Direct Experimental Comparison of GaAs-AlGaAs Multi-Quantum Well Modulators Grown on GaAs and Silicon Substrates

Recently there has been a maturing of the technology of GaAs/AlGaAs multiple quantum well (MQW) p -i (MQW)-n modulators1-4 and related self electro-optic effect (SEED) devices 5-7 grown on GaAs substrates by molecular beam epitaxy (MBE). It has been demonstrated that these devices can operate at several GHz8, and that with the incorporation of an MBE-grown dielectric mirror beneath the modulator they may operate in reflection mode.4 These properties make MQW modulators attractive as a device for communicating off chip via optical signals. Since the majority of electronic devices are silicon, it is important to determine the quality of GaAs MQW modulators grown on Si substrates.