论文部分内容阅读
应用等效折射率模型研究了光子晶体光纤 (PCF)的传播特性。介绍了光子晶体光纤的等效折射率模型。通过求解标量波动方程得到了光子晶体光纤包层基空间填充模的模式折射率 ,利用阶跃光纤的理论来研究光子晶体光纤的导模特性。应用此模型对不同结构光子晶体光纤包层区的等效折射率与波长的关系进行了讨论。包层区等效折射率与芯子的折射率差随波长的增加而增大 ,并由此阐述了光子晶体光纤的单模特性。数值分析得到光子晶体光纤的基模的模式折射率 ,并由此研究了光子晶体光纤的波导色散与结构参量的关系。分析表明 ,光子晶体光纤的波导色散随空气孔孔距的变化符合Maxwell方程的比例性质。空气孔的相对孔径对波导色散有重要的影响。这些分析表明光子晶体光纤具有可以灵活设计其色散特性的潜在应用前景。
The propagation characteristics of photonic crystal fiber (PCF) were studied by using the equivalent refractive index model. The equivalent refractive index model of photonic crystal fiber is introduced. By calculating the scalar wave equation, the mode refractive index of the photonic crystal fiber cladding was obtained and the guided-mode properties of the photonic crystal fiber were studied by the theory of step fiber. This model is used to discuss the relationship between the equivalent refractive index and the wavelength of the clad region of photonic crystal fiber with different structures. The difference between the refractive index of the cladding region and the refractive index of the core increases with the increase of the wavelength, and thus the single mode property of the photonic crystal fiber is expounded. The mode refractive index of the fundamental mode of the photonic crystal fiber is obtained through numerical analysis. The relationship between the waveguide dispersion and the structural parameters of the photonic crystal fiber is studied. The analysis shows that the waveguide dispersion of photonic crystal fiber changes with the air hole pitch in proportion to the Maxwell equation. The relative aperture of air holes has an important influence on waveguide dispersion. These analyzes show that photonic crystal fibers have the potential to be used flexibly to design their dispersion characteristics.