Institute for Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, 76131 Karlsruhe, Germany.
Nat Commun. 2015 Apr 22;6:6909. doi: 10.1038/ncomms7909.
The glasswing butterfly (Greta oto) has, as its name suggests, transparent wings with remarkable low haze and reflectance over the whole visible spectral range even for large view angles of 80°. This omnidirectional anti-reflection behaviour is caused by small nanopillars covering the transparent regions of its wings. In difference to other anti-reflection coatings found in nature, these pillars are irregularly arranged and feature a random height and width distribution. Here we simulate the optical properties with the effective medium theory and transfer matrix method and show that the random height distribution of pillars significantly reduces the reflection not only for normal incidence but also for high view angles.
玻璃翼蝶（Greta oto）的名字表明其翅膀是透明的，具有出色的低雾度和在整个可见光谱范围内的低反射率，即使在 80°的大视角下也是如此。这种各向同性的抗反射行为是由覆盖其翅膀透明区域的小纳米柱引起的。与自然界中发现的其他抗反射涂层不同，这些柱子的排列是不规则的，具有随机的高度和宽度分布。在这里，我们使用有效介质理论和转移矩阵方法模拟了光学性质，并表明柱子的随机高度分布不仅显著降低了正入射时的反射率，而且还降低了大视角时的反射率。
