Backside observation technique for SAW distribution under electrodes

A modified SAW distribution observation technique, which employs the polarization detection method, has been developed. A probe light was projected from the backside of the substrate to detect the SAW under the electrodes. The observed results proved that the origin of the leakage SAW is the penetration from the IDT (inter digital transducer) to the electrodes, and busbars transmit the wave as waveguides.