Abstract

All-optical switching with solitons in fibers has strong potential for cascadable operation at very high bit rates. In order to make small device (rather than a 10-m-length optical-fiber device), we need to fabricate devices with materials having a large optical nortlinearity. The excitonic nonlinearity in semiconductors is a good candidate. Distortion-free propagation of an intense femtosecond pulse is demonstrated in a semiconductor-waveguide structure.^1–2 In the exciton resonant region, however, we have strong group-velocity dispersion (GVD). This broadens the pulse duration and limits the maximum bit rate of the device. Thus it is important to find the conditions for distortion-free pulse propagation in semiconductors. In this paper, we present a new scheme of solitoniike propagation of exciton-polaritons just below the exciton resonance. In this scheme GVD of the exciton-polariton is compensated by the nonlinear dispersion caused by two-photon resonance (TPR) of biexcitons, as schematically shown in Fig. 1.

© 1994 Optical Society of America