A new model for semiconductor laser high frequency performance based on Fermi energies

The small signal dynamic behavior of the semiconductor laser is considered in the context of a new model for the static characteristics. The analysis is performed in terms of quasi Fermi energies and the stimulated emission l ifetime and analytic expressions for the differential gain are obtained. Th e model is corroborated by detailed comparison with small signal dynamic me asurements of SCH lasers. The effects of gain compression are represented t hrough the temperature dependence of the refractive index, which shows up i n the photon lifetime, With this approach the gain compression factor can b e derived in closed form, The analysis is performed for the quantum well al one and then the effects of transport are added through the transfer functi on for conduction in the confining barrier regions. In a separate analysis the transfer function has been derived as a simple time constant RC. The K factor is derived to be consistent with previous work and the bandwidth of the peak response is derived in closed form, illustrating clearly the effec ts of transport. (C) 2001 Elsevier Science B.V. All rights reserved.