Tuning the focusing spot of plasmonic nanolens by aspect ratio under linear polarization

【摘要】 A new plasmonic nanolens that can be tuned by varying the circular structure into an elliptical annulus and the aspect ratio from 1 to 0.1 and 1 to 2,respectively,is proposed.Using the rigorous finite-difference and time-domain algorithm,we find that when the aspect ratio ranges from 1 to 0.1,a good linear relationship exists between the aspect ratio and focusing spot size at the full-width at half-maximum in the x- and y-directions,respectively.The corresponding calculated FWHM ranges from 96×126(nm) to 15×52(nm)(Full Width at Half Maximum).更多还原

【Abstract】 A new plasmonic nanolens that can be tuned by varying the circular structure into an elliptical annulus and the aspect ratio from 1 to 0.1 and 1 to 2,respectively,is proposed.Using the rigorous finite-difference and time-domain algorithm,we find that when the aspect ratio ranges from 1 to 0.1,a good linear relationship exists between the aspect ratio and focusing spot size at the full-width at half-maximum in the x- and y-directions,respectively.The corresponding calculated FWHM ranges from 96×126(nm) to 15×52(nm)(Full Width at Half Maximum).更多还原