Geng Youfu, Li Xuejin, Tan Xiaoling, Deng Yuanlong, Yu Yongqin
College of Physics Science and Technology, Shenzhen Key Laboratory of Sensor Technology, Shenzhen University, Shenzhen 518060, China.
Opt Express. 2013 Jul 15;21(14):17352-8. doi: 10.1364/OE.21.017352.
In this paper, an in-line comb filter with flat-top spectral response is proposed and constructed based on a cascaded all-solid photonic bandgap fiber modal interferometer. It consists of two short pieces of all-solid photonic bandgap fiber and two standard single-mode fibers as lead fibers with core-offset splices between them. The theoretical and experimental results demonstrated that by employing a cut and resplice process on the central position of all-solid photonic bandgap fiber, the interference spectra are well tailored and flat-top spectral profiles could be realized by the controllable offset amount of the resplice. The channel position also could be tuned by applying longitudinal torsion with up to 4 nm tuning range. Such a flat-top fiber comb filter is easy-to-fabricate and with a designable passband width and flat-top profile.
本文提出并构建了一种基于级联全固态光子带隙光纤模态干涉仪的具有平顶光谱响应的在线梳状滤波器。它由两段短的全固态光子带隙光纤和两根标准单模光纤作为引线光纤组成，它们之间通过纤芯偏移熔接相连。理论和实验结果表明，通过在全固态光子带隙光纤的中心位置进行切割和重新熔接操作，干涉光谱能够得到很好的调整，并且通过重新熔接的可控偏移量可以实现平顶光谱轮廓。通过施加纵向扭转，通道位置也可以进行调谐，调谐范围可达4nm。这种平顶光纤梳状滤波器易于制造，并且具有可设计的通带宽度和平顶轮廓。
