Abstract

We have investigated the spectral broadening of mid-infrared pulses due to nonlinear optical effects in semiconductor materials. The pulses of 100-fs duration at 4800 nm were focused onto semiconductor materials of Si, Ge, and GaAs. Spectral broadening by a factor of more than three was observed for GaAs when the input pulse energy was 3 micro-joule. The spectral bandwidth exceeded 750 cm⁻¹. The spatial distribution of the output spectrum was found to be almost homogeneous within the whole beam.

© 2009 Optical Society of America