类矩形芯光子晶体光纤的色散与偏振特性

应用全矢量模型分析类矩形芯光子晶体光纤的色散和偏振特性，讨论了光纤结构参数对光纤特性的影响.研究表明：类矩形芯光子晶体光纤的模式双折射比普通椭圆保偏光纤至少高一个数量级.增大光纤的相对孔径，可获得更高的双折射.零走离点对应的波长也比普通椭圆保偏光纤长，随着孔距的增大，走离曲线将向长波长方向产生移位，零走离点发生红移，零走离点所对应的波长与孔距成正比.零走离点的出现，将有效地抑制一阶偏振模色散.通过调整光纤的结构参数，可以获得灵活的色散特性，在孔距Λ=2μm, 相对孔径d/Λ=03时，在波长155μm附近，获得近400nm的超平坦色散区.该光纤在偏振控制、色散控制和管理方面具有广泛的应用前景. 关键词： 导波光学 光子晶体光纤 类矩形芯 全矢量

Dispersion and polarization properties of near-rectangle core photonic crystal fibers

Dispersion and polarization properties of near_rectangle core photoric crystal fibers (PCFs) were analyzed with a full vector model. The numerical results show that the modal birefringence of near_rectangle core PCF is at least one order of magnitude higher than the conventional elliptical polarization_maintaining fibers (PMFs). In order to obtain higher birefringence, an efficient way is to increase the relative hole diameter. Zero walk_off point occurs at the longer wavelength than that of convention elliptical PMF. With increasing hole pitch, the walk_off curve and zero walk off point would shift towards the longer wavelength region. The corresponding wavelength of zero walk off point is in proportion to the size of the hole pitch. The occurrence of zero walk off point can efficiently restrain the first_order polarization mode dispersion. Through choosing the suitable structural parameter of near_rectangle core PCF, we can get the more flexible dispersion properties. The approximate 400nm ultra_flatten dispersion was gotten near the wavelength 155μm for a near rectangle core PCF with Λ=2μm and d/Λ=03 This fiber has a number of potential applications in polarization control, dispersion control and management.