Characterization of p-dopant interdiffusion in 1.3 micron InGaAsP/InP laser structures using modulation spectroscopy

We have investigated three In sub (1-x) Ga sub x As sub y P sub (1-y)/InP p-i-n multiple quantum well (MQW) laser structures with different p-doping profiles using contactless electroreflectance (CER) and piezoreflectance (PZR). From the observed Franz-Keldysh oscillations (FKOs) originating in the i-InGaAsP regions, we have evaluated the electric field and hence the amount of p-dopant interdiffusion, which is in agreement with secondary ion mass spectrometry measurements. The CER/PZR spectra from MQWs makes it possible to evaluate the parameters of these regions of the samples.