Theoretical investigation of weak absorption and laser induced damage in YCOB crystals

Abstract

Weak absorption and laser-induced damage in crystals have been extensively studied, but the mechanism of these phenomena is still not well understood. Herein, we investigated the weak absorption and laser-induced damage in YCOB based on inelastic electron collisions using the one-dimensional quantum waveguide theory. The barrier strengths of precursor defects were calculated directly using the results of conventional weak absorption and laser damage measurements. The effect of YCOB crystal anisotropy on weak absorption is discussed, and the barrier strengths of precursor defects in three optical axes were calculated by the one-dimensional quantum waveguide theory, which were 0.0151 (X), 0.0143 (Y), and 0.0148 (Z), respectively. The damage thresholds of the crystals were 2.41 (X), 2.74 (Y), and 2.65 (Z) GW cm⁻². The contribution of mesoscopic clusters formed by the aggregation of precursor defects to the damage temperature was analyzed by a heat transfer model, and the barrier strength of mesoscopic defects causing crystal damage was calculated to be 0.18, and the corresponding energy absorption was 11% of the incident laser energy.