一维电介质-金属光子晶体的光学特性研究

利用传输矩阵方法，研究了一维电介质-金属光子晶体的光学特性，该光子晶体通过在Si/SiO₂组成的电介质型光子晶体中插入一定厚度Al层形成。计算结果表明，金属层的引入可以有效提高反射效率，[Si(46 nm)/SiO₂(60 nm)/Al(10 nm)/SiO₂(60 nm)]5结构的单位周期传输衰减从[Si(46 nm)/SiO₂(120 nm)]5的7.2 dB增大到了20 dB；可以得到更宽频率范围的全方向反射带隙，例如[Si(46 nm)/SiO₂(60 nm)/Al(30 nm)/SiO₂(60 nm)]5结构即可提供550 nm带宽的全方向反射；同时讨论了金属吸收、金属层厚度及插入位置对其光学特性的影响。这种电介质-金属光子晶体有望作为性能优异的光学反射镜得到应用。

Optical Properties of One-Dimensional Metallodielectric Photonic Crystals

The optical characteristics of one-dimensional metallodielectric photonic crystals(MDPC),constructed by inserting metal aluminum layers of certain thickness into the Si/SiO2 system,were studied theoretically with the transfer matrix method.The results show that the reflection efficiency can be enhanced considerably after the introduction of metallic layers,e.g.the rejection level of each period increased from 7.2 dB([Si(46 nm)/SiO2(120 nm)]5) to 20 dB([Si(46 nm)/SiO2(60 nm)/Al(10 nm)/SiO2(60 nm)]5).In addition,high omnidirectional reflection band with broader width can be obtained,e.g.bandwidth of 550 nm can be offered with [Si(46 nm)/SiO2(60 nm)/Al(30 nm)/SiO2(60 nm)]5.Rules of how the absorption,thickness and position of the metal layers affect the optical characteristics of the MDPC are also discussed.These MDPC structures may be used as compact-size,low-loss and broad-band optical reflectors.