NONLINEAR-OPTICAL ABSORPTION OF GAAS QUANTUM WIRES

Nonlinear optical absorption at discrete frequencies (bleaching bands) has been observed for GaAs quantum wires in chrysotile asbestos nanot ubes with average diameter approximate to 6 nm. The induced decrease o f absorption has been explained by filling of the size-quantized energ y levels of quantum wires with nonequilibrium carriers (saturation eff ect). Strong (chi((3))= 10(-8) e.s.u.) and fast (relaxation time less than or equal to 50 ps) third order optical nonlinearity has been dete rmined.