Direct observation of longitudinal spatial hole burning in semiconductor optical amplifiers with injection

Measurements of spontaneous emission from InGaAsP semiconductor optical amp lifiers provide information on both the carrier density and temperature. By spatially resolving the light emitted along the active layer of the device , we find evidence of longitudinal spatial hole burning which results from amplified spontaneous emission in the structure and is modified by the inje cted optical signal. Under injection, we also observe pronounced asymmetry of the amplified spontaneous emission intensity from the two facets which w e relate to the carrier density profile. The experimental results are in go od agreement with numerical simulations. An analysis of the measured spectr a reveals an unexpected very high temperature (400 K) and its decrease by a t least 35 K in the middle of the device when light is injected. (C) 2001 A merican Institute of Physics.