Tang Xiao-Li, Sun Bang-Shan, Shi Yi-Wei
School of Information Science and Engineering, Fudan University, Shanghai, China.
Opt Express. 2011 Dec 5;19(25):24967-79. doi: 10.1364/OE.19.024967.
Transmission characteristics at terahertz (THz) frequencies are numerically analyzed for elliptical dielectric-coated metallic hollow fiber (DMHF). Attenuation constants, group velocity, modal birefringence, and modal power fraction in the air core are presented. Optimization of the fiber geometry is investigated to reduce the attenuation and to increase the birefringence simultaneously. Modal birefringence of 3.3 × 10 -2 and attenuation of 2.4 dB/m are expected. It is found that a desirable ellipticity of the air core is around 3. And both the modal birefringence and the attenuation constant are inversely proportional to the cube of the core size. Multiple dielectric layers significantly reduce the attenuation and meanwhile have little influence on the modal birefringence.
对椭圆介质涂层金属空心光纤（DMHF）在太赫兹（THz）频率下的传输特性进行了数值分析。给出了衰减常数、群速度、模态双折射以及空气芯中的模态功率分数。研究了光纤几何结构的优化，以同时降低衰减并提高双折射。预计模态双折射为3.3×10⁻²，衰减为2.4 dB/m。发现空气芯的理想椭圆率约为3。并且模态双折射和衰减常数都与芯尺寸的立方成反比。多个介质层显著降低了衰减，同时对模态双折射影响很小。
