Suppression of phase noise deterioration induced by stimulated Brillouin scattering in high-power RoF links via phase modulation

High-power radio-over-fiber (RoF) links serve as a kernel technology for transmitting the clock signal from the central processing unit to the unit radar in distributed coherent aperture radar (DCAR) systems. Nevertheless, the phase noise deterioration induced by the stimulated Brillouin scattering (SBS) in the high-power and long-haul RoF link has to be firstly addressed. Herein, an approach to suppressing the SBS-induced phase noise deterioration in high-power long-haul RoF links is proposed and demonstrated via single-tone phase modulation. In the experiment, phase noise of the synchronous clock signal is reduced by about 10 dB at the offset frequency of 10 kHz in a high-power RoF link involving a spool of single-mode fiber with a length of 5 km. The proposed scheme can be applied in the DCAR systems to further improve detection performance and simplify structure of unit radars.