Highly-stable laser-based underwater radio-frequency transfer with electronic phase compensation

Abstract

We demonstrate a highly-stable laser-based underwater radio frequency transfer with electronic phase compensation technique. A 100 MHz radio-frequency signal has been transferred over a 5-m underwater link with this frequency transfer scheme. To evaluate the quality of the transferred frequency signal, timing jitter power spectral, timing fluctuations and instabilities were all measured. The transferred frequency signal over 5-m underwater link with electronic phase compensation achieved 2.1 ps of root-mean-square (RMS) timing fluctuations, meanwhile, the relative fractional frequency instability is 5 ×10−13 at 1 s and 7 ×10−16 at 1000 s for phase-compensated link. The transmission link achieved higher stability than Cs and H-master clocks, which gives this proposed transfer scheme the potential of disseminating these atomic clocks signal over the underwater transmission link.