Quantum amplifier model for semiconductor lasers

Abstract

A quantum amplifier model for semiconductor lasers is developed in this dissertation. This model is capable of predicting the temporal variations of optical output power from semiconductor lasers on a picosecond time scale. For the first time, the polarization dynamics of lasing medium is taken into account by introducing the modified rate equations. It has also included the longitudinal nonuniformity of the laser parameters, together with the quantum noise of laser diode through the propagating photon packet approach. Semiconductor laser characteristics under various operating conditions are investigated systematically. It is found that the finite lasing medium response delay plays an important role in the laser operation, and the correction to the conventional rate equations approach can be substantial when quantum noise is included or when the laser diode is under high speed modulation. Quantitative results for the noise characteristics pertinent to some application systems are obtained using a Monte-Carlo method. Numerical simulation demonstrates that amplified quantum fluctuations can serve as a mechanism for inducing stochastic modelocking in semi; conductor lasers. The feasibility of using optimized active modelocking configuration to generate ultrashort optical pulses without large satelite pulses is also discussed.