Determination of the nonlinear optical coefficients of YCa4O(BO3)(3) crystal

The nonlinear optical coefficients of YCa4O(BO3)(3) (COB) have been calcula ted for the first time to the authors' knowledge by use of the revised Gaus sian 92 program on the basis of the anionic group theory. The d(11), d(12), d(32),, and d(33) coefficients of the crystal were determined by the Maker fringes method at lambda = 1064 nm, and d(13), and d(31) were also evaluat ed 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 d(ij) coefficients and the Sellmeier equations, the effective second-h armonic generation (SHG) coefficient d(eff) of YCOB as a function of phase- matching angles theta and Phi was determined. It is interesting that the ma ximum effective SHG coefficient d(eff) of YCOB is not in the principal plan e but is located out of the X-Z plane in the positions theta = 65.9 degrees , Phi = 36.5 degrees and theta = 66.3 degrees, Phi = 143.5 degrees. It is a lso worth noting that the largest d(eff) of YCOB in the region of 0 degrees < theta < 90 degrees, 90 degrees < Phi < 180 degrees is larger than that i n 0 degrees < theta < 90 degrees, 0 degrees < Phi 90 degrees. These calcula ted results have been proved by the effective SHG coefficient measurements of YCOB and conversion-efficiency measurements of frequency-doubling experi ments on Nd:YCOB. (C) 2000 Optical Society of America [S0740-3224(00)00104- 1] OCIS code: 190.0190.