Frequency division optoelectronic oscillator for high division factor

An optoelectronic oscillator (OEO) is a traditional microwave photonic loop for low-phase-noise signal generation and processing. OEOs also find applications in many other fields, such as frequency division. Frequency division plays a crucial role in applications such as telecommunication systems, modern radar systems, and optical frequency tracking. Nowadays, frequency division systems with a large division factor and low additive phase noise remain an active research area. An effective scheme for frequency division with a large division factor and low additive phase noise has been theoretically and experimentally demonstrated by employing a frequency division optoelectronic oscillator (FD-OEO). In the proposed FD-OEO, an oscillation signal with a frequency of near 1/n of the reference is first generated in the cavity. The oscillation signal is then multiplied by an MZM in the nonlinear section. Then the multiplied signal is mixed with the reference and the down-converted signal is fed back to the oscillation cavity. The cavity is locked with the feedback, and finally a divided-by-n frequency division is achieved. Our proposed FD-OEO achieves a 9 GHz reference input and a 1 GHz output, corresponding to a division factor of 9. The additive phase noise of the proposed FD-OEO is −155 dBc/Hz at 10 kHz offset with a cavity delay of approximately 100 ns.