Quantum-confined Stark effect modulator based on multiple triple-quantum wells

A GaAs/AlGaAs triple-quantum-well structure is designed to have its lowest energy excitonic transition located significantly above the GaAs band gap, while maintaining large Stark shifts. We present photocurrent measurements of absorption features found in two different Al0.3Ga0.7As p-i-n diode structures: one contains multiple GaAs coupled-triple-quantum wells, and the other, multiple Al0.6Ga0.94As quantum wells. Both systems are designed to have their absorption edges at the same energy. The photocurrent spectra are compared, and preliminary 810 nm modulator results are presented based on the multiple triple-quantum-well approach.