设计了一种三角形微结构光纤，利用全矢量有限元法对其模式特性进行了研究，发现此类光纤具有C3v 对称性，共支持4 类模式，基模为简并模式。对归一化空气孔直径d/Λ=0.986 不变，空气孔直径d 从10 μm 增大至16 μm时和d=14 μm 不变，d/Λ分别为0.946，0.966，0.986 时，光纤基模的色散特性和基模相位失配特性进行了研究。发现抽运光不变时，光纤结构参数的改变对斯托克斯波位置影响较大，但是反斯托克斯波长位置基本保持不变。利用中心波长为850 nm 的飞秒激光抽运自制的双包层微结构光纤的外包层，进行了四波混频的实验研究，分别在1859 nm 和551 nm 处得到了斯托克斯和反斯托克斯信号，其中反斯托克斯波位置与理论计算结果仅相差3 nm，强度与剩余抽运波强度比值达到73。

Microstructure fiber whose cladding is composed of three air-holes is designed. Its mode characteristics are investigated by full vector finite element method. Because of C3v symmetry, the fiber contains 4 distinct classes of mode and the fundamental mode is degenerate mode. The dispersion and phase mismatch in fundamental mode of the fiber is analyzed when d/Λ=0.986，d changes from 10 μm to 16 μm and d=14 μm，d/Λ changes from 0.946 to 0.986. It is found that with fixed pump, changes on fiber structure parameters have great influence on the position of Stokes signal while the position of anti-Stokes signal stays almost unchanged. Four-wave mixing and frequency conversion experiments are carried out in the outer cladding of a homemade double cladding microstructure fiber. Stokes and anti-Stokes signals at 1859 nm and 551 nm are observed respectively when pumping fs pulse with central wavelength at 850 nm. The experimental result agrees well with the theoretical prediction on the anti-Stokes signal wavelength with only 3 nm divergence. The ratio of anti-Stokes signal power to the residual pump power is as high as 73.