Comparison of group velocity mismatch and dispersion in BaB2O4 and LiB3O5 crystals

Abstract

BaB2O4 (BBO) and LiB3O5 (LBO) are two of the new nonlinear optical crystals developed recently by Chen and his group in China, with a high nonlinear coefficient and usable in the UV wavelength. For sum frequency generation and measurement of ultrashort optical pulses, group velocity mismatch and dispersion are important parameters. The group velocity of ordinary and extraordinary light at the same wavelength is 400-600 fs/mm between 1300 and 300 nm for BBO and only 150-200 fs/mm for LBO. The group velocity mismatch in harmonic generation may be from 100 to 700 fs/mm for BBO for the fundamental wavelength from 1200 to 600 nm and only 50-450 fs/mm for LBO at the same region. As for the group velocity dispersion, values range from 10 to 380 fs2/mm in the wavelength from 1300 to 300 nm for BBO and from 1 to 180 fs2/mm for LBO at the same region.