Effect of the number of zones in a one-dimensional plasmonic zone plate lens: simulation and experiment

Chen, Q. (2011) Effect of the number of zones in a one-dimensional plasmonic zone plate lens: simulation and experiment. Plasmonics, 6(1), pp. 75-82. (doi: 10.1007/s11468-010-9171-6)

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Publisher's URL: http://dx.doi.org/10.1007/s11468-010-9171-6

Abstract

A 1D plasmonic zone plate lens (PZPL) consisting of nano-slits within a metal film introduces a phase delay distribution across the planar device surface by a modulation of the slit widths and positions to achieve light focusing. Using the finite-difference time-domain method, the number of zones is found to be a crucial factor for a well-controlled focal length, i.e. at least three zones are necessary for a PZPL exhibiting a focal length in agreement with the design. This conclusion is confirmed by confocal scanning optical microscopy on PZPLs patterned in an aluminium film. In addition, subwavelength light focusing is demonstrated both theoretically and experimentally in a PZPL. A larger PZPL, i.e. more zones, shows a higher resolution. A full full-width half-maximum of 0.37λ in the focal plane is shown theoretically in a PZPL with seven zones. A comparison between the PZPL and the plasmonic Fresnel zone plate shows that PZPLs have a higher contrast at the focus.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Chen, Dr Qin
Authors: Chen, Q.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Plasmonics
Publisher:Springer New York LLC
ISSN:1557-1955
ISSN (Online):1557-1963
Published Online:12 October 2010

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