基于全介质的超表面谐振器热发射相干性研究  

Thermal Emission Coherence Based on All-Dielectric Metasurface Resonators

作　　者：成涛 费天皓 赵欢欢 杨家跃 刘林华 Cheng Tao;Fei Tianhao;Zhao Huanhuan;Yang Jiayue;Liu Linhua(Optics&Thermal Radiation Research Center,Institute of Frontier and Interdisciplinary,Shandong University,Qingdao 266237,Shandong,China;Optics&Thermal Radiation Research Center,School of Energy and Power Engineering,Shandong University,Jinan 250061,Shandong,China)

机构地区：[1]山东大学前沿交叉科学青岛研究院光热辐射研究中心,山东青岛266237 [2]山东大学能源与动力工程学院光热辐射研究中心,山东济南250061

出　　处：《光学学报》2023年第14期300-309,共10页Acta Optica Sinica

基　　金：国家自然科学基金(52076123);山东大学齐鲁青年学者基金(89963031)。

摘　　要：以六方碳化硅(4H-SiC)全介质谐振器为例,借助椭圆偏振实验与有限元电磁模拟系统地研究了温度与结构几何周期对其相干热发射的影响机制。研究结果表明:高温削弱了4H-SiC晶体的介电极化与超表面的相干热发射,而几何周期正向影响表面波传输模的激发与耦合强度,从而影响发射率的空间相干性;二者主要通过改变表面波有效传输长度来调节热发射的相干性。此外,全介质超表面谐振器的高Q值对温度与结构周期有很强的依赖性。所得结果可为相关极化超表面谐振器件在热发射调控领域的应用提供参考。Objective Thermal emission is the most critical optical property in thermal radiation.Precise regulation of the thermal emissivity of materials is essential for practical applications of thermally related devices such as energy harvesting,chemical sensing,and dynamic camouflage.Designing micro-or nanostructured metasurfaces is an effective way to modulate spectral emissivity.Alldielectric metasurfaces supporting surface phonon polaritons(SPhPs)can achieve strong lightmatter interaction with low optical loss and play an essential role in coherent thermal emission.Among them,silicon carbide(SiC)is a promising candidate due to its rich molecular vibrations and thermal phenomena.Numerous studies have successfully efficiently tuned the coherence of thermal emission by constructing SiC metasurface.However,the physical origin of SPhP emission modes in SiC and their coupling mechanism have not been clearly elucidated yet.In addition,temperature affects the emission properties of the material by changing its optical properties.Still,the current lack of data on the hightemperature dielectric function of SiC is not conducive to further expansion in this direction.Therefore,the physical mechanisms regulating the coherent thermal emission of hexagonal SiC(4HSiC)alldielectric metasurfaces are systematically investigated by adjusting the geometric period and temperature.Methods In this paper,the ellipsometric parametersψandΔare obtained with the help of IRVASE MarkⅡspectroscopic ellipsometry(SE),and the temperaturedependent dielectric functions(ε=ε′+iε″)of 4HSiC are derived by fitting the Bspline optical model.The obtained dielectric functions are chosen as input for the finite element modeling(FEM)simulations in the form of interpolation functions.The FEM simulations investigate the emitting mode′s quality and the metasurface′s thermal emission potential in terms of temperature,incidence angle,and structural period.Absorption energy(W)calculations are used to investigate the absorption mechanism of the metasurfa

关 键 词：光谱学 表面声子极化 全介质超表面谐振器 相干热发射 温度 几何周期 

分 类 号：O436[机械工程—光学工程]