InGaAlAs Multiple-Quantum-Well Optical Phase Modulators Based on Carrier Depletion

We fabricated carrier-depletion-type optical phase modulators which contain an InGaAlAs multiple-quantum well (MQW) in a p-n junction, and investigated their phase modulation characteristics at the wavelengths of 1.55-1.62 mum under reverse biased conditions. Fabricated devices showed large modulation efficiencies up to 89deg/mm/V and smaller wavelength-dependence than that of conventional MQW phase modulators. Carrier-depletion-type optical phase modulators are attractive for optical integrated devices such as optical matrix switches for future wavelength-division-multiplexing photonic networks.