Material properties of a new nonlinear borate crystal LiRbB/sub 4/O/sub 7/

Summary form only given. We report transmission and dispersive properties of LiRbB/sub 4/O/sub 7/ (LRB4) and present first results with second harmonic generation. Single crystals of LRB4 as large as 15 mm in diameter and 20 mm in length were grown by the Czochralski technique from a congruent melt in air. The measured transmission of LRB4 is similar to that of BBO. Although the band edge lies definitely below 190 nm residual absorption can be seen at short wavelengths which is attributed to the poor quality of the crystal in this initial stage of development. Experimentally we studied SHG phase-matching in LRB4 using /spl sime/120 fs pulses in the near-IR at the signal wavelength of an optical parametric amplifier pumped at 1 kHz by a 800 nm Ti:sapphire regenerative amplifier. We achieved SHG between 1.41 and 1.46 /spl mu/m for type-II interaction and at 1.42 /spl mu/m for type-I interaction in the X-Z plane although the Sellmeier expansions predicted no phase-matching.