Refined Sellmeier and thermo-optic dispersion formulas for Li2B4O7

We report the high-accuracy Sellmeier and thermo-optic dispersion formulas for Li2B4O7, which provide an excellent reproduction of the temperature-dependent phase-matching conditions for second-harmonic generation (SHG) and sum-frequency generation (SFG) in the 0.2093–1.5352 µm range. In addition, Li2B4O7 was found to be nearly 90° phase-matchable for fifth-harmonic generation (5HG) of an Yb-doped fiber laser at 1.031 µm.