Infrared surface plasmon resonance in a subwavelength metallic grating under illumination at a large incidence angle

Abstract

Under the condition of illumination at a large incidence angle, surface plasmon (SP) resonances in the conventional Kretschmann configuration occur in the visible wavelength region. In this paper, we show that a subwavelength metallic binary grating that was specifically designed can induce IR SP resonance (SPR) effectively under the same illumination condition. We analyze the structural controllability of IR SPR by subwavelength metallic binary gratings and propose an optimal design of subwavelength grating structures for IR SPR under illumination at a large incidence angle. A numerical design method combining the rigorous coupled-wave analysis and the genetic algorithm is devised. (c) 2011 Optical Society of America