Edalatpour Sheila
Department of Mechanical Engineering and Frontier Institute for Research in Sensor Technologies, University of Maine, Orono, Maine 04469, USA.
Phys Rev E. 2019 Jun;99(6-1):063308. doi: 10.1103/PhysRevE.99.063308.
Near-field thermal emission can be engineered by using periodic arrays of subwavelength emitters. The array thermal emission is dependent on the shape, size, and material properties of the individual elements as well as the period of the array. Designing periodic arrays with desired properties requires models that relate the array geometry and material properties to the near-field thermal emission. In this study, a periodic method is presented for modeling two-dimensional periodic arrays of subwavelength emitters. This technique only requires discretizing one period of the array, and thus is computationally beneficial. In this method, the energy density emitted by the array is expressed in terms of the array's Green's functions. The array Green's functions are found using the discrete dipole approximation in a periodic manner by expressing a single point source as a series of periodic arrays of phase-shifted point sources. The presented method can be employed for modeling periodic arrays made of inhomogeneous and complex-shape emitters with nonuniform temperature distribution. The proposed technique is verified against the nonperiodic thermal discrete-dipole-approximation simulations, and it is demonstrated that this method can serve as a versatile and reliable tool for studying near-field thermal emission by periodic arrays.
通过使用亚波长发射器的周期性阵列，可以对近场热发射进行调控。阵列热发射取决于单个元件的形状、尺寸和材料特性以及阵列的周期。设计具有所需特性的周期性阵列需要将阵列几何形状和材料特性与近场热发射相关联的模型。在本研究中，提出了一种用于对亚波长发射器的二维周期性阵列进行建模的周期性方法。该技术仅需要对阵列的一个周期进行离散化，因此在计算上具有优势。在这种方法中，阵列发射的能量密度用阵列的格林函数来表示。通过将单个点源表示为相移点源的一系列周期性阵列，以周期性方式使用离散偶极近似来找到阵列格林函数。所提出的方法可用于对由具有非均匀温度分布的非均匀和复杂形状发射器组成的周期性阵列进行建模。该技术与非周期性热离散偶极近似模拟进行了验证，结果表明该方法可作为研究周期性阵列近场热发射的通用且可靠的工具。
