Optimization of transmission and focusing properties of plasmonic nanolenses
Paper i proceeding, 2011

We consider two kinds of plasmonic nanolenses which focus radially polarized Laguerre-Gauss beam into subwavelength spot. The first one is free-standing opaque metal layer with concentric grooves on both sides [Phys. Rev. Lett. 102, 183902 (2009)]. The second has slits instead of grooves thus concentric rings have to be integrated with dielectric matrix. Constructive interference of far-field radiation of SPPs scattered on the back side of the lenses gives subwavelength size foci approaching the Rayleigh resolution limit. We investigate transmission and focusing properties of considered metal structures. Choice of appropriate metal such as silver, gold, copper or aluminum strongly affects transmission. Parameters of surface structure determine efficient photon-plasmon coupling and plasmon scattering phenomenon thus influence both transmission and focusing effect. Finally, the choice of dielectric function of surrounding medium gives another degree of freedom to fulfill momentum matching condition for resonant photon-plasmon interaction. In this paper, taking into account the above parameters, we show an optimization procedure, which leads to high transmission, tight focal spot and large focal length of the considered plasmonic nanolenses.

Radial polarization

Plasmonics

Plasmonic lens

Författare

P. Wróbel

Uniwersytet Warszawski

Tomasz Antosiewicz

Chalmers, Teknisk fysik, Kondenserade materiens teori

T. Szoplik

Uniwersytet Warszawski

Proceedings of SPIE - The International Society for Optical Engineering

0277786X (ISSN)

Vol. 8070 80700G

Ämneskategorier

Elektroteknik och elektronik

DOI

10.1117/12.886838

ISBN

978-081948660-8