The nonlinear optical coefficients of (YCOB) have been calculated for the first time to the authors’ knowledge by use of the revised Gaussian 92 program on the basis of the anionic group theory. The and coefficients of the crystal were determined by the Maker fringes method at and and were also evaluated by measurement of the Maker fringes. The coefficients determined by the Maker fringes are in agreement with the theoretical values. On the basis of the coefficients and the Sellmeier equations, the effective second-harmonic generation (SHG) coefficient of YCOB as a function of phase-matching angles θ and Φ was determined. It is interesting that the maximum effective SHG coefficient of YCOB is not in the principal plane but is located out of the plane in the positions and It is also worth noting that the largest of YCOB in the region of is larger than that in These calculated results have been proved by the effective SHG coefficient measurements of YCOB and conversion-efficiency measurements of frequency-doubling experiments on Nd:YCOB.
© 2000 Optical Society of America