Model for multimode picosecond dynamic laser chirp based on transmission line laser model

Laser chirp contributes significantly to the linewidth of near single-mode injection modulated semiconductor laser devices, and is a consequence of the carrier dependence of the active layer´s refractive index. A model is developed that can accurately predict the multimode chirped spectra of Fabry-Perot devices based on the transmission line laser model (TLLM), with the addition of a transmission line stub and attenuator to the end facets. This time-domain model is easily interfaced to both drive circuit and fibre impulse response models. A 1550 nm InGaAsP device model under picosecond modulation is tested against experimental and analytical results of other workers.