Anisotropy of Nonlinear-Optical Property of RCOB (R= Gd, Y) Crystal

The nonlinear-optical coefficients of RCOB (R = Gd,Y) crystals are measured. The spatial distribution of d_eff effective nonlinear-optical coefficient) is determined subsequently. Our experiments show that the maximum d_eff occurs at the second quadrant. The second-harmonic-generation efficiency reaches 48% for a 6 mm-long, (113.2°, 47.4°)-cut GdCOB, and 41.5% for a 5mm-long, (113°, 36.5°)-cut YCOB, respectively. The intracavity frequency doubling of GdCOB is reported for the first time.