National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK.
Opt Lett. 2010 Apr 1;35(7):1025-7. doi: 10.1364/OL.35.001025.
A high-stability microwave frequency reference is transferred over 50 km of spooled optical fiber by propagation of a 90-nm-wide optical frequency comb centered at 1.56 microm. Environmentally induced fiber phase noise is actively suppressed by returning the optical frequency comb via a separate fiber. The stability of the microwave frequency delivered is measured at the "user" end, eliminating the need for the assumption of correlation between the noise in the forward and return paths. The measured transfer stability is 4.6 x 10(-15)tau(-1), rendering this technique suitable for the transfer of state-of-the-art frequency references.
一段 90nm 宽、中心波长为 1.56 微米的光频梳通过绕制光纤传输 50km，实现了高稳定度微波频率基准的传递。通过单独的光纤返回光频梳，可以主动抑制环境引起的光纤相位噪声。在“用户”端测量传输稳定性，无需假设正向和反向路径噪声之间的相关性。测量的传输稳定性为 4.6 x 10(-15)tau(-1)，这使得该技术适用于最先进的频率基准传递。
