Ohnuki Ryosuke, Kobayashi Yuka, Yoshioka Shinya
Graduate School of Science and Technology, Tokyo University of Science, Yamazaki, Noda 278-8510, Japan.
Phys Rev E. 2022 Jul;106(1-1):014123. doi: 10.1103/PhysRevE.106.014123.
Brilliantly colored butterflies and weevils are known to utilize photonic crystals for their coloration. Interestingly, the morphology of such crystals made of cuticle is based on triply periodic minimal surfaces such as gyroid and diamond surfaces. Recently, a different minimal-surface-based photonic crystal, the I-WP surface, was discovered inside the scale of a longhorn beetle. The letter I is derived from expressing the body center symmetry and WP is derived from a wrapped package. It was reported that the brilliant green color is produced by the photonic band gap existing along the [110] direction of this crystal. In this study, the polarization dependence of the reflection from this photonic crystal was investigated. A peculiar reflectance spectrum with two peaks was observed under the crossed polarizers. This characteristic is theoretically reproduced by calculating the reflectance from a finite-sized photonic crystal, and the spectral shape is explained based on the symmetry of the electromagnetic modes. In addition, inspired by this longhorn beetle, a photonic crystal structure consisting of colloidal particles is proposed, which has a similar polarization effect.
众所周知，色彩斑斓的蝴蝶和象鼻虫利用光子晶体来呈现色彩。有趣的是，这种由角质层构成的晶体的形态基于三重周期极小曲面，如类螺旋体和菱形曲面。最近，在一种天牛的鳞片内部发现了一种不同的基于极小曲面的光子晶体，即I-WP曲面。字母I源自其体心对称性，WP源自包裹的封装。据报道，这种晶体沿[110]方向存在光子带隙，从而产生鲜艳的绿色。在本研究中，对该光子晶体反射的偏振依赖性进行了研究。在交叉偏振器下观察到具有两个峰值的奇特反射光谱。通过计算有限尺寸光子晶体的反射率，从理论上再现了这一特性，并基于电磁模式的对称性解释了光谱形状。此外，受这种天牛的启发，提出了一种由胶体颗粒组成的光子晶体结构，它具有类似的偏振效应。
