STRONG DYNAMIC OPTICAL NONLINEARITIES OF SEMICONDUCTOR QUANTUM WIRES

Nonlinear optical absorption at discrete frequencies has been observed in semiconductor quantum wires crystallized in a transparent dielectr ic matrix (inside chrysotile asbestos nanotubes). The induced changes of absorption in quantum wires have been explained by filling of the s ize-quantized energy bands with nonequilibrium carriers (dynamic Burst ein-Moss effect). renormalization of the one-dimensional energy bands at high density of the induced plasma; phase space filling, quantum-co nfined Stark effect and screening of excitons. The measured values of the exciton binding: energies are much greater than those of the corre sponding bulk semiconductors. The increase of the exciton binding ener gy may be attributed not only to the quantum confinement but also to t he ''dielectric confinement'' - to the increase of electron-hole attra ction because of the difference in dielectric constants of semiconduct or nanowires and the dielectric matrix.