Appl Opt. 2020 Jul 20;59(21):F85-F93. doi: 10.1364/AO.398832.
Circularly polarized light (CPL) reflections are rare in nature. Only a few animal groups-most notably certain stomatopod crustaceans and certain beetles in the family Scarabaeidae-are known to reflect CPL from incident unpolarized light. Here, we examine five species of metallic scarabs in the genus Chrysina that, to the naked human eye, look remarkably similar. Using a spectropolarimetric reflectometer to characterize the complete Mueller matrix elements of the beetles' elytral surfaces, we found that four of the five species were strongly left-handed circularly polarized (LHCP), and only one scarab species, Chrysina resplendens, had an overall lower degree of polarization and switched from LHCP to right-handed circularly polarized reflectance depending on wavelength.
圆偏振光（CPL）反射在自然界中很少见。只有少数动物群体——最著名的是某些十足目甲壳动物和某些鞘翅目 Scarabaeidae 科的甲虫——已知能从非偏振光中反射 CPL。在这里，我们研究了五种金属金龟子属的 Chrysina 甲虫，从肉眼上看，它们非常相似。使用分光偏振反射计来描述甲虫鞘翅表面的完整 Mueller 矩阵元素，我们发现这五种甲虫中有四种是强烈的左旋圆偏振（LHCP），只有一种金龟子物种 Chrysina resplendens 的整体偏振度较低，并且根据波长从 LHCP 切换到右旋圆偏振反射。
