title: The highly sensitive optical measurement of absolute SAW amplitudes for power flow analysis.
abstract: The established optical method for the measurement of surface acoustic wave (SAW) amplitudes (simple probing) has been modified to result in the effective separation of scattered light from the SAW-diffracted light by means of two single mode optical fibers. In this way, the photodetector noise is drastically reduced, and absolute SAW amplitudes of 10(-12) m can be detected easily. Using an additional precise measurement of the nondiffracted light by means of fiber shifting, the SAW amplitudes can be calibrated with an error of less than 3%. This method can be applied to deliver an accurate power flow analysis in SAW devices. As an example, for a YZ-LiNbO3 transducer, the measured and calculated SAW power densities were found to agree within better than 6%.
authors.affiliation: Institut fur Festkor per und Werkstofforschung, D-01069 Dresden, Germany. k.franke@ifw-dresden.de
authors.forename: Kurt
authors.initials: K
authors.lastname: Franke
authors.forename: Martin
authors.initials: M
authors.lastname: Ross-Messemer
authors.forename: Alexander
authors.initials: A
authors.lastname: Menck
authors.forename: Frank Stefan
authors.initials: FS
authors.lastname: Hoeller
authors.forename: Hagen
authors.initials: H
authors.lastname: Schmidt
authors.forename: Manfred
authors.initials: M
authors.lastname: Weihnacht