Sub-picosecond timing fluctuation suppression in laser-based atmospheric transfer of microwave signal using electronic phase compensation

• Published in: Optics communications Vol. 401; pp. 18 - 22
• Main Authors: Chen, Shijun, Sun, Fuyu, Bai, Qingsong, Chen, Dawei, Chen, Qiang, Hou, Dong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2017
• Subjects: Frequency transfer; Instability measurement; Optical free-space communication; Phase compensation; Timing fluctuation suppression; Timing fluctuation suppression; Optical free-space communication; Frequency transfer; Instability measurement; Phase compensation
• DOI: 10.1016/j.optcom.2017.05.029
• ISSN: 0030-4018

We demonstrated a timing fluctuation suppression in outdoor laser-based atmospheric radio-frequency transfer over a 110 m one-way free-space link using an electronic phase compensation technique. Timing fluctuations and Allan Deviation are both measured to characterize the instability of transferred frequency incurred during the transfer process. With transferring a 1 GHz microwave signal over a timing fluctuation suppressed transmission link, the total root-mean-square (rms) timing fluctuation was measured to be 920 femtoseconds in 5000 s, with fractional frequency instability on the order of 1×10−12 at 1 s, and order of 2×10−16 at 1000 s. This atmospheric frequency transfer scheme with the timing fluctuation suppression technique can be used to fast build an atomic clock-based frequency free-space transmission link since its stability is superior to a commercial Cs and Rb clock. •Timing fluctuation suppression in atmospheric frequency transfer is proposed.•The mechanism relies on the compensation of the phase drift introduced by turbulence.•The round-trip reflected laser beam is used to measure one-way timing fluctuation.•Electronic phase shifter has a fast compensation speed and wide scale of adjustment.