Bandwidth Enhancement by Master Modulation of Optical Injection-Locked Lasers

In normal injection-locked semiconductor lasers, the modulation signals are applied to the slave laser. In this paper, we show that modulating the master light before injection exhibits distinctive modulation dynamics and frequency response. We first present a detailed theoretical model and simulation results. Experimentally, we have successfully demonstrated both master amplitude and master phase modulation. The resulting 3-dB bandwidths have been enhanced by up to three times, exceeding 50 GHz. The resonance frequency of the combined lasers is greater than 100 GHz.