Simulation of Active Regions of Semiconductor Lasers and Optical Amplifiers based on Quantum Wells

Simulation of band structure, potential profile and carrier transport in QWs are highlighted. Anisotropy of the valence band on the density of states and gain spectra of QWs is addressed. It has been shown that axial approximation leads to underestimated gain. Errors can amount to 18.8%. Results of selfconsistent computation of energy band diagram for compositionally asymmetric multiple quantum-well structure are presented. Flat-band approximation of quantum-well potential profile is examined. Quantum capture and tunneling in SQWs and MQWs are considered. It is shown that tunneling do play significant role in high-speed properties of (A)MQW SOA and prediction of SOA gain spectrum. Is is shown that quantum capture area is a function of temperature and injection level, and consequently is governed by composition and structure of a QW-device and its operating point.