Nanometer scale light focusing with high cavity-enhanced output

Marianne Consonni (1, 2) , Jérôme Hazart (1) , Gilles Lerondel (2) , Alexandre Vial (2)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique

Efficient nanoscale optical focusing is demonstrated in double-structured thin metallic films supporting both surface plasmons and cavity eigenmodes. Numerical simulations show that efficient mode coupling can dramatically enhance the transmission of a subwavelength slit. For a spot size of ∼λ/10, the cavity induced enhancement is about an order of magnitude, leading to a final structure output (transmitted power/incident power) of ∼30%. Results are discussed in terms of cavity-slit mode matching and photon trapping within the cavity.

Keywords: Electromagnetism; Plasmons; Microscopy; Gratings; Transition metals; Fluid mechanics; Electrodynamics; Dielectric properties; Thin films; Optical interference

Domains: Engineering Sciences [physics]; Optics / Photonic; Engineering Sciences [physics]; Micro and nanotechnologies/Microelectronics

Marianne Consonni, Jérôme Hazart, Gilles Lerondel, Alexandre Vial. Nanometer scale light focusing with high cavity-enhanced output. Journal of Applied Physics, 2009, 105 (8), pp.084308. ⟨10.1063/1.3112003⟩. ⟨hal-02405060⟩