Sub-terahertz photonic frequency divider with a large division ratio based on phase locking

We present a photonic frequency divider with a large division ratio for microwave signals up to sub-terahertz. A high-operating frequency and a large frequency division ratio have both been achieved by phase-locking a Fabry-Perot frequency comb to the input signal that is to be divided. The input signals ranging from 50.10 GHz to 200.10 GHz are all divided to 2.5 GHz signals, which can be further divided into lower- frequency signals easily. The proposed divider is free of high-speed electrical devices, thanks to the intermediate-frequency detection and feedback control in the phase locking process. Moreover, the phase noise caused by the photonic frequency division is negligible at low offset frequencies, proving that the divider has superior long-term stability. This flexible, cost-efficient, and stable photonic frequency divider is an ideal candidate for frequency division at the remote end of a high-precision frequency transfer system.