Abstract
A semiconductor photonic crystal and its application to functional devices are described. The main feature of the crystal is that it has a photonic band gap and we can realize various functions, such as waveguides, cavities and so on, only by introducing artificial defects in the crystal. As one of the examples, we describe here a trapping and emission of photons by a single defect in two-dimensional (2 D) photonic crystal slab. We show the tunability of trapping wavelength by defect engineering and the possibility to realize ultra-small channel drop filters for WDM optical communication system. As another example, we show the band edge engineering, where we demonstrate that 2 D coherent lasing oscillation can be achieved by using the 2 D photonic crystal.
