Highly Efficient Focusing of Terahertz Waves with an Ultrathin Superoscillatory Metalens: Experimental Demonstration

The performance of an ultrathin (thickness < 0.04λ 0) metasurface superoscillatory lens (metaSOL) is experimentally demonstrated in the terahertz (THz) range. metaSOL designed using two different hexagonal unit cells to improve efficiency and properties conventional transparent–opaque zoning approach. focusing metastructure produces, at a frequency f exp = 295 GHz, sharp focal spot 8.9λ away from its output surface with transversal resolution 0.52λ (≈25% below limit imposed by diffraction), power enhancement 18.2 dB, very low side lobe level (−13 dB). Resolution diffraction broad fractional operation bandwidth 18%. capabilities proposed show potential use range applications such as THz imaging, microscopy, communications.