title: Broadband and chiral binary dielectric meta-holograms.
abstract: Subwavelength structured surfaces, known as meta-surfaces, hold promise for future compact and optically thin devices with versatile functionalities. By revisiting the concept of detour phase, we demonstrate high-efficiency holograms with broadband and chiral imaging functionalities. In our devices, the apertures of binary holograms are replaced by subwavelength structured microgratings. We achieve broadband operation from the visible to the near infrared and efficiency as high as 75% in the 1.0 to 1.4 μm range by compensating for the inherent dispersion of the detour phase with that of the subwavelength structure. In addition, we demonstrate chiral holograms that project different images depending on the handedness of the reference beam by incorporating a geometric phase. Our devices' compactness, lightness, and ability to produce images even at large angles have significant potential for important emerging applications such as wearable optics.
authors.affiliation: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Khorasaninejad
authors.affiliation: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.; CNR-SPIN Sede secondaria di Napoli, Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, Napoli 80126, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ambrosio
authors.affiliation: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.; University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Pritpal
authors.initials: P
authors.lastname: Kanhaiya
authors.affiliation: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
mesh_terms: D004867:Equipment Design; D006696:Holography / Q000295:instrumentation / Q000379:methods; D055096:Optical Devices; D055095:Optics and Photonics; D013499:Surface Properties
keywords: Optics; dispersionless; hologram; metasurface