Effectiveness of Thin Films in Lieu of Hyperbolic Metamaterials in the Near Field

We show that the near-field functionality of hyperbolic metamaterials (HMM), typically proposed for increasing the photonic local density of states (LDOS), can be achieved with thin metal films. Although HMMs have an infinite density of internally propagating plane-wave states, the external coupling...

Full description

Bibliographic Details
Main Authors: Miller, Owen D., Johnson, Steven G., Rodriguez, Alejandro W.
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:en_US
Published: American Physical Society 2014
Online Access:http://hdl.handle.net/1721.1/86335
https://orcid.org/0000-0001-7327-4967
https://orcid.org/0000-0003-2745-2392
Description
Summary:We show that the near-field functionality of hyperbolic metamaterials (HMM), typically proposed for increasing the photonic local density of states (LDOS), can be achieved with thin metal films. Although HMMs have an infinite density of internally propagating plane-wave states, the external coupling to nearby emitters is severely restricted. We show analytically that properly designed thin films, of thicknesses comparable to the metal size of a hyperbolic metamaterial, yield an LDOS as high as (if not higher than) that of HMMs. We illustrate these ideas by performing exact numerical computations of the LDOS of multilayer HMMs, along with their application to the problem of maximizing near-field heat transfer, to show that single-layer thin films are suitable replacements in both cases.