Supercontinuum generation in YAG and sapphire with picosecond laser pulses

Abstract

We report on experimental investigation of supercontinuum generation in YAG and sapphire crystals using 1.1 ps, 1055 nm laser pulses. Under loose focusing conditions a stable single filament is generated without the onset of optical damage within the input power range of 6 to 10 P_cr, as verified from the near and far field measurements, and which gives rise to stable and reproducible supercontinuum spanning from 460 nm to 1.4 μm in YAG, and from 410 nm to 1.3 μm in sapphire. Permanent material modification, which develops under multiple laser shot exposure, is identified as the main limiting factor, which deteriorates the intensity distribution of the filament and dramatically alters the supercontinuum spectra.