基于标量近似理论利用有效折射率方法对低空气填充率的光子晶体光纤(PCF)的色散特性进行了数值模拟。发现通过调节光纤包层的空气穴节距或空气穴大小可以有效地调节光子晶体光纤的色散特性,可以实现光子晶体光纤零色散波长向短波方向(小于石英材料的零色散波长1.27 μm)移动,甚至在光通信波段出现两个零色散波长;可以设计在光通信波段接近于零色散的色散平坦光子晶体光纤,其色散系数D的绝对值在1.2～1.7 μm波长范围小于2.0 ps·km-1·nm-1,其色散斜率D′的绝对值小于0.02 ps·km-1·nm-2。

Basing on scalar approximation the dispersion property of photonic crystal fibers (PCF) with lower air filling fraction are investigated by an effective index approach in this paper. It is found that the dispersion property of PCF can be modulated effectively by changing the pitch and the air hole size in PCF cladding. PCF can be designed not only with less than 1.27 μm zero-dispersion wavelength but also with two zero-dispersion wavelengths at the wavelength of optical communication. PCF with closing to zero and flattened chromatic dispersion in wavelength division multiplexing waveband of optical communication can also be obtained. The designed PCF has absolute value less than 2.0 ps·km-1·nm-1 in dispersion coefficient D and absolute value less than 0.02 ps·km-1·nm-2 in dispersion slope D′ at the wavelengths from 1.2 μm to 1.7 μm.