Large ultrafast optical nonlinearities in As-richGaAs

Abstract
The measurement of large ultrafast bandgap-resonant optical nonlinearities in As-rich samples of GaAs that have been grown at low temperatures is reported. Light-induced refractive index changes of magnitude greater than 0.1 and with picosecond response times have been observed. These materials appear to be promising candidates for the fabrication of compact, ultrafast all- optical devices.