Modelling and experimental measurements of the switching behaviour of semiconductor optical amplifiers

A numerical model for the analysis of the switching response of semiconductor optical amplifiers is presented. Output phase and output power behaviour can be derived. This model considers the amplifier longitudinal nonuniformity related to the variation of the carrier and photon density along the device. Auger recombination and spontaneous and stimulated emissions are included in the model. The gain is considered via the parabolic band approximation. The carrier density distribution appears to play a key role in the amplifier behaviour since the computed results exhibit differences from uniform models. The dynamic evolution of the local carrier and photon density can be derived. This information will prove extremely useful in applications other than switching. The results for various rising and falling steps of electrical current are compared with experimental measurements. Good agreement is obtained for both the phase and the power response, supporting the validity of the model. The device chirping characteristics are analysed and discussed.