A Review on Structural Colors in Nature in the focus of Diffraction Grating

We live in a nature full of different colors around us. Different areas of science were interested understanding the means of colors been produced in nature. Three main sources have been identified for nature’s colors: pigments, structural colors and bioluminescence. Structural colors are a different way in producing color which is not based on pigments. Many various types of creatures such as beetles, butterflies and peacock feather show bright and attractive colors based on structural colors. Structural color is a special one, which is the color produced from complex interaction between light and sophisticated nano- or micro-structures. The most common mechanisms of structural colors are film interference, diffraction grating, scattering and photonic crystals. Film interference is the mostly used one. The mechanisms mentioned are used independently or combined with each other in nature. Along with animals which are best known for structural colors, there are many examples of plants in case too. This paper presents an overview of various relevant mechanisms in nature and focus on diffraction grating in details. Diffraction gating is rare than other methods and produces iridescent colors. Some examples of it have been recognized in opals, beetles, butterflies and some plants like hibiscus and tulip flowers.