Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
J Exp Biol. 2021 Aug 1;224(15). doi: 10.1242/jeb.242983. Epub 2021 Aug 6.
The dorsal wings of the mother-of-pearl butterfly, Protogoniomorpha parhassus, display an angle-dependent pink, structural color. This effect is created by light interference in the lower lamina of the wing scales, which acts as an optical thin film. The scales feature extremely large windows that enhance the scale reflectance, because the upper lamina of ridges and cross-ribs is very sparse. Characteristic for thin film reflectors, the spectral shape of the reflected light strongly depends on the angle of light incidence, shifting from pink to yellow when changing the angles of illumination and observation from normal to skew, and also the degree of polarization strongly varies. The simultaneous spectral and polarization changes serve a possibly widespread, highly effective system among butterflies for intraspecific communication during flight.
珍珠母蝴蝶 Protogoniomorpha parhassus 的背翅呈现出角度依赖的粉红色结构色。这种效果是由翅膀鳞片下层的光干扰产生的，其作用类似于光学薄膜。鳞片上有非常大的窗口，可以增强鳞片的反射率，因为脊和横肋的上层非常稀疏。对于薄膜反射器来说，特征在于反射光的光谱形状强烈依赖于光入射角，当从正常照射角度到斜角照射和观察角度变化时，从粉红色到黄色的光强反射，并且偏振度也强烈变化。这种同时的光谱和偏振变化可能是蝴蝶在飞行中进行种内交流的一种广泛存在的、非常有效的系统。
