Active lasing from organic colloidal photonic crystals

Abstract

This Highlight provides a brief review of recent progress in the field of colloidal crystals (CCs) combined with functional organic materials for active lasers. Colloidal microparticles have the intrinsic capability to form self-organized 3D ordered structures of microparticles, so-called CCs. From a technological perspective, it is of prime importance to fabricate CCs with photonic band gaps (PBGs) in a visible range. When a light-emitting dye is embedded in the CCs, optical excitation causes the laser emission by the PBG effect. Interestingly, such laser emission can be controlled by utilizing the functional controllability of organic materials. This article covers the background of research into CCs as photonic crystals, and highlights intriguing precedents of active organic CC lasers in response to external stimuli.