A metal slit array arranged along a semicircular surface achieving subwavelength optical beam focusing along the lateral direction is proposed. Taking into consideration surface plasmon polaritons that pass through a metal slit array, we design the array with a curvature. By use of a genetic algorithm, the size of the metal slit and the corresponding curvature are to be determined. Based on our metal slit array configuration, the full width at half-maximum can be achieved on a subwavelength scale.
© 2010 Optical Society of America
Original Manuscript: August 13, 2009
Revised Manuscript: November 19, 2009
Manuscript Accepted: November 21, 2009
Published: December 14, 2009
Vol. 5, Iss. 6 Virtual Journal for Biomedical Optics
Dawoon Choi, Yongjun Lim, Sookyoung Roh, Il-Min Lee, Jaehoon Jung, and Byoungho Lee, "Optical beam focusing with a metal slit array arranged along a semicircular surface and its optimization with a genetic algorithm," Appl. Opt. 49, A30-A35 (2010)