Abstract

Hot-carrier transport governed optical nonlinearity in dc-biased GaAs crystals has been investigated numerically and experimentally using picosecond four-wave mixing technique. An oscillatory behavior of light diffraction efficiency in subnanosecond time domain has been observed in the region of negative differential resistance. Numerical modeling of carrier and internal electric field spatial distribution and its dynamics allowed us to ascribe the oscillations to formation of high-field domains and their propagation through the spatially modulated structure. In this way, we demonstrated efficient and fast nonlocal refractive index modulation due to space-charge wave, which is driven externally by applied dc-voltage.

© 2003 Optical Society of America