Tunable frequency-doubling optoelectronic oscillator based on an optical-injected DFB laser

A tunable frequency-doubling optoelectronic oscillator (OEO) based on an optical-injected distributed feedback (DFB) laser is proposed and experimentally demonstrated. The selective gain properties of DFB laser is used to construct the tunable microwave photonic filter (MPF), as a result, no electrical bandpass filter (EBPF) is required in the OEO, which usually has a fixed center frequency, leading to a limited tuning range. The fundamental frequency of the OEO is tuned from 8.92 GHz to 17.88 GHz, and the doubled frequency at 17.84 GHz to 22.38 GHz are respectively illustrated. The phase noise of the generated 11.89 GHz microwave signal is measured to be -100.37 dBc/Hz at 10 kHz offset.