RF Transfer by Optical Comb Over 50-km Fiber Link With <inline-formula> <tex-math notation="LaTeX">$4.7\times 10^{-18}$</tex-math></inline-formula> Instability

Abstract

A radio-frequency (RF) dissemination system using an optical comb over a 50-km fiber link has been demonstrated in this paper. An optical filter is utilized to suppress the dispersion influence of the optical comb in the transfer fiber link. The compensation scheme, based on an electrical compensation structure with an optical-microwave phase detector, cancels the phase fluctuation introduced by the temperature variation and the mechanical vibration in the transfer fiber link. It has been demonstrated that the relative frequency instability of a 100-MHz transfer signal is $1.9\times 10^{-14}$ at 1 s and $4.7\times 10^{-18}$ at 16 400 s. It indicates that our frequency dissemination system can be used to transfer the most precise RF signal in the world to meet the demand of multiply applications.

Keywords

• RF
• dissemination
• optical comb
• Optical Branching Filter