Determination of Nonlinear Optical Coefficients of KBe 2 BO 3 F 2 Crystals

Considering that KBe2BO3F2 (KBBF) is an outstanding deep ultraviolet crystal which can generate the shortest wavelengths in second harmonic generation and sum-frequency generation, we report the determination of the nonlinear optical coefficients of the KBBF crystal. The d11 coefficient was determined to be 0.49 pm/V by the Maker fringes method at the wavelength 1064 nm, which is in agreement well with the theoretical value.