Stable RF transmission in dynamic phase correction with Rayleigh backscattering noise suppression

摘要

We propose a dynamic phase correction scheme for stable radio frequency (RF) transmission over fiber based on the phase-locked loop (PLL). Rayleigh backscattering noise is suppressed by separating the frequency of counter-propagating RF signals. We apply the optical carriers of the same central wavelength to the system. In this way, the effect of temperature induced group velocity dispersion (TIGVD) is effectively reduced and the symmetry of the round-trip transmission is improved. To eliminate fiber-induced phase variations during the round-trip transfer, the error signal drives the PLL structure to dynamically pre-compensate the phase of the outgoing 2.4 GHz signal. The stable frequency distribution over 80 km optical fiber with a relative frequency stability of 3.4E-17 at 10000 s is achieved, which is close to the noise floor.