Electroabsorption and Electrorefraction in an InAs Quantum-Dot Waveguide Modulator

Optical transmission measurements are reported in the 1.3-mum region in an InAs quantum-dot (QD) waveguide modulator using a supercontinuum generator. A quantum-confined Stark shift of 15 nm was demonstrated in a five-layer QD stack with a field of 270 KV/cm. The electrically induced change in absorption has been measured and the change in refractive index (up to 0.001) has been estimated via the Kramers-Kronig relations. This highlights the potential of such a device as an electroabsorption or electrooptic phase modulator at telecommunication wavelengths.