对金属的复介电常数虚部进行了Kawabata-Kubo(K-K)修正,定量描述了表面等离激元产生的光学散射和吸收特性;利用米氏理论和电偶极子理论计算并分析了光入射到单个椭球状金属纳米微粒产生的消光特性;建立了椭球状纳米微粒周期阵列分布的光学偏振结构模型,利用COMSOL软件模拟计算了可见光到近红外波段的偏振光输出特性。以椭球的有效半径替代球半径,将K-K修正应用于金属椭球阵列结构的有限元模拟。修正后的金属纳米椭球阵列的透过率减小,消光光谱带宽增大,这与实验中单个金属颗粒的宽带强吸收特性趋势一致。

The imaginary part of the complex permittivity of the metal nanoparticle is modified by Kawabata-Kubo (K-K) correction. The optical scattering and absorption characteristics of surface plasmons are quantitatively described. The extinction characteristics of light incident on a single ellipsoid metal nanoparticle are calculated and analyzed by Mie theory and the electric dipole theory. A optical polarization structure model of periodic array of ellipsoidal nanoparticles is established. The output characteristics of polarized light from visible to near infrared bands are simulated and calculated by COMSOL software. K-K correction is applied to finite element simulation of the metal ellipsoid arrays by replacing spherical radius with effective radius of ellipsoid. The modified metal nano-ellipsoid arrays have lower transmittance and wider extinction spectrum bandwidth, which is consistent with the experimental trend of broadband strong absorption characteristics of single metal particles.