Abstract
We discuss an ultimate light-emission control method by using a two-dimensional photonic bandgap. Calculations predict that a spontaneous emission coupled to the slab modes, which is strongly confined within the slab plane, is inhibited. The saved energy efficiently becomes a spontaneous emission that is coupled to the vertical modes. Controlling the spontaneous emission is experimentally demonstrated by measuring timeresolved photoluminescence spectra from GaInAsP quantum-well samples. The suppression of non-radiative processes that compete the spontaneous emission is achieved by the introduction of InAs quantum dots, which can confine carriers in three dimensions. An artificial point-defect cavity introduced in the photonic crystal can lead to a cavity-mode emission at an extremely low excitation density. Our results demonstrate the realization of an ideal two-dimensional photonic-bandgap environment, and open up possibilities for various applications of photonic crystals using spontaneous-emission phenomena.
