设计了一种中红外As2S3光子晶体光纤,利用多极法研究了这种光纤的双折射、色散和非线性特性.数值研究发现,该光纤在中红外波段λ=3.625μm处双折射B高达0.098;其x偏振方向的非线性系数γx达到了1.69m^-1·W^-1,y偏振方向的非线性系数γy达到了0.78m^-1·W^-1,该光纤在3—7μm的波长范围保持正常色散.将光子晶体光纤的传输波段扩展到中红外3—10μm,并且使得高非线性和高保偏特性在此光子晶体光纤中得到完美结合.研究结果对进一步研制中红外波段的新型光子器件具有重要意义.
A kind of midinfrared As2S3 chalcogenide glass photonic crystal fiber is proposed in this paper.The characteristics of this fiber are studied by multipole method,including high birefringence,chromatic dispersion,and high nonlinearity.Through numerical simulation,it is found that at midinfrared wavelength λ = 3.625 μm,the birefringence of this fiber reaches up to 0.098 and nonlinear parameters are 1.69 m-1·W-1 and 0.78 m^-1·W^-1 for x-polarized mode and y-polarized mode,respectively.In addition,the fiber keeps normal dispersion in a wavelength range from 3 to 7 μm.In conclusion,the band of transmitted wavelength extends into a midinfrared wavelength range of 3—10 μm,and high birefringence and high nonlinearity in this photonic crystal fiber are perfectly combined.The results are significant for the further development of new photonic devices.