Rate Equation Analysis of High Speed Q-Modulated Semiconductor Laser

Dynamic response of a Q-modulated semiconductor laser is simulated based on a rate equation model. Numerical results from both small-signal and large-signal analyses show that the Q-modulation has much higher bandwidth limit and smaller wavelength chirp than the direct modulation. It is shown that a high-extinction-ratio, low-chirp modulation of 40 GHz RZ signal can be achieved and the effects of various parameters on the Q-modulation are discussed. In addition to high-speed communications, the Q-modulated laser is particularly suitable for microwave carrier generation in radio-over-fiber systems.