Nonlinear properties of silica and air for picosecond ultraviolet pulses

Abstract

The nonlinear power limiting processes in silica and air are investigated for picosecond pulses at the KrF wavelength. The two-photon absorption coefficient and the nonlinear refractive index in silica are measured to be 0.06cm / GW and 1.7 x 10-13 e.s.u. respectively. A mechanism for the rapid spectral broadening in air based on Raman-enhanced four-wave mixing is proposed. Experimental evidence supporting this hypothesis is presented