Tight focus of light using micropolarizer and microlens
Abstract
Using a binary microlens of diameter 14 μm and focal length 532 nm (NA = 0.997) in resist, we focus a 633 nm laser beam into a near-circular focal spot with dimensions (0.35 ± 0.02)λ and (0.38 ± 0.02)λ (λ is incident wavelength) at full width half-maximum intensity. The area of the focal spot is 0.105λ2. The incident light is a mixture of linearly and radially polarized beams generated by reflecting a linearly polarized Gaussian beam at a 100 μm 100 μm four-sector subwavelength diffractive optical microelement with a gold coating. The focusing of a linearly polarized laser beam (the other conditions being the same) is found to produce an elliptical focal spot measuring (0.40 ± 0.02)λ and (0.50 ± 0.02)λ. To our knowledge, this is the first implementation of subwavelength focusing of light using a pair of micro-optic elements (a binary microlens and a micropolarizer).
Citation
Stafeev , S S , O'Faolain , L , Kotlyar , V V & Nalimov , A G 2015 , ' Tight focus of light using micropolarizer and microlens ' , Applied Optics , vol. 54 , no. 14 , pp. 4388-4394 . https://doi.org/10.1364/AO.54.004388
Publication
Applied Optics
Status
Peer reviewed
ISSN
1559-128XType
Journal article
Rights
© 2015 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at http://dx.doi.org/10.1364/AO.54.004388.
Description
Funding: European Research Council (ERC) (337508); Ministry of Education and Science of the Russian Federation (MK-4816.2014.2, NSh-3970.2014.9); Russian Foundation for Basic Research (14-07-31092, 14-07-97039, 14-29-07133, 15-07-01174).Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.