Research Centre for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.
Nanotechnology. 2012 Nov 9;23(44):444007. doi: 10.1088/0957-4484/23/44/444007. Epub 2012 Oct 18.
In this paper, we show that a localized surface plasmon polariton in a plasmonic sandwich structure made of a (metal elliptical disc)/(dielectric spacer)/(metal film) can be used as an efficient angle-independent polarizer in the mid-infrared wavelength regime. The elliptical disc structure is characterized by using a Fourier transform infrared spectrometer and simulated via the rigorous coupled wave analysis (RCWA) method. For the optimum design, we can obtain a degree of polarization of 99% both experimentally and theoretically. A high extinction ratio between 20 and 40 dB can be obtained by changing the axis ratio of the elliptical disc between 0.65 and 0.85. The wavelength of polarized light can be tuned in a wide range by changing the structural parameters. The plasmon-polariton band structures of the elliptical disc structure for both TM and TE polarizations are also studied theoretically via RCWA.
在本文中，我们展示了由（金属椭圆盘）/（介电间隔物）/（金属膜）组成的等离子体三明治结构中的局域表面等离激元可以用作中红外波长范围内的高效角无关偏振器。椭圆盘结构的特点是使用傅里叶变换红外光谱仪和严格耦合波分析（RCWA）方法进行模拟。对于最佳设计，我们可以在实验和理论上都获得 99%的偏振度。通过将椭圆盘的纵横比在 0.65 到 0.85 之间改变，可以获得 20 到 40 dB 的高消光比。通过改变结构参数，可以在很宽的波长范围内调谐偏振光的波长。还通过 RCWA 从理论上研究了 TM 和 TE 两种偏振光的椭圆盘结构的等离子体极化激元能带结构。
