表面等离子体可以将光子局域在金属表面附近,并形成很强的近场能量密度,可以大大提高金属表面附近分子的发光效率和光电转换吸收材料的利用率,从而提高发光器件和光电转换器件的效率.本文研究了在一维周期性金属一介质混合结构的光栅中表面等离子体激元的耦合条件,给出了耦合效率随着结构和填充因子的变化,并证明了在光栅的填充因子较高以至光栅的金属间隔较小时,光子耦合成为表面等离子体的效率较高,可以达到94%以上.
Surface plasmon polaritons can localize the photons near the metal surface, forming a strong near-field energy density, which affects the efficiency of illumination for molecules and the coefficient of utilization for optical-voltage materials near the metal surface. We analyze the absorption spectrum for the metal-insulator hybrid structure grating and give out the surface plasmon coupling condition according to structure and filling factor. We prove that when filling factor is high enough to form a tiny gap between grating elements, the efficiency for photons to be coupled into surface plasmon polaritons can reach above 94%.