CALIBRATION OF AN INTERFEROMETRIC FIBER TIP SENSOR FOR ULTRASOUND DETECTION

The experimental determination of the transfer function of a metal-coa ted ultrasonic fiber tip sensor for frequencies up to 40 MHz is presen ted. The transfer function is defined as transmission factor of acoust ical displacement. The fiber-optic measurement is based on an interfer ometric determination of the displacement using a Michelson interferom eter. To measure the incident field, time-delay spectroscopy (TDS) wit h a calibrated hydrophone and an interferometric foil technique were u sed as reference methods. The frequency dependence of the transfer fun ction obtained is discussed and compared with theoretical models. (C) 1997 Elsevier Science B.V.