Abstract

Electroabsorption modulation requires the application of an external electric field to increase the absorption coefficient either by the Franz-Keldysh effect or the Quantum-Confined Stark effect. Reverse biased p-i(MQW)-n diodes have been used to generate these electric fields. Here we present an entirely new approach employing the Resonant Tunnelling (RT) effect in Double Barrier Quantum Wells (DBQW) embedded in an unipolar optical waveguide to generate and switch at high frequency an electric field across the waveguide core, allowing efficient high speed optical intensity modulation requiring a few hundred millivolt as RF drive signal with a bandwidth - voltage ratio of 33GHz/V, the highest reported for an electroabsorption modulator.

© 1998 IEEE