Multipoint stable radio frequency long distance transmission over fiber based on tree topology, with user fairness...

In this paper, we propose a multipoint stable radio frequency (RF) optical transmission system with tree structure. Based on the principle of phase conjugation, the phase jitter induced by environment variation can be compensated by frequency mixing. Different from other schemes, the RF signal is modulated on a optical comb at local and each tooth is grouped with a near subcarrier for a user. By using wavelength division multiplexer, these groups are separated and transmitted to the multiple points over fiber. Therefore, the degradation of compensation performance caused by the wavelength difference between the common main carrier and farther subcarrier can be avoided, and the accumulated power loss induced by the branch points will be significantly reduced. In addition, an acousto-optic modulator is used at the local station to depress the impact of Rayleigh scattering. Experimentally, we demonstrate 2.4 GHz RF signal transmission to the two users over 25 and 100 km fiber during 1 × 10⁴ seconds, and the phase jitter mean square errors are 2.50 × 10^-2 and 4.27 × 10^-2 rad, respectively.