The Hunt for Red Structural Color

Structural color is an optical phenomenon where light reflecting from nanostructures produces color primarily via scattering, interference, and diffraction rather than pigmentation. Structural colors are some of the most brilliant colors in nature, and the blue of the Morpho butterfly is one of the most vivid examples. This project involves computer simulations of nanostructures using the finite-difference time-domain (FDTD) method and modifying the geometry to observe the effects on the spectra and angular distribution of the reflected light. While blue is the most common structural color, we aim to determine why red structural color is so rare in nature and whether nanostructures that generate red structural color can be designed and optimized computationally. Here we present our progress towards understanding structural color and exploring the parameter space of Morpho-inspired nanostructures with a view to simulating structural color that is tunable across the visible spectrum.