Field-induced broadening of optical absorption in InP-based quantum wells with strong and weak quantum confinement

Abstract

We have studied in detail the field-induced broadening of optical absorption in InP-based quantum well (QW) structures with both strong and weak quantum confinement. Electroabsorption process in the QW structures with the weak confinement is modeled taking both excitonic absorption and subband-to-subband absorption into account. It is theoretically shown that the spectral broadening associated with the applied electric fields is largely due to the quantum confinement of the barrier structures. In the InP-based QW structures absorption spectra, calculated assuming their broadening is due solely to carrier tunneling, successfully explain the measured photocurrent spectra.