Techniques for SAW device investigation using a high-performance phase-sensitive laser probe

Five experimental techniques with associated data reduction and analysis methods for the use of a high-performance surface acoustic wave (SAW) laser probe are presented. These techniques take advantage of the laser probe´s high dynamic range phase-sensitive measurement capability and are useful for SAW substrate characterization, device physics study, and diagnostics at frequencies up to 1.8 GHz. The first technique is an improved-precision SAW slowness curve measurement method. This method uses multiple excitation frequencies and two transverse scans. The second technique involves detailed analysis methods to separately deduce the losses due to substrate attenuation and wave refraction and diffraction. A third technique applies signal processing techniques to the investigation of off-axis wave propagation effects. The fourth technique involves the examination of the time-domain response via laser probe, which serves in this case as an extremely wideband receiving transducer. The fifth technique involves the detection of bulk wave spurious that is reflected from the underside of the SAW substrate