Nonlinear InGaAs-InGaAsP single-quantum-well all-optical switch - Theory and experiments

A detailed theory for the operation of a guided wave all-optical switch is presented and compared with experimental results. The switch exploits the two polarization-dependent bandedges of an InGaAs-InGaAsP single-quantum-well embedded in an InP waveguide and the dependence of refractive index on carrier density. This semiconductor all-optical nonlinear dichroic (SAND) device is potentially capable of operating at repetition rates up to ~50 GHz. The model which has been developed agrees well with the experiments and has been used to determine the optimum design and operating conditions for the device. In particular, it predicts that a gain of 23, with 54% modulation depth, should be achievable in realistic experimental conditions. e.