Open AccessEffects of a butterfly scale microstructure on the iridescent color observed at different angles
Author(s) -
Haruna Tada,
Seth E. Mann,
Ioannis N. Miaoulis,
Peter Y. Wong
Publication year - 1999
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.5.000087
Subject(s) - iridescence , specular reflection , optics , structural coloration , butterfly , microscale chemistry , reflection (computer programming) , reflectivity , materials science , light reflection , total internal reflection , physics , photonic crystal , biology , ecology , mathematics education , mathematics , computer science , programming language
Multilayer thin-film structures in butterfly wing scales produce a colorful iridescence from reflected sunlight. Because of optical phenomena, changes in the angle of incidence of light and the viewing angle of an observer result in shifts in the color of butterfly wings. Colors ranging from green to purple, which are due to nonplanar specular reflection, can be observed on Papilio blumei iridescent scales. This refers to a phenomenon in which the curved surface patterns in the thin-film structure cause the specular component of the reflected light to be directed at various angles while affecting the spectral reflectivity at the same time by changing the optical path length through the structure. We determined the spectral reflectivities of P. blumei iridescent scales numerically by using models of a butterfly scale microstructure and experimentally by using a microscale-reflectance spectrometer. The numerical models accurately predict the shifts in spectral reflectivity observed experimentally.