Photonic crystal for gas sensing

Photonic crystal (PhCs) based sensing technology has gained more and more attention because of its obvious advantages in sensitivity, stability, security, miniaturisation, portability, on-line use and remote monitoring. Many PhC sensors have been proposed based on their novel structure and unique optical properties. In this review, we will describe the recent progress in the use of natural and artificial PhC materials for gas/vapor sensing, including Morpho butterfly wings and their mimicry of nanostructures, porous silicon, Bragg stacks, colloidal crystals and inverse opal. Here we will discuss the PhCs with different structures and their respective gas sensing properties, focusing on the description of the functional structure of the PhCs materials and their sensing mechanisms.