GaAs-AlGaAs Multi-Quantum Well Reflection Modulators Grown on GaAs and Silicon Substrates.

We present measurements of GaAs-AlGaAs multiple quantum well reflection modulators grown simultaneously on GaAs and silicon substrates. Comparable electroabsorption is observed, with contrast ratios of about 4:1 for both modulators at 20 volts. The absorption spectrum of the GaAs-on-Si quantum well shows a single exciton peak, which leads to certain improvements in modulator performance. From this study we concluded that GaAs MQW modulators may be grown on silicon integrated circuit chips for off-chip communication.