基于非对称形变的全光纤宽阻滞滤波器的制作

本文提出的基于长周期光纤光栅（LPFG）的全光纤宽阻带滤波器的制做方法，基本原理是在光纤纤芯中引入周期性的非对称形变，从而使光纤纤芯的折射率发生周期性变化；提出了两种实现光纤纤芯非对称形变的方法，进而制做出阻带中心波长分别为1310nm和1550nm的全光纤宽阻带滤波器插入损耗分别小于0.8dB和1.4dB，后向反射损耗小于-70dB。这样的器件可用于提高WDM系统的隔离度。

Fabrication of All-fiber Broadband-rejection Filters Based on Asymmetric Fiber Deformation

A new method of fabricating all fiber broadband rejection filter based on long period fiber grating (LPFG) is proposed.The key principle of the method is to make periodic asymmetrical deformation in the core of fiber without microbends so that to induce periodic refractive index changes.Two ways to realize the asymmetrical fiber deformation are introduced and two kinds of filters whose rejection peak wavelength at 1 550 nm and 1 310 nm are obtained.The insertion loss is less then 0.8 dB and 1.4 dB respectively.The backward reflection loss is less than -70 dB.Such devices can be used as isolation filters in WDM systems.