提出一种新型混合晶格结构的高双折射PCF(光子晶体光纤),该光纤的截面由矩形空气孔和圆形空气孔混合排列而成.使用基于有限元法的Comsol软件研究了该光纤在空气孔填充温敏液体时光纤的双折射特性随温度的变化关系.研究结果表明,用乙醇液体填充纤芯区域的圆形空气孔,当空气孔间距Λ为1 μm,圆形空气孔直径D为0.96 μm,矩形空气孔长宽比a/b为4时,工作波长λ为1 550 nm的PCF的温度灵敏度达到10-5数量级.该光纤可用于高灵敏度PCF温度传感器.

A high birefringent hybrid lattice Photonic Crystal Fiber (PCF) with modified circular and rectangular air holes is proposed. When the air holes are filled with the thermo-sensitive fluid,the variations of its birefringence properties with temperature are investigated by using the finite-element method-based Comsol software. The research results show that when the circular air holes in the core area are filled with ethanol and the pitch of holes Λ=1 μm,the diameter of circular air holes D=0.96 μm and the aspect ratio of rectangular air holes a/b=4,the thermo sensibility of the PCF at excitation wavelength λ=1 550 nm reaches 10-5. The proposed fiber has broad application prospects in PCF temperature sensors with high sensitivity.