Recent advances in laser-interferometric investigations of SAW devices

Abstract

Several improvements for our Michelson laser interferometer have been implemented. High frequency RF leakage has been suppressed to allow measurements at 1 GHz frequencies. Fast automatic computer-controlled focusing and high-precision XY-translation system provide two-dimensional scans with resolution better than one micrometer and with measuring speeds up to 7000 points/hour. At each probe point the interferometer can detect vibrations normal to the surface down to amplitudes on the order of an Angstrom. These advances, combined with the long working distance of the optical system, enable an efficient scanning of commercial SAW devices with speed and precision.