A monolithically integrated dual-mode laser for photonic microwave generation and all-optical clock recovery

We demonstrate a monolithically integrated dual-mode laser (DML) with narrow-beat-linewidth and wide-beat-tunability. Using a monolithic DFB laser subjected to amplified feedback, photonic microwave generation of up to 45 GHz is obtained with higher than 15 GHz beat frequency tunability. Thanks to the high phase correlation of the two modes and the narrow mode linewidth, a RF linewidth of lower than 50 kHz is measured. Simulations are also carried out to illustrate the dual-mode beat characteristic. Furthermore, using the DML, an all-optical clock recovery for 40 Gbaud NRZ-QPSK signals is demonstrated. Timing jitter of lower than 363 fs (integrated within a frequency range from 100 Hz to 1 GHz) is obtained.