Modelling of chirping laser diodes for microwave generation and transmission over dispersive fibres

For a sinusoidal modulation of the injection current we present optical and photocurrent spectra computed by a numerical large signal LD model, and compare the outcome to previous analytical and experimental results. We also treat successfully some cases of overmodulation, where temporarily the current falls below threshold. For lower modulation frequencies and below-threshold currents the optical power becomes significantly determined by spontaneous emission; in these cases our present deterministic model fails.