Observation of separate electron and hole escape rates in unbiased strained InGaAsP multiple quantum well laser structures

We report on the first time-resolved photoconductivity measurements in strained InGaAsP multiple quantum well 1.3 μm laser structures. The photoconductive response is characterized by two exponential time constants, a fast time constant of less than 500 ps and a long time constant between 10 and 20 ns. We attribute these to the escape of electrons and holes from the wells, respectively.