MODELING MULTIPLE-LONGITUDINAL-MODE DYNAMICS IN SEMICONDUCTOR-LASERS

We present a time-dependent coupled-wave equation analysis for simulat ing both single-and multilongitudinal-mode dynamics in semiconductor l asers, while incorporating frequency-dependent gain in a particularly simple way, In our first application, we analyze the response of Fabry -Perot semiconductor lasers to feedback levels ranging from -60 to -30 dB, This allows us to anchor, continuously, from single-mode phenomen a at weak feedback levels to multimode behavior at stronger feedback l evels, To our knowledge, this is the first simulation of multilongitud inal-mode dynamics that are induced in a laser at feedback levels exce eding -30 dB, Feedback-induced phenomena provide a significant test of both the single-mode and multimode capabilities of our coupled-wave m odel, In our second application, we analyze a modern, large-scale devi ce for which multiple longitudinal modes, as well as compound cavity m odes, are a significant possibility, Specifically, we consider facet-c oating requirements for a new class of monolithic master-oscillator po wer-amplifier (MOPA) devices.