The artificial metamaterial simultaneously possessing negative permittivity and permeability has many fantastic properties, and has attracted a lot of attention in the field of physics and electromagnetism. In this paper, we fabricated this kind metamaterial and performed refraction and beam shifting experiments using triangular-shaped and parallelogram-shaped sample respectively. The experimental results demonstrate that, the metamaterial we fabricated may have negative permittivity and permeability simultaneously in a specific small frequency band.
提出了两种基于光纤光栅以减小ROF(radio over fiber)系统中光纤色散引起的微波功率衰落的方法。第一种为采用窄带光纤光栅滤波实现微波信号的残余边带调制,另一种为采用啁啾光纤光栅实现光纤色散补偿。实验测量并比较了这两种方法与传统双边带调制时ROF系统传输性能的变化。结果表明,窄带光纤光栅和啁啾光栅均能有效减小ROF系统中的光纤色散效应。
