SUBMILLIWATT OPTICAL BISTABILITY IN WAFER FUSED VERTICAL-CAVITY AT 1.55-MU-M WAVELENGTH

We report on low-power optical bistability in a vertical cavity struct ure at 1.55-mu m wavelength due to the bandgap resonant dispersive opt ical nonlinearity of InGaAsP, In this structure, a GaAs-AlAs Bragg ref lector grown on GaAs and the nonlinear medium grown on InP are bonded through waferfusion, leading to a high-quality vertical cavity after d eposition of a top dielectric mirror. This device shows interesting ch aracteristics for optical switching applications at fiber communicatio n wavelengths, such as a switching contrast higher than 8:1 in the ref lective mode and a bistability threshold power as low as 0.6 mW. True steady-state memory effect is observed with continuous-wave input, and the device switching time is in the ns range.