压缩六角点阵椭圆孔光子晶体光纤的低色散高双折射效应

设计了一种新型结构低色散高双折射光子晶体光纤，该光纤纤芯缺失一根空气柱，包层沿光纤长度方向排布压缩六角点阵椭圆空气孔.采用全矢量平面波法，对其色散和双折射特性进行了数值模拟.研究发现，通过改变光纤结构参数，即改变六角点阵压缩比ξ、相对孔间隔f和空气孔椭圆率η，可以调节该光纤低色散高双折射工作波长.若调整光纤结构参数ξ=048， f=035, η=055， x方向孔间隔Λ_x=12　μm时，该光纤呈现低色散高双折射效应，在1360—167 关键词： 导波与光纤光学 全矢量平面波法 低色散高双折射 六角点阵压缩比

Low-dispersion high-birefringence effect of squeezed hexagonal lattice elliptical hole photonic crystal fiber

A new type of photonic crystal fiber for realizing the effect of low dispersion high birefringence is proposed. The fiber is composed of a solid silica core and a cladding with squeezed-hexagonal-lattice elliptical air-hole along the fiber length. Dispersion and birefringence are investigated simultaneously by using the full vectorial plane wave method. Simulations indicate that the wavelength for realizing low-dispersion high-birefringence can be controlled by artificially choosing the structure parameters of photonic crystal fiber, such as the hexagonal lattice squeezing ratio, the relative air hole spacing and the air hole ellipticity. The optimal and feasible parameters of the fiber with low-dispersion high-birefringence are given, with the result of the total dispersion being within ±5 ps ·nm^-1km^-1 over an ultra broad wavelength range from 1360 to 1670 nm and the corresponding high birefringence being about 1.5×10^-2 at 1550 nm.