In this paper, a novel guided-mode resonances (GMRs) based embedded dual-wavelength filter, which had the bilayer gratings located at the two sides of dielectric substrate and arranged at asymmetric position, was investigated and studied theoretically. As compared to symmetric structures that usually provided single wavelength of transmission resonance, as one normal incidence was used for transverse magnetic polarized light, the designed asymmetric structure could generate two remarkable narrow band wavelengths of transmission resonance. The parameters to affect the resonance wavelengths and the transmission resonance Q value (Q = λ/Δλ) of two bands were the distance between the two metallic gratings, the relatively lateral positions of the upper and lower gratings, the number of structure period, the thicknesses of metallic gratings, and the thickness of dielectric film. By optimizing the designed parameters, a GMR device with two resonance wavelengths located at 1239 and 1302 nm showed relative optimal performance because they had high transmission depth (99.9% and 90%) and ultra-narrow transmission bandwidth (2.8 and 1.8 nm) at the two resonance wavelengths. The presented structure can offer a potential route towards dual-band narrow-band filters and refractive index sensors in the near infrared.

本文从理论上研究了一种新型的基于导波模式共振（GMRs）的嵌入式双波长滤波器，该滤波器具有双层光栅位于介电基板的两侧，并布置在非对称位置。与通常提供传输共振的单个波长的对称结构相比，由于横向磁偏振光使用一个法线入射，因此设计的非对称结构可以生成两个显着的窄带传输共振波长。影响两个波段的共振波长和透射共振Q值（Q =λ/Δλ）的参数是两个金属光栅之间的距离，上下光栅的相对侧向位置，结构周期数，金属格栅的厚度 和介电膜的厚度。通过优化设计参数，具有两个谐振波长分别位于1239和1302 nm的GMR器件显示出相对最佳的性能，因为它们在传输波长处具有高传输深度（99.9％和90％）和超窄传输带宽（2.8和1.8 nm）。两个共振波长。提出的结构可以提供一条通往近红外双波段窄带滤光片和折射率传感器的潜在途径。