利用全矢量有限元法设计了一种非对称三角晶格SPSM-TPCF(单模单偏振太赫兹光子晶体光纤),该光纤具有高双折射、宽带宽、低平坦色散和SPSM 传输等特性.分析结果得出,在330μm 处,双折射高达0.0365,拍长为9.04mm;x 和y 偏振模的限制损耗分别为48.01和0.00813dB/m;y 偏振模的有效模场面积为7557μm^2,数值孔径为0.56.在波长326.5-359μm 范围内实现SPSM 传输,且y 偏振模损耗始终低于0.1dB/m;该光纤呈现低平坦色散特性,色散值仅为(-2.14±0.45)ps/(nm·km).
An asymmetric triangular lattice-based Single Polarization Single Mode Terahertz Photonic Crystal Fiber (SPSM-TPCF)is designed by using the full-vector Finite Element Method (FEM),which is characteristic of high birefringence,wide bandwidth and low-flat dispersion.The analytical results show that its birefringence is as high as 0.036 5 at the wavelength of 330 μm,the beat length is 9.04 mm and the confinement losses of the x- and y- polarization modes are 48.01 dB/m and 0.008 13 dB/m respectively.In addition,the effective mode field area of the y-polarization is 7 557 μm2 ,the numerical aper-ture is 0.56,the SPSM transmission is realized in the wavelength range of 326.5 ~359 μm,in which the confinement loss of the y- polarization mode is always below 0.1 dB/m and this fiber is dispersion-flattened,with the dispersion value as low as (-2.14±0.45)ps/(nm·km).