Creation of Radiative Characteristics by Control of Surface Nano-structure

本研究的目的是研究通过在固体表面上构建纳米结构来创建光学功能表面的可能性。在本研究的第一年，我们开发了一种预测纳米结构表面辐射特性的数值方法。该数值方法是求解麦克斯韦方程组的有限元方法，给出了具有纳米结构表面的物体散射辐射的二维散射电场。该数值代码适用于具有多种纳米结构的表面。证明了数值方法在预测纳米结构表面辐射特性方面的适用性。该研究题为“大闪蝶尺度辐射特性的数值研究”，发表在《热科学与工程》杂志上。第二年，我们用数值方法预测了一种与大闪蝶翅膀具有相同辐射特性的表面纳米结构。为了评价表面的辐射特性，研制了一种表面双向反射测量系统。该系统具有氩离子和氦氖两种激光器，能够测量458nm、488nm、514nm和633nm四个波长的双向反射。利用该系统测量了“大闪蝶”翅膀的辐射特性，而不是预测的表面，因为表面无法制作。我们将通过对大闪蝶翅辐射特性的测量结果与数值预测结果的比较来评价目前的数值方法。

The purpose of this study is to examine the possibility for creating an optically functional surface by constructing nano-structure on a solid surface. In the first year of this study, a numerical method for predicting radiative characteristics of a surface with nano-structure has been developed. This numerical method is a finite element method (FEM) for solving the Maxwell Equations and gives a 2-dimensional scattering electric field of radiation scattered by an object with nano-structure surface. This numerical code is applicable for surfaces with several nano-structure. The applicability of the numerical method for predicting radiative characteristics of a surface with nano-structure has been demonstrated. This study was entitled "Numerical Investigation for Radiative Characteristics of a scale of Morpho butterfly" and published in "Thermal Science and Engineering."In the second year, we predicted a nano-structure of surface that has the same radiative characteristics as the wing of Morpho butterfly by using the numerical method. To evaluate the radiative characteristics of the surface, a measurement system for bi-directional reflection of a surface has been developed. The system has two kinds of Laser, Ar ion and He-Ne and is capable of measuring the bi-directional reflection at four wavelength of 458 nm, 488 nm, 514 nm and 633 nm. By using the system, the radiative characteristics for the wing of "Morpho didius" instead of the predicted surface has been measured, because the surface could not be made. We are going to evaluate the present numerical method by comparing the measured results with the numerical predictions for radiative characteristics of the wing of Morpho didius.