Reproduction of Morpho Butterfly's Blue and its Optimization of Characteristics

Morpho-butterfly's brilliant blue is produced from the scale. It contains no blue pigment, but has high reflectivity of the blue coloration, thus the origin of the coloration should be due to the microscopic structure. However, it appears not multi-coloration but blue from excessively wide angle, which contradicts the interference obviously. Recently, the mystery has been explained with a principle given by a peculiar nano-structure. We experimentally proved the principle by fabricating the optical film by controlling the parameters in nanoscale. The artificial film reproduced the basic characteristics of the Morpho-blue, however in detail, showed some differences from the Morpho-butterfly. In order to make it closer to the Morpho-butterfly than the prototype, we attempted to optimize the film by controlling parameters through the consideration of optical simulations and micro-structural observations. By comparing a series of films systematically, the relationship between the parameters and the properties was analyzed, and the optimized parameters were successfully determined.