All-optical link for direct comparison of distant optical clocks

作者：Fujieda Miho^*; Kumagai Motohiro; Nagano Shigeo; Yamaguchi Atsushi; Hachisu Hidekazu; Ido Tetsuya

来源：Optics Express, 2011, 19(17): 16498-16507.

DOI：10.1364/OE.19.016498

We developed an all-optical link system for making remote comparisons of two distant ultra-stable optical clocks. An optical carrier transfer system based on a fiber interferometer was employed to compensate the phase noise accumulated during the propagation through a fiber link. Transfer stabilities of 2 x 10(-15) at 1 second and 4 x 10(-18) at 1000 seconds were achieved in a 90-km link. An active polarization control system was additionally introduced to maintain the transmitted light in an adequate polarization, and consequently, a stable and reliable comparison was accomplished. The instabilities of the all-optical link system, including those of the erbium doped fiber amplifiers (EDFAs) which are free from phase-noise compensation, were below 2 x 10(-15) at 1 second and 7 x 10(-17) at 1000 seconds. The system was available for the direct comparison of two distant Sr-87 lattice clocks via an urban fiber link of 60 km. This technique will be essential for the measuring the reproducibility of optical frequency standards.

• 出版日期2011-8-15