Abstract-Demonstration of a highly efficient terahertz flat lens employing tri-layer metasurfaces

Chun-Chieh Chang, Daniel Headland, Derek Abbott, Withawat Withayachumnankul, and Hou-Tong Chen

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-42-9-1867&origin=search

We demonstrate a terahertz flat lens based on tri-layer metasurfaces allowing for broadband linear polarization conversion, where the phase can be tuned through a full 2𝜋$2\pi$ range by tailoring the geometry of the subwavelength resonators. The lens functionality is realized by arranging these resonators to create a parabolic spatial phase profile. The fabricated 124-μm-thick device is characterized by scanning the beam profile and cross section, showing diffraction-limited focusing and ∼68%$\sim 68\%$ overall efficiency at the operating frequency of 400 GHz. This device has potential for applications in terahertz imaging and communications, as well as beam control in general.

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