啁啾长周期光纤光栅的滤波特性研究

Study on filtering characteristics of chirped long-period fiber grating

基于光纤光栅耦合模理论,采用传输矩阵法对啁啾长周期光纤光栅的啁啾系数和光栅参量(光栅长度、光栅周期和折变量)对其滤波特性的影响进行分析。当啁啾系数处于-0.000008～-0.0004 nm/cm范围内时,可用于宽带带阻滤波器。当啁啾系数处于-0.05～-1 nm/cm范围内时,可用于多通道窄带滤波器。为啁啾光纤光栅滤波器的优化设计提供理论依据。

The spectral characteristics of chirped long-period fiber grating are analyzed with the transfer matrix method based on the coupling theory. The influences of various chirp coefficients and structural features on the filtering char- acteristics are studied numerically. When the chirp coefficient varies between - 0.00008 nm/cm and 0. 004 nm/cm, it can be used for broadband rejection filters. While the chirp coefficient varies between - 0.05 nm/cm and - 1 nm/ cm,it can be used for narrow-band rejection filters. The results provide theoretical basis for optimal design of Chirped fiber grating filters.