Abstract
Terahertz waves are finding important applications in diverse fields, and meanwhile the manipulation of terahertz waves calls for the development of various functional devices. Here, we have designed and fabricated a metagrating-based polarization beam splitter for terahertz waves using the simplified modal method. By only considering two propagation modes and treating the grating as a Mach-Zehnder interferometer, the method can greatly simplify the reverse grating design process. The parameters of the grating are first obtained under the guidance of the simplified modal method and then improved upon by the finite element method. The fabricated device is finally experimentally demonstrated with a terahertz time-domain spectroscopy system. The diffraction efficiencies of the polarization beam splitter at 0.9 THz are measured to be 69 and 63% for TE and TM waves relative to that of a silicon plate, respectively. The corresponding extinction ratios are 12 and 17 dB for TE and TM waves, respectively. The experiment results agree well with the simulations.
Original language | English (US) |
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Journal | Frontiers in Physics |
Volume | 8 |
DOIs | |
State | Published - Oct 15 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-16Acknowledged KAUST grant number(s): OSR-2016-CRG5-2950
Acknowledgements: This work was supported by the National Key Research and Development Program of China (Grant No. 2017YFA0701004), the National Natural Science Foundation of China (Grant Nos. 61775159, 61420106006, 61427814, 61422509, 61735012, and 61505146), the Tianjin Municipal Fund for Distinguished Young Scholars (Grant No. 18JCJQJC45600), and King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) (Grant No. OSR-2016-CRG5-2950).