Sarkar Sambit, Padhy Abhishek, Nayak Chittaranjan
Appl Opt. 2022 Oct 10;61(29):8613-8623. doi: 10.1364/AO.472854.
The optical absorption enhancement of graphene is of significant interest due to its remarkable applications in optical devices. One of the most useful methods is placing graphene in an asymmetric Fabry-Perot cavity made of one-dimensional dielectric multilayers forming two mirrors. In that regard, using the transfer matrix method, we have explicitly calculated the required periodicity of the front photonic multilayer mirror to maximize the absorption in the graphene for any given combination of material types and number of layers. Then we studied the equivalence between these structural configurations and those with arbitrary periodicity but with defects, where the equivalence holds when =,∈. These defects are introduced via layer position alterations, based on which we propose an optimization algorithm to maximize absorption in structures having a cavity with an arbitrary periodicity. Numerical calculations are given for dielectric material combinations of TiO/SiO and TaO/SiO, and to understand the behavior of these optimized structures for any general combination of material types, the mapping of their calculated front mirror periodicity for a range of refractive indices of the two material types has been studied.
由于石墨烯在光学器件中的显著应用，其光吸收增强备受关注。最有用的方法之一是将石墨烯置于由形成两个反射镜的一维介质多层膜构成的非对称法布里 - 珀罗腔中。在这方面，我们使用转移矩阵法，针对任何给定的材料类型和层数组合，明确计算了前光子多层反射镜所需的周期，以最大化石墨烯中的吸收。然后我们研究了这些结构配置与具有任意周期但有缺陷的结构之间的等效性，当 =,∈时等效性成立。这些缺陷通过层位置改变引入，基于此我们提出一种优化算法，以最大化具有任意周期腔的结构中的吸收。给出了TiO/SiO和TaO/SiO介电材料组合的数值计算，并且为了理解这些优化结构对于任何一般材料类型组合的行为，研究了它们针对两种材料类型一系列折射率计算出的前反射镜周期的映射。
