Novel principle of the optical damage detection in nonlinear-optical crystals with RF oscillator

We introduce a novel principle of the laser-induced damage detection in nonlinear-optical crystals with radiofrequency (RF) oscillator. The method is based on the real-time measurements of the absorption coefficient using a Pierce oscillator. The proposed method was used to determine the laser-induced damage threshold (LIDT) of a lithium niobate crystal. The LIDT value was $500 \mathrm{~mJ} / \mathrm{cm}^{2}$, accounting for the self-focusing.