TAILORING THE HEAVY-HOLE AND LIGHT-HOLE QUANTUM-CONFINED STARK-EFFECTUSING MULTISTRAIN-STEPPED QUANTUM

We show theoretically how the quantum-confined Stark effect (QCSE) shi fts of the E1-HH1 and E1-LH1 energy transitions can be engineered to b e closely matched over the entire range of applied fields up to +/-100 kV/cm using structures containing more than one strained-layer compos ition within each well. In contrast, conventional quantum wells that c ontain a single uniform composition within each well can at best have the energy levels for the HH1 and LH1 states matched at only one field value, Furthermore, we show how the TE and TM absorption spectra are modified using multistrain-stepped structures leading to improved pola rization-insensitive QCSE modulators. (C) 1995 American Institute of P hysics.