Preparation of 3D photonic crystals

Three-dimensional photonic crystals, also known as band gap materials, have broad potential applications in the area of optical devices, biochemical sensors, information transmission and storage, etc. Since the concept of 3D photonic crystals was first proposed in 1987, scientists have devoted themselves to the preparation of 3D photonic crystals with different materials and different topologies in various methods. In this article, various methods reported in recent years are reviewed and divided into three types, " top-down method ", " bottom-up method " and "template-assisted method". Representative examples is given of every method, and its advantage, shortcoming and applicable scope are evaluated.