A VERSATILE SPICE MODEL FOR QUANTUM-WELL LASERS

A SPICE equivalent-circuit model for the design and analysis of quantu m-well lasers is described, The model is based on the three-level rate equations which include, in their characterization of charge dynamics , the role of gateway states at the quantum well. The model is versati le in that it permits both small- and large-signal simulations to be p erformed, Emphasis here is placed on validating the model via a compar ison of simulated results with measured data of the small-signal modul ation response, obtained over a wide range of optical output powers fr om two lasers with different lengths of the separate-confinement heter ostructure (SCH). Using a set of tightly specified model parameters, a ll the important trends in the experimental data are reproduced, The c onsideration of gateway states is found to be important, with regard t o predicting the small-signal response, only for the laser with the lo nger SCH. This highlights the significance of the interplay between th e roles of transport through the SCH and capture/release via the gatew ay states at the quantum well.