Brillouin spectroscopy applied to the characterization of SAW propagation losses in langasite

High performance Brillouin microscopy has been used in order to directly measure the propagation losses of surface acoustic wave in Langasite substrate. The interdigital transducers (IDTs) were designed to generate several harmonics leading to induce acoustic waves with different wavelengths. The induced phonons were detected and characterized at different frequencies and at different distance from IDTs leading to precisely determine the propagation losses for all the excited frequencies 681, 1267 and 1463 MHz.