 1 998 Elsevier Science B.V.