For the numerical analysis of the loss properties of Photonic Crystal Fibers（PCF）

this paper studies the effects of such structural parameters as air hole diameter

space between air holes and the number of air hole rings in the cladding on the PCF loss properties at 1.31 and 1.55 μm by the multipole method.The results show that the loss can be reduced by choosing structures with high air-fill scale and increasing the air hole rings in the cladding and that it can be dramatically decreased by increasing the outermost air hole diameter while keeping the dispersion property constant.This conclusion provides a theoretical basis for the design of PCF with low loss property.