FABRICATION OF PHOTONIC INTEGRATED-CIRCUITS USING QUANTUM-WELL INTERMIXING

Intermixing the wells and barriers of quantum well structures generall y results in an increase in the band gap and is accompanied by changes in the refractive index. A range of techniques, based on impurity dif fusion, dielectric capping and laser annealing, have been developed to enhance the quantum well intermixing (QWI) rate in selected areas of a wafer. Such processes offer the prospect of a powerful and relativel y simple fabrication route for integrating optoelectronic devices and for forming photonic integrated circuits (PICs). Recent progress in QW I techniques is reviewed, concentrating on processes which are compati ble with PIC applications, and illustrated with device demonstrators.