A semianalytically synthesized ultrathin photolithographic metagrating for sub-THz beam splitting

Compact and efficient devices for radiation beam manipulation are in increasing demand by terahertz technologies. Herein, we introduce an ultrathin metal-polymer photolithographic metagrating operating as a transmissive beam splitter with a wide refraction angle of 58^∘ at sub-THz frequencies. Harnessing this recently proposed complex media platform, composed of sparse periodic arrays of meta-atoms, constraints of conventional metasurfaces with densely packed unit cells can be alleviated. The devised splitter, synthesized semianalytically and demonstrated experimentally, features deeply subwavelength thickness due to the unique manufacturing process employed, serving as a promising alternative to thick waveguide-based metagratings previously reported for this frequency range.