CHAPTER 2: Stop‐Bands in Photonic Crystals: From Tuning to Sensing

In this chapter, we first introduced abundant structural colors and variable structural colors in nature. Inspired by the strategies that animals change their structural colors in response to the surrounding environment, our group developed a series of process for constructing tunable photonic crystal by coupling functional molecules, colloidal particle assembly and microfabricating technology. Based on the reversible response of functional molecules, such as photochromic dyes and liquid crystal, not only the stop‐band shift and the intensity change at the stop‐band were realized, but also switchable birefringent photonic crystal and reversible reflection photonic crystal were achieved. Our group also developed novel magnetically tunable photonic crystal, whose stop‐band tuning range covered the entire visible spectrum as well as a fast and fully reversible response. On the other side of tunable photonic crystals, sensing external stimuli by photonic crystals were presented in this chapter. Some physical, chemical and biological sensors was prepared by designing components and structures of photonic crystals in our group.