THE DESIGN AND APPLICATION OF III-V MULTIQUANTUM WELL OPTICAL MODULATORS

The application of an electric field across a quantum well structure induces a shift in the exciton dominated absorption edge. This effect is exploited in a number of optoelectronic devices including electro-absorption modulators, electron-refraction modulators, and optoelectronic logic devices. We will discuss how such modulators may be designed to operate at low voltages, with large changes in transmission or reflection and at high speeds. The choice of well widths, barrier widths, the use of coupled wells, and the enhancement due to Fabry Perot structures will all be considered. Results will be included for GaAs-GaAlAs, GaInAs-InP, and GaAs on silicon structures. Applications of these devices in optical interconnection of electronic circuits, and optoelectronic logic will be reviewed.