All-optical spin-dependent polarization switching in Bragg-spaced quantum well structures

All-optical polarization switching is demonstrated in a resonant photonic band-gap structure consisting of Bragg-spaced quantum wells (BSQWs). The switch takes advantage of the large spin-dependent optical nonlinearities and the ultrafast recovery present in BSQWs to produce large throughputs (greater than 40%), high contrast ratios (greater than 40 dB), and large optical bandwidths (similar to 0.6 THz), where both switching time and sample recovery time are control-pulse-width limited. (c) 2005 American Institute of Physics.