InGaAs-InP MQW Electro-Absorption Modulators

Abstract

InGaAs-InP multiple quantum well (MQW) structures are of particular interest for electro-absorption modulator applications because they offer the prospect of small, fast, monolithic spatial light modulator arrays compatible with the low loss optical fibre waveband at wavelength ~1.55μm. However, the QW absorption coefficients found in the InGaAs-InP system1 are significantly lower than those in the more widely studied GaAs-AlGaAs system2. This limits the changes in absorption coefficient provided by the quantum-confined Stark effect (QCSE) in InGaAs-InP, and hence the modulation attainable in single-pass structures3,4. A careful study of the QCSE in InGaAs—InP is therefore necessary to ensure that the full potential of this technologically important system is realised.