近零平坦色散三包层光子晶体光纤的设计

为了使光子晶体光纤（PCF）在钛宝石飞秒激光器的工作波长0.80 m 和光通信窗口1.55 m 处获得宽的近零超平坦色散，使用了三包层六角空气孔环结构设计来代替普通的单包层结构。应用了改进的有效折射率法对该三包层PCF 进行了数值模拟。结果表明:三包层PCF 的色散随结构参数的微小变化而有较大的变化，因此通过对PCF 结构参数的合理调节，分别实现了在0.800.02 m 和1.550.15 m 波长范围内近零、平坦色散（色散范围0.5 ps/（kmnm），色散斜率范围0.02 ps/（kmnm2）的结构设计。这对于光通信系统及研究飞秒激光在PCF 中的传输特性，拓展飞秒激光的研究和应用都具有重要意义。

Design of triple-cladding photonic crystal fiber with near-zero flattened dispersion

In order to obtain the near-zero flattened dispersion at the wavelengths of 0.80 m and 1.55 m, at which the Ti: Sapphire femtosecond laser working wavelength and the optical communication window center, respectively, for the photon crystal fiber (PCF), we used the structural design of a triple-cladding PCF with the hexangular air-hole loop arrangement instead of the general mono-cladding one. Using the improved effective refraction index method on this triple-cladding PCF to perform the numerical simulation, we achieved satisfying results. The numerical simulation shows that the dispersion of this type of PCF changes apparently with small variations of the structural parameters, and therefore the structural designing, that leads to a near-zero(the dispersion range of 0.5 ps/(kmnm) and flattened (the dispersion slope range of 0.02 ps/(kmnm2) dispersion property at the wavelength ranges of 0.80 0.02 m and 1.550.15 m, respectively, is actualized through adjusting reasonably the PCF structural parameters. This result may play an important role on studying the optical communication system and femtosecond laser transmission characteristics in the PCFs to extend its applications.