Research on subcarrier frequency signal generation based on FP-LD

In this paper, a convertion scheme of subcarrier frequency modulation signal is proposed based on Fabry-Perot cavity laser diode (FP-LD), including an FP-LD and an electro-optic phase modulator (PM). First of all, the sinusoidal phase modulation optical signal is obtained by the tunable lasers, electro-optic phase modulator and microwave source, then the phase modulated optical signal is injected into the FP-LD, and the low frequency phase modulated signal is convered into the subcarrier frequency modulation signal based on injection-locking in the FP-LD. In the experiment, the optical signals with 2 GHz, 3 GHz, 4 GHz and 5 GHz modulation frequencies are injected into the FP-LD, appropriate to be 22 GHz, 21 GHz, 24 GHz and 25 GHz subcarrier FM signal, respectively.