光学学报, 2013, 33 (11): 1105001, 网络出版: 2013-09-17
二维亚波长金属光栅多波长透射滤光片
Transmission Bandpass Filters Based on Two-Dimensional Subwavelength Metallic Gratings
摘要
为实现阵列化、多波长光探测器件的微型化与集成化,设计了一种基于亚波长金属光栅导模共振原理的透射滤光片。利用波导理论分析了二维金属光栅波导对称和非对称两种结构的共振特性,数值仿真分析了光栅各参数如占空比、光栅厚度、侧壁角度等对透射谱线的影响,并给出了结构优化参数范围。研究表明,透射滤光片的峰值波长与半峰全宽(带宽)取决于光栅周期和缓冲层厚度,带宽的调节范围为2~45 nm,最大透射率为81.7%,所设计的滤光片具有偏振无关性,较好地满足了当前微流控芯片、生物传感阵列等微量样品集成化探测的需求。
Abstract
In order to achieve the miniature and integration of the optical devices in multi-wavelength array detection, a novel transmission filter based on subwavelength metallic grating guided mode resonance is proposed. The resonance characteristics of the filters with symmetric and nonsymmetric waveguide structure are theoretically analyzed. The effects of the grating structural parameters on the transmission spectrum are investigated in detail, such as filling factor, grating thickness, the sidewall angle, et al. And the optimal scope of the grating structure is also presented. Simulation results show that the peak position and the full width at half maximum (FWHM) of the filter are attributed to the grating period and the buffer layer. And the FWHM can be adjusted from 2 nm to 45 nm, the maximum transmittance increases to 81.7%. Besides, the transmission spectrum is independent on the polarization of the incident field due to the symmetry of the subwavelength metallic grating. The filters can satisfy the requirements of microfluidic and biosensing and so on.
周文超, 吴一辉, 郝鹏, 刘桂根, 李凯伟. 二维亚波长金属光栅多波长透射滤光片[J]. 光学学报, 2013, 33(11): 1105001. Zhou Wenchao, Wu Yihui, Hao Peng, Liu Guigen, Li Kaiwei. Transmission Bandpass Filters Based on Two-Dimensional Subwavelength Metallic Gratings[J]. Acta Optica Sinica, 2013, 33(11): 1105001.