基于双光频梳及受激布里渊散射的微波频率测量

提出了一种基于双光频梳和受激布里渊散射的高精度微波频率测量方法,利用两个双平行马赫-曾德尔调制器将待测微波信号和扫描信号调制在两路光频梳上,并分别作为信号光和泵浦光输入色散位移光纤中。利用双光频梳和不断频移的扫描信号,系统可同时实现波分复用和时分复用。同时,在双光频梳和受激布里渊散射的作用下,系统可发生一系列的受激布里渊散射,通过测量各信道输出的光功率实现待测微波频率的测量。为进一步提升测量精度,利用测量得到的光功率值构建幅度比较函数,从而实现频率测量误差修正。通过实验仿真验证了所提方法的有效性,测量误差为±2.5 MHz。

Microwave frequency measurement based on dual optical frequency combs and stimulated Brillouin scattering

A novel high-accuracy microwave frequency measurement based on dual coherent optical frequency combs and stimulated Brillouin scattering was investigated. The unknown microwave signal and the sweep signal were modulated by two dual parallel Mach-Zehnder modulators as the signal optical and the pump signal which were lunched into the dispersion shift fiber. Using dual optical frequency combs and the sweep signal with shifted frequencies, the proposed measurement system could realize the wave-division and time-division multiplexing simultaneously. At the same time, the action of dual optical frequency combs and stimulated Brillouin scattering brought the system a series of stimulated Brillouin scattering. The frequency of the unknown signal was estimated by measuring the output optical power of the multiple channels. Furthermore, in order to improve the frequency measurement accuracy, the measured optical power values were employed to generate an amplitude comparison function which can be utilized for error correction. The effectiveness of the proposed scheme is verified via numerical simulations with a measurement error at ±2.5 MHz.