Wideband SFCW and Local Oscillation Signal Generation Using Polarization-Based Dual-loop OEO

A polarization-based dual-loop optoelectronic oscillator (OEO) is proposed and demonstrated to simultaneously generate a high-quality local oscillation (LO) signal and wideband step frequency continuous wave (SFCW) signal. Since two sub-modulators perform the electro-optical modulation of different oscillation signals in an integrated dual-polarization modulator, two optical carriers with orthogonal polarization directions can be generated to transmit independently in the same single-mode fiber (SMF). Then, two independent oscillation loops are established in a simple structure, which helps to obtain a LO signal and a wideband SFCW signal simultaneously. In the experiment, a 10 GHz LO signal with the phase noise of -136.1 dBc/Hz@10 kHz and a 2 GHz SFCW signal with the signal-to-noise ratio (SNR) enhanced by 23.7 dB are obtained.