Optical filtering properties of subwavelength Tai-chi-shaped metal hole arrays
Optical filtering properties of subwavelength Tai-chi-shaped metal hole arrays
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DOI：
10.1016/j.optcom.2014.11.031
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发表时间：
2015-04
影响因子：
2.4
通讯作者：
Xinlin Wang;Hui Liu;Hui-Chao Luo;Weihua Zhu;Zhiyong Chen;Jun Liu;Wei Guo
中科院分区：
文献类型：
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作者：
Xinlin Wang;Hui Liu;Hui-Chao Luo;Weihua Zhu;Zhiyong Chen;Jun Liu;Wei Guo
采用时域有限差分（FDTD）方法研究了一种由银膜太极孔组成的新型周期亚波长孔阵列的光学特性，并数值计算了飞秒光脉冲激励下的光学传输特性。我们发现，与其他正在考虑的器件相比，这种太极形状的器件具有更好的光学带通滤波特性，例如更窄的通带和在可见光波长范围内更高的透射率。基于电介质-金属界面中表面等离子体共振模式的产生，可以通过改变阵列周期来调节传输的中心波长。我们观察到调谐能力主要取决于沿与入射脉冲偏振方向平行的方向的空间周期。研究还发现，矩形分布的金属孔阵列的透射峰的强度和波长均由入射光的偏振决定。此外，我们还演示了这种太极形孔结构的典型带通滤波特性。在可见光波长范围内，窄通带的半峰全宽 (FWHM) 约为 20 nm。
Finite-difference time-domain (FDTD) method is employed to study the optical properties of a novel kind of periodic subwavelength hole arrays composed of Tai-chi-shaped holes in silver film, and the optical transmission properties of femtosecond optical pulse excitation is numerically calculated. We find that this Tai-chi-shaped device has better optical band-pass filtering properties, such as narrower pass band and higher transmissivity in visible wavelengths range, than other devices under consideration. Based on the generation of surface plasmons resonance mode in the dielectric–metal interface, the center wavelength of transmission can be tuned by changing the array periodicities. We observe that the tune ability mainly depends on the space period along the direction parallel to that of the incident pulse polarization. It is also found that both the strength and the wavelength of the transmission peaks of rectangularly distributed metal hole arrays are determined by the polarization of incident light. Additionally, we demonstrate the typical band-pass filtering properties of this Tai-Chi-shaped holes structure. The full-width at half-maximum (FWHM) of the narrow pass band is about 20 nm in visible wavelengths range.