We propose a flat lensing effect using a periodic loss-modulated material. In particular, we consider a two-dimensional square and rhombic arrangement of lossy cylinders embedded in a host media with the same refractive index. The effect is predicted by the dispersion curves obtained by a coupled mode expansion of Maxwell equations and by numerical beam propagation experiments. From both analytical and numerical studies, we show that, for a range of frequencies, light beams undergo negative diffraction on propagation through the loss-modulated medium, providing a window of high transmission. The phase shifts accumulated by negative diffraction within the structure are then compensated by normal diffraction, leading to substantial focalization beyond it.
Missatge de l'editor: This paper was published in Journal of the Optical Society of America B and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/josab/abstract.cfm?uri=josab-30-10-2684. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
CitationPradeep, N. [et al.]. Flat lensing by periodic loss-modulated materials. "Journal of the Optical Society of America B. Optical physics", 23 Setembre 2013, vol. 30, núm. 10, p. 2684-2688.
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