Nearly perfect resonant absorption and coherent thermal emission by hBN-based photonic crystals
Nearly perfect resonant absorption and coherent thermal emission by hBN-based photonic crystals
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DOI：
10.1364/oe.25.031970
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发表时间：
2017-12-11
期刊：
影响因子：
3.8
通讯作者：
Ozbay, Ekmel
中科院分区：
文献类型：
--
作者：
Hajian, Hodjat;Ghobadi, Amir;Ozbay, Ekmel
在本文中，我们用数值方法证明了中红外近完美的共振吸收和相干热发射的偏振和宽角区使用多层设计的无图案的薄膜的六方氮化硼（hBN）。在这些优化的结构中，hBN的膜被转移到由KBr和Ge的交替层组成的一维光子晶体（1D PC）的顶部上的Ge间隔层上。根据我们的分析和数值计算结果之间的完美协议，我们发现，所提到的基于hBN的一维PC的光学特性是由于由PC支持的局域光子模式和hBN薄膜的声子模式之间的强耦合。这些耦合模式被称为Tamm声子。此外，我们的研究结果表明，可以通过改变hBN和间隔层的厚度的共振吸收红移或蓝移。本文所得到的结果是有益的设计相干热源，光吸收器，和传感器工作在6.2 μ m至7.3 μ m范围内的一个宽的角度范围和两个偏振。这种多层设计的平面和光刻自由性质是使其成为大规模兼容设计的突出因素。(C)根据OSA开放获取出版协议的条款，2017年美国光学学会
In this paper, we numerically demonstrate mid-IR nearly perfect resonant absorption and coherent thermal emission for both polarizations and wide angular region using multilayer designs of unpatterned films of hexagonal boron nitride (hBN). In these optimized structures, the films of hBN are transferred onto a Ge spacer layer on top of a one-dimensional photonic crystal (1D PC) composed of alternating layers of KBr and Ge. According to the perfect agreements between our analytical and numerical results, we discover that the mentioned optical characteristic of the hBN-based 1D PCs is due to a strong coupling between localized photonic modes supported by the PC and the phononic modes of hBN films. These coupled modes are referred as Tamm phonons. Moreover, our findings prove that the resonant absorptions can be red-or blue-shifted by changing the thickness of hBN and the spacer layer. The obtained results in this paper are beneficial for designing coherent thermal sources, light absorbers, and sensors operating within 6.2 mu m to 7.3 mu m in a wide angular range and both polarizations. The planar and lithography free nature of this multilayer design is a prominent factor that makes it a large scale compatible design. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement