Influence of dopants on photo-induced damage in Gd xY 1−xCa 4O(BO 3) 3 crystal

Abstract

Selected metal oxides were explored as dopants for YCa 4O(BO 3) 3 (YCOB) during solid-state reactions to check their ability to withstand the laser irradiation during third-harmonic generation. The samples were subjected to powder gray-track (PGT) experiments to screen them before crystal growth. Most of the samples, including pure YCOB, exhibited characteristic brownish coloration, which is an indicator of gray-track formation, except for ZnO-doped YCOB. The inductively coupled plasma analyses on YCOB crystals grown with 3, 5 and 10 wt% of ZnO revealed that its presence in the melt facilitated the growth of YCOB with nearly stoichiometric composition. The PGT experiments showed that the laser-induced tolerance of YCOB grown with ZnO in the melt was about 15 times higher than that of pure YCOB. The bulk laser damage experiments exhibited that the threshold values were comparable for pure and doped YCOB crystals. The absorption coefficient of YCOB grown with ZnO in the melt was significantly lower than that of pure YCOB crystal in the visible region and electron paramagnetic resonance analysis on ZnO-(5 wt%) doped YCOB exhibited an additional peak before laser irradiation.