Examination of surface acoustic wave reflections by observing acoustoelectric current generation under pulse modulation

The authors investigate surface acoustic wave (SAW) reflections using the frequency dependence of the acoustoelectric current through a one-dimensional channel. By pulse modulating the transducer power with a short pulse width ( 0.2 μ s ) and matching the pulse repetition period to the delay time of a specific reflection path, the authors detect individual reflected SAW wave packets. Fourier transform results show that reflections from the sample edge behind the transducer and Bragg reflections from the second transducer have the strongest effects. The reflection power coefficients for these are estimated to be ≈ 0.29 and ≈ 0.99 , respectively.