LiNa5Mo9O30: Crystal Growth, Linear, and Nonlinear Optical Properties

We report on the crystal growth, linear, and nonlinear optical properties of LiNa5Mo9O30. The refractive indices were measured, and a very large birefringence of 0.2545 at 450.2 nm was determined. In addition, calculated phase-matching curves indicate that LiNa5Mo9O30 can achieve noncritical type I and type II phase-matching (NCPM) for incident 1064 nm radiation. Maker fringe measurements, to determine individual nonlinear optical coefficients, were also performed on the crystals resulting in d31 = 1.4 pm/V, d32 = 4.3 pm/V, and d33 = 1.1 pm/V. The laser damage threshold (LDT) is around 1.2 GW/cm2 at 1064 nm using a 6 ns Nd:YAG laser operating at 5 Hz. The quality of the crystals was measured by high resolution X-ray diffraction rocking curve measurements that revealed a full width at half-maximum (fwhm) of 59″ from the (001) reflection. The absorption edge was determined to be 357 nm, with transmission up to 5.26 μm. Our results indicate that single crystal LiNa5Mo9O30 is an excellent polarizer as well as second-order nonlinear optical material.