Writing and reading indentation in frequency space of acoustic resonators

The writing of indentations in piezoelectric resonators was achieved by applying large amplitude oscillation, which introduced plastic deformations. The reading out of indentations was attained in the resonant oscillation space. They were described with the same notion as the hole burning phenomena. The detected indentation figures were well described the Fourier components of applied pulses. The measured change of damping time helped us to explain these phenomena and the memory echoes with dislocation model.