CsLiB 6 O 10 crystal: forth and fifth-harmonic generation in Nd:YAP laser

Abstract

An area of CsLiB6O10 (CLBO) phase equilibrium in the (Cs2O-Li2O) -- B2O3 -- MoO3 system was determined with spontaneous crystallization method. Crystals of 75 X 60 X 40 mm3 size have been growth in [100] direction with Kiropulos method. The forth-harmonic generation (270 nm) was achieved through the doubling of second-harmonic frequency in a multi-mode Nd:YAP laser in the type 1 collinear phase-matched geometry. The second-harmonic radiation in the technological laser of 3 mrad divergence was focused onto the input face of the crystal by a long-focus quartz lens. The input power density of the second harmonic was 300 MW/cm2. Using a 11.5 mm crystal, we showed that the highest efficiency of the forth-harmonic generation is 30%. The fifth harmonic (216 nm) in CLBO crystal was generated by composing the main laser beam and the forth-harmonic beam under the type 1 collinear phase-matching. Both beams were converged with dichroic and turning mirrors and then focused by a long-focus quartz lens. Our experiments showed that the fifth-harmonic generation in a multi-mode technological laser of 3 mrad divergence is possible in a 10 mm CLBO crystal of 23% optical conversion efficiency. The input power density of the forth harmonic was 100 MW/cm2. The use of longer CLBO crystal is less effective due to the nonlinear UV absorption and the walk off between the pump beam (1079 nm) and the harmonic beam.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.