Deep UV nonlinear optical crystal:RbBe_2(BO_3)F_2

Abstract

Sizeable crystals of RbBe2(BO3)F2 (RBBF) were obtained by the flux method. The crystal structure was determined by x-ray data and the space group was proven to be R32, belonging to the uniaxial class. The linear and nonlinear optical parameters, including the cutoff wavelength, refractive indices, phase-matching angles, and effective nonlinear optical coefficients were determined for the first time to our knowledge, and then the Sellmeier equations were also constructed. By using an RBBF prism coupling device (PCD), tunable fourth-harmonic output from a Ti:sapphire laser and the sixth harmonic of an Nd-based laser were also obtained with relatively high power.