中文摘要：

为有效地阻挡长周期光纤光栅（LPFG）器件芯模,实现包层模提取技术,提出了利用磁流变液实现芯模阻隔（CMB）的新方法。从模式耦合理论出发,基于LPFG的单多模级联网络结构,分析了LP01模和HE13包层模与多模光纤（MMF）耦合效率随CMB器芯径的变化规律,并对CMB器尺寸进行了优化设计。根据理论分析结果,将磁流变液注入到半径为6.5μm的石英玻璃管,获得了带宽为4 nm、光隔离度为25 dB的带通滤波器。与传统的芯模自对准光刻法相比,本文方法大幅度地缩短了工艺周期、降低了加工成本、提高了产品的质量,满足了批量化生产的要求。

英文摘要：

In order to obstruct the core mode effictively and extract the cladding mode in a long-period fiber grating（LPFG）,a new core mode blocker（CMB） is proposed,which is fabricated by magnetic fluid.Based on the theory of mode coupling and a single mode fiber to multimode fiber network,the total coupling efficiency from HE13 cladding mode and LP01 core mode to the multimode fiber is investigated,and the core mode blocker radius is optimized.According to the results of theory analysis,a core mode blocker is acquired by pumping magnetic particle fluids into a hollow core fiber with 6.5 μm radius,and a band-pass filter with 4 nm bandwidth and 25 dB isolation is realized.Compared with the self-aligned technique,this method has the advantages of short cycle processing,low cost and good quality,so it can meet the requirements of mass production.