Photothermoelastic imaging at a flexural resonance frequency of a clamped plate sample

Abstract
Photothermal technique is studied for nondestructive imaging of irregularity in a platelike sample partially clamped circumferentially. By using a flexural resonance of the sample itself, the sensitivity for obtaining the image has been improved. The excitation efficiency for the resonant vibration at different positions of the heating laser beam is dependent on the resonance mode as well as the clamp condition.