Nonlinear Optical Properties of Quantum Confined Semiconductor Microcrystallites

Results are given of recent studies on the nonlinear optical properties of quantum‐confined semiconductor (CdSSe) particles. The nonlinear mechanism is saturation of the first or 1s‐1s transition which behaves as a two‐level system. The intrinsic broadening of this transition by electron‐phonon coupling is very important and dominant at room temperature. The enhancement of the nonlinearity due to quantum confinement could however be observed, which may lead to important applications. Similarly, for hybrid devices, the static Kerr effect studied through the change in absorption spectrum induced by a defield shows a large nonlinearity which can be fully understood in terms of a Stark effect.