Angular dependence of structural fluorescent emission from the scales of the male butterfly Troïdes magellanus (Papilionidae)

Abstract

This paper reveals an enhanced fluorescence in the hindwings of the male Troïdes magellanus, due to the confinement of fluorophores in a three-dimensional photonic structure. It is characterized by a spatial variation of the emission intensity and coloration. It also reveals the role of the structure on the emission and reflection complementary processes. We focus on the experimental analysis of these phenomena by means of a morphological study, a reflection characterization, and an emission characterization. Collecting and analyzing data over every emerging direction was important in this work. A theoretical approach is proposed to explain the experimental observations.