光子晶体可调谐滤波特性的理论研究

Theoretical study of the tunable optical filter properties based on photonic crystals

用特征矩阵法研究了带缺陷的一维光子晶体的透射性质 ,并提出了新的可调谐光滤波器的概念 .一维光子晶体 (L1 H1 ) m 带有LcH2 (L2 H2 ) n 形式的缺陷时 ,在光子晶体中间出现了窄的透射峰 ,其他级次的干涉峰则随着覆盖层H2 (L2 H2 ) n 周期数的增大而减弱并消失 .当耦合层Lc 厚度变化时 ,在光子晶体禁带边缘附近出现两个高透射率区域 .高透射率区域透射峰的特性由光子晶体和覆盖层的性质决定 .当光子晶体禁带宽度较小时 ,两个高透射率区域接近 ,形成具有约 15 0nm调谐范围的区域 ,因此可制备以一维光子晶体为基础的新型可调谐光滤波器 .

The transmission properties of the one-dimensional photonic crystals with defects were studied using the eigen matrix method, and a new kind of tunable optical filter is proposed in this paper. When the one-dimensional photonic crystals (L 1H 1)m have defects such as L cH 2(L 2H 2)n, there will be a narrow transmission band in the gap of the photonic crystals, meanwhile the other transmission peak will weaken and disappear with the increase of the periodic number of the cover layer. When the thickness of the couple layer changes, there will be two regions with high transmittivity besides the edges of the photonic crystals gap. The properties of the high transmission band depend on the photonic crystals and the cover layers. When the photonic crystals gap is narrowed, the two regions will come near, which results in a wide transmission region about 150 nm. A new kind of tunable optical filter thus can be fabricated based on this phenomenon by the surface micro-mechanical technology.