带宽可调的斜边光纤光栅滤波器的设计与制作

基于遗传算法设计了斜边三角形光纤光栅(EFBG)的折射率调制函数；提出了光纤外径沿轴向变化、在拉应力下可获得可调谐的斜边三角形光纤光栅；计算分析了该器件多个物理参量对反射光谱的影响。在实验中，采用紫外激光扫描辐照方法，制备了短波边斜边带宽为0．7nm、反射率为96％的斜边三角形光纤光栅；采用程序控制氢氟酸腐蚀方法获得外径从原始62．5μm减小到45μm、在85mm长度内按设计要求变化的光纤光栅。对该光纤光栅施加从。到1．715N变化的拉力时，其反射光谱短波边的斜边带宽从0．7nm增加到2．3nm，实现了一种带宽大范围可调的斜边光纤光栅。

Analysis and Fabrication of Tunable Edge Fiber Bragg Grating Filters

The index modulation function of edge fiber Bragg grating (EFBG) is acquired using genetic algorithms synthesizing, and a method for fabricating tunable EFBG by changing the diameter of the fiber along its axis and applying tension to the fiber grating is proposed and testified. The influence of physical parameters of the device on the edge filter's reflection spectrum is analyzed. An EFBG with a bandwidth of 0.7 nm at shorter wavelength side and a peak reflectivity of 96% is fabricated by ultraviolet laser-scanning. The edge bandwidth of the fiber Bragg grating may be adjusted by tension and the edge bandwidth at shorter wavelength side increases from 0.7 nm to 2.3 nm as the tension increased from 0 to 1.715 N.