Evanescent wave coupling for piezoelectric excitation of coherent THz acoustic phonons

Piezoelectricity

“…Keilmann et at. developed a technique for generating coherent acoustic phonons at THz frequencies using quartz and a high power far-infrared laser (190). A germanium prism was employed for evanescent wave coupling to ensure that the driving laser field was present in a thin surface region of the piezoelectric crystal, but was negligible farther inside.…”