Phase-preserving imaging of high frequency surface acoustic wave fields

Abstract Measurements of the acoustic wave field of high frequency surface acoustic wave (SAW) devices have to be performed in order to develop and improve the computer modelling of SAW propagation. We introduce a method which detects the angle deflection of a laser beam due to the mechanical undulation of the substrate surface and in addition has a high temporal resolution capability by the use of a picosecond laser source. The shortness of the optical pulses (3 ps) in the time domain transforms to a large bandwidth (greater than 10 GHz) of the measurement limited only by the jitter of the driving electronics.