采用全矢量有限元法设计光子晶体光纤

Design of Photonic Crystal Fiber Using Full Vector Finite Element Method

阐述了基于光子晶体光纤(PCF)的光纤参量放大器(FOPA)的工作原理,对FOPA所需的PCF特性进行了讨论和设计。采用带混合节点/棱边元三角形单元的全矢量有限元法(FEM),计算了PCF中非线性系数、色散斜率和色散零点与空气孔半径、孔间距和空气填充比等结构参数间的关系。计算结果表明在确保PCF光纤高非线性的前提下,通过灵活设计PCF的结构参数就可以实现色散控制,得到PCF的超宽波长范围内可调的零色散波长、近零超平坦色散和极低的色散斜率,从而为FDPA获得高增益、宽带宽等性能创造必要前提。

The operating principle is analysed for optical parametric amplifiers based on photonic crystal fiber（PCF）. The properties of photonic crystal fiber needed for optical parametric amplifier are discussed and designed. Using full vector finite element method（FEM） with hybrid nodal/edge elements with triangular shape, the relationship between the properties of PCF such as nonlinearhy,dispersion slope and zero-dispersion wavelength and of PCF structure parameters of PCF such as the diameter of the air holes,the hole pitch and the air filling factor is investigated. The simulation results show that while keeping high nonlinearity,zero-dispersion wavelength that is adjustable over large wavelength range,near-zero ultra-flattened dispersion and dispersion slope can be achieved by flexibly designing PCF＇ structure parameters, in such a way high gain and wide bandwidth of FOPA can be achieved.