Equivalent circuit model for active-layer photomixing: Parasitic-free modulation of semiconductor lasers

Direct modulation of a laser diode by active-layer photomixing is studied in terms of an equivalent circuit model. The model shows that this modulation technique achieves nearly perfect immunity to package, chip, and junction-related parasitic effects so that the measured modulation response reflects the intrinsic carrier-photon dynamics. The nonlinear gain effect is included in the model.