Light emission control by photonic crystals

Photonic crystals are novel functional photonic nanostructures with the ability to control optical modes. In this paper, we will present recent progress on the lightemission control by photonic crystals. It has been clearly demonstrated that undesired light emission can be inhibited by the photonic bandgap, whereas desired emission efficiency can be increased. In addition, the light emission phenomena of gallium nitride based photonic crystals and indi-rect-bandgap semiconductor silicon photonic crystals will be discussed.