Fu Ya-Nan, Zhang Xin-Qun, Zhao Guo-Zhong, Li Yong-Hua, Yu Jia-Yi. A broadband polarization converter based on resonant ring in terahertz regionJ. Acta Physica Sinica, 2017, 66(18): 180701. DOI: 10.7498/aps.66.180701