A surface-normal coupled-quantum-well modulator at 1.55 μm

We demonstrate a surface-normal coupled-quantum-well InGaAs-InAlAs electroabsorption modulator that provides optical modulation with a contrast ratio in excess of 1.5 at only 6 V. The device operates at 1.55 μm and is based on a novel strain-balanced layer structure. The operating voltage is about two times lower than that of a conventional square quantum-well modulator that achieves a comparable contrast ratio.