title: Tunable subwavelength focusing with dispersion-engineered metamaterials in the terahertz regime.
abstract: We develop a terahertz lens with both subwavelength resolution and tunable far-field focal length by extending the surface plasmon (SP) diffraction theory into spoof SPs of slit-groove-structure terahertz metamaterials. The dispersion properties of terahertz groove structures are engineered in the curved depth profile to produce a directional beaming feature and mimic SPs at the same time. The finite-difference time-domain simulation results confirm that the far-field focal position can be tuned by controlling the curvature of the relative electric field phase distribution profile on the output surface.
authors.affiliation: School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, South Korea.
authors.forename: Jinho
authors.initials: J
authors.lastname: Lee
authors.forename: Kwangchil
authors.initials: K
authors.lastname: Lee
authors.forename: Haesung
authors.initials: H
authors.lastname: Park
authors.forename: Gumin
authors.initials: G
authors.lastname: Kang
authors.forename: Dai-Hyuk
authors.initials: DH
authors.lastname: Yu
authors.forename: Kyoungsik
authors.initials: K
authors.lastname: Kim
mesh_terms: D004738:Engineering / Q000379:methods*; D007909:Lenses; D012542:Scattering, Radiation; D013057:Spectrum Analysis; D013499:Surface Properties