Characteristics of a photonic bandgap single defect microcavity electroluminescent device

A microcavity surface-emitting coherent electroluminescent device operating at room temperature under pulsed current injection is described. The micro cavity is formed by a single defect in the center of a 2-D photonic crystal consisting, of a GaAs-based heterostructure. The gain region consists of t wo 70- Angstrom compressively strained In0.15Ga0.85As quantum wells, which exhibit a spontaneous emission peak at 940 nm. The maximum measured output power from a single device is 14.4 muW. The near-field image of the output resembles the calculated TE mode distribution in a single defect microcavit y. The measured far-field pattern indicates the predicted directionality of a microcavity light source. The light-current characteristics of the devic e exhibit a gradual turn-on, or a soft threshold, typical of single- or few -mode microcavity devices. Analysis of the characteristics with the carrier and photon rate equations yields a spontaneous emission factor beta approx imate to0.06.