提出了一种基于狄拉克半金属超材料的双开口环结构的宽带偏振器,研究了狄拉克半金属费米能级以及中间介质厚度对偏振转换性能的影响。结果表明:当中间介质厚度为22 μm,费米能级为70 meV时,在1.44 THz和1.95 THz两个谐振频率处,偏振转换效率为100%;当中间介质厚度为22 μm时,随着狄拉克半金属费米能级从64 meV增加到70 meV,高低两个谐振峰均产生蓝移;当狄拉克半金属费米能级为70 meV时,随着基底介质厚度从19 μm增加到22 μm,低频处的谐振峰未移动,高频率点处的谐振峰红移。

In this study, we propose a broadband polarizer based on the “double-split ring” structure of a Dirac semimetal metamaterial. Further, we investigate the influences of the Dirac semimetal Fermi level and the intermediate dielectric thickness on the polarization conversion performance. The results show that the polarization conversion efficiency is 100% at two resonance frequencies of 1.44 THz and 1.95 THz for an intermediate dielectric thickness of 22 μm and a Fermi level of 70 meV. In addition, For a 22 μm thick intermediate dielectric, the two resonant peaks at high and low frequencies show a blue shift as the Dirac semimetal Fermi level increases from 64 meV to 70 meV. Moreover, for a Dirac semimetal Fermi level of 70 meV, as the substrate dielectric thickness increases from 19 μm to 22 μm, the resonant peak at low frequency does not shift, whereas that at high frequency exhibits a red shift.