Microscopic Simulation of Optical Gain in Multi-Quantum Well Lasers

Accurate simulation of optical gain in multi-quantum well lasers requires inclusion of band structure effects in the quantum wells, a proper treatment of broadening due to scattering and the inclusion of transport effects. Simulations agree well with experiments of InP based lasers. Although it is common to assume that multi-quantum well (MQW) semiconductor lasers operate under flat band conditions across the active region, detailed simulations show this assumption to be incorrect. Details of the carrier transport through the MQW region lead to important effects such as a non-uniform carrier population across the wells and changes in effective differential gain. Microscopic simulation of the optical gain must take these effects into account both to make meaningful contact to experiment as well to support realistic optimization of laser structures.