Modeling of the frequency modulation response of semiconductor diode lasers

The modulation response of GaAlAs semiconductor diode lasers has been studied theoretically, with emphasis on wavelength modulation or frequency chirp. The laser model used is a nonlinear rate equation model that incorporates the wave equation for the lateral waveguide modes of the laser. Lateral diffusion of carriers in the active layer of the laser is taken into account via a one-dimensional diffusion equation. A small-signal analysis of the model has been performed to obtain the modulation response. The calculated amplitude and phase of the wavelength modulation relative to the power modulation are in good agreement with experiments. It is found that carrier diffusion has only a moderate influence on the modulation response.<>