可见光区一维光子晶体纳米膜偏振带通滤波器的设计

应用一维时域有限差分方法研究各种条件下一维二元光子晶体的偏振带通滤波特性,具体数值分析了掺杂层位置、厚度、电磁参数、入射角度四种因素对偏振滤波特性的影响.数值结果表明传统意义上的光学多层膜是一维二元光子晶体在光学厚度满足四分之一波长时的特例;可见光区的偏振滤波器的窄带滤波特性与掺杂层的位置有关,掺杂层在整个膜中间位置时偏振分离效果好,掺杂层的厚度与周期层厚度相差越大则分离效果越好,两组元折射率相差越大越易形成禁带,入射角越大禁带越窄,偏振的分离度越好.特别是P偏振局域模更多;在线度参数相同的情况下介质电磁参数对禁带有较大影响,禁带只有在两组元折射率相差越大才能形成,介质损耗同样是不可忽略的因素;光源的入射角对禁带有重大影响.本文的研究对光子器件的设计有一定的指导作用.

Design of polarization band-pass filter of one-dimensional photonic crystal nanometer film in the range of visible light

One-dimensional Finite-difference Time-domain method (1-D FDTD) is used in the study and design of polarization filter of one-dimensional photonic crystal nanometer film in the range of visible light. The numerical results indicate that traditional optical multi-layer films are the special case of one-dimensional binary photonic crystals. The filter properties of one-dimensional binary photonic crystals are dependent on a variety of factors, such as the position and thickness of doping layer, the electromagnetic parameters and incident angles. When the doping layer is in the middle of the film, the effect of polarization separation is the best. The larger the difference of thickness between doping layer and periodic layer is, the better the effect of polarization separation is. The forbidden band can be formed if the difference between the refraction indices of two-component is big enough. The incident angle of light and the materials loss both take effect on the filter properties of above structure. All the results play an important role in future design of photonic device.