Abstract

Future practical ultrafast (>100 Gbit/s) all-optical switching and information processing systems will need nonlinear optical devices which combine high speed of operation with moderate optical power requirements. Recently a large above-bandgap ultrafast optical nonlinearity has been observed in active semiconductor waveguides driven at the material transparency current^{1, 2}. The origin of the new nonlinearity is not yet clear. Dynamic carrier effects may contribute, as may a resonantly enhanced optical Stark effect, not normally observable in passive waveguides because of high interband absorption. In the case of active waveguides at transparency this optical loss is balanced by gain from the electrical pumping.

© 1993 Optical Society of America