Coherent generation of 100 GHz acoustic phonons by dynamic screening of piezoelectric fields in AlGaN/GaN multilayers

Ultrashort pulse laser techniques have been used to observe and characterize the generation of coherent phonons by rapid screening of strain-induced piezoelectric polarization fields in AlGaN/GaN multilayers. The results are compared with those where coherent phonons are launched by optical techniques without the carrier injections process to show consistency with the anticipated longitudinal phonon dispersion in the nitride semiconductor samples.