We report that a metal-dielectric-metal cavity with a perforated top metallic filn shows a remarkable polarizationselective collimation effect through reflection on the perforated film.According to simulations,such pl...We report that a metal-dielectric-metal cavity with a perforated top metallic filn shows a remarkable polarizationselective collimation effect through reflection on the perforated film.According to simulations,such plasmonic cavities can achieve nearly perfect absorption (R<1.5%) of a transverse magnetic (TM) wave at an optimized incident angle while nearly perfect reflection (R~100%) at normal incidence.A very wide incident angle range (approximately 15°-65°) is found to exhibit a high absorption ratio exceeding over 70%.In contrast,for a transverse electric (TE) wave,the plasmonic cavities remain highly reflective (R~100%) regardless of the incident angles.We elucidate that this polarization- and angle-dependent behavior arises from an even-order (N =2) horizontal Fabry-Perot (FP) resonant mode inside the plasmonic cavity.This effect may find potential applications for angle filtering of polarized divergent light beams in optics.展开更多
基金Supported by the National Basic Research Program of China Grant No 2009CB929300the National Natural Science Foundation of China under Grant Nos 10804019,11174055 and 11174057,Shanghai Science and Technology Committee(No 09dj1400103).
文摘We report that a metal-dielectric-metal cavity with a perforated top metallic filn shows a remarkable polarizationselective collimation effect through reflection on the perforated film.According to simulations,such plasmonic cavities can achieve nearly perfect absorption (R<1.5%) of a transverse magnetic (TM) wave at an optimized incident angle while nearly perfect reflection (R~100%) at normal incidence.A very wide incident angle range (approximately 15°-65°) is found to exhibit a high absorption ratio exceeding over 70%.In contrast,for a transverse electric (TE) wave,the plasmonic cavities remain highly reflective (R~100%) regardless of the incident angles.We elucidate that this polarization- and angle-dependent behavior arises from an even-order (N =2) horizontal Fabry-Perot (FP) resonant mode inside the plasmonic cavity.This effect may find potential applications for angle filtering of polarized divergent light beams in optics.
