title: Subwavelength focusing using a hyperbolic medium with a single slit.
abstract: A hyperbolic dispersion medium with a planar surface that can be used for subwavelength focusing is proposed. By combining the hyperbolic medium in a single slit with diffraction limit width, a laser beam could be focused to a subwavelength spot in the near field. Compared to a conventional superlens, the subdiffraction focusing in this work has higher optical throughput. Using a planar hyperbolic medium, which is actually alternating silver/dielectric multilayers, we showed that the focusing resolution of the designed device is down to ~λ/5 using green light illumination (at a wavelength of 514.5 nm).
authors.affiliation: Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
authors.forename: Guixin
authors.initials: G
authors.lastname: Li
authors.forename: Jensen
authors.initials: J
authors.lastname: Li
authors.forename: Kok Wai
authors.initials: KW
authors.lastname: Cheah