基于频率梳的太赫兹频率精密测量方法研究

High-Precision Measurement of Terahertz Frequency Based on Frequency Comb

利用光纤飞秒激光器与光纤耦合型太赫兹光电导天线,构建了一套全光纤太赫兹频率梳系统。基于锁相技术实现了对频率梳重复频率信号的高稳定度锁定,在取样时间为100 s时锁定精度达到3.3×10-13,并获得了信噪比优于50 d B的太赫兹拍频信号。基于频率梳测试方法实现了太赫兹频率的高精度测量,测量不确定度为5×10^(-11)。

A terahertz frequency comb system is built by using a commercial femtosecond fiber laser and a fiber coupled terahertz photoconductive antenna. The repetition rate frequency of the comb is highly stabilized based on phase-locked technique and the tracking stability is 3.3× 10-13 at sampling time of 100 s. The beat signal between terahertz test source and terahertz frequency comb is achieved with the signal to noise ratio being superior to 50 dB. The absolute frequency of terahertz test source is measured based on the frequency comb method with measuring uncertainty of 5× 10-11.