Resonant-level effects in the absorption spectra of shallow quantum wells

Abstract

The enhanced electroabsorption associated with the quantum-confined Stark effect has enabled new generations of optoelectronic modulators. However, the high-speed operation of such devices is compromised in deep quantum wells by the accumulation of photogenerated carriers in the quantum wells. While shallow quantum wells have been widely used to circumvent this difficulty, the influence of their pronounced resonant levels on the device behavior is not yet well understood. To illustrate the effect of shallow-well resonances, we consider first a 20-period multiple-quantumwell system formed from 1.46 /spl mu/m InGaAsP 95-A quantum wells separated by 1.1 /spl mu/m InGaAsP 80-A barriers in the intrinsic region of a p-i-n diode.