Yang Yonglan, Wang Xin, Xu Yuqiu, Liu Dunwei, Huo Juan, Zou Weiwen
Opt Lett. 2022 Jul 1;47(13):3243-3246. doi: 10.1364/OL.459524.
We demonstrate an ultrabroad instantaneous frequency measurement (IFM) based on stimulated Brillouin scattering (SBS) with a designed linear system response. The linear system response is found to be the key factor that broadens the system bandwidth. It is realized by designing the sweeping method of frequency and amplitude of the local pump signal. With the improvement of linearity, the measurement error is decreased and the bandwidth of the SBS-based IFM is consequently enlarged. A Costas frequency modulated signal with an instantaneous bandwidth of 10.5 GHz is successfully measured by the designed system response. Further optimization of pump signal's characteristics extends the system bandwidth to 14.5 GHz. The measurement error of a linear frequency modulated (LFM) signal ranging from 6 GHz to 20.5 GHz is less than 1% of the instantaneous bandwidth.
我们展示了一种基于受激布里渊散射（SBS）的超宽带瞬时频率测量（IFM），其具有设计好的线性系统响应。发现线性系统响应是拓宽系统带宽的关键因素。它通过设计本地泵浦信号的频率和幅度扫描方法来实现。随着线性度的提高，测量误差减小，基于SBS的IFM带宽因此得以扩大。通过设计的系统响应成功测量了具有10.5 GHz瞬时带宽的科斯塔斯调频信号。对泵浦信号特性的进一步优化将系统带宽扩展到14.5 GHz。频率范围为6 GHz至20.5 GHz的线性调频（LFM）信号的测量误差小于瞬时带宽的1%。
