Abstract

Very large nonlinearities are observed in the vicinity of a bound exciton resonance in cadmium sulfide. Power levels of the order of 8 μW are sufficient for saturating the bound exciton resonance in a tight focusing geometry. In a more loosely focused geometry, power levels of the order of 250 μW are sufficient for saturating the bound exciton resonance and for observing optical bistability. Transverse effects are found to play a very important role. For all our measurements, no thermal contributions to the nonlinearity were observed. Since thermal effects are not playing a role and since the studied bound excitons decay radiatively in 500 psec, we infer subnanosecond switchoff and cycling times.

© 1983 Optical Society of America