A Widely and Continuously Tunable Frequency Doubling Optoelectronic Oscillator

We report a widely and continuously tunable frequency doubling optoelectronic oscillator (FD-OEO) based on a polarization modulator. The proposed approach is theoretically analyzed and experimentally verified. In a proof-of-concept experiment, the FD-OEO is continuously tuned from 8.8 to 37.6 GHz by adjusting the bandwidth of an optical bandpass filter inside the OEO loop. The phase noise performance of the generated microwave signals is also studied. The single sideband phase noise of the frequency doubled tone is below -103 dBc/Hz at an offset of 10 kHz.