Optical Properties of Bioinspired Hemispherical Structures

The most vivid colors in nature arise from the interaction of light with surfaces that exhibit periodic structure on the micro- and nanoscale. In the wings of butterflies, for example, a combination of multilayer interference, optical gratings, photonic crystals and other optical structures gives rise to complex color mixing. Although the physics of structural colors is well understood, it remains a challenge to create artificial replicas of natural photonic structures [1-3]. Here we use a combination of microfabrication techniques, to fabricate hemispherical photonic structures that mimic the color mixing effect found on some natural species. The idea of this work is to show that it is possible to perform laboratory surfaces with hemispherical cavities whose properties are similar to these natural structures.