Conversion efficiency and absolute effective nonlinear optical coefficients of YCOB and GdCOB measured for different type I SHG phase matching configurations

Abstract

Different crystals of YCOB and GdCOB crystals cut and polished in ZX and XY principal planes and also out of principal plane were used to evaluate in the same conditions, the SHG type I conversion efficiency of Q-switched Nd:YAG laser (10 Hz, 6 ns). Furthermore absolute measurement of the effective nonlinear coefficients of YCOB and GdCOB were also performed on these different phase matching directions. The best directions are (θ=19.6, φ = 180) and (θ =67; φ =134) for GdCOB and (θ=31.7; φ = 180) and (θ =66; φ =35.3) for YCOB. More than 50% conversion efficiency was achieved for all these phase matching directions. The preliminary measurements of the absolute deff coefficients, for these different directions, were found to be 0.73 pm/V with an accuracy of 10%.