Transform-limited, narrow-linewidth lasing action in organic semiconductor microcavities

The recent interest in lasing action and stimulated emission in optically pumped thin films of small molecular weight organic semiconductors and polymers (1-5) is opening the door to a new [...]
Lasing action in organic vertical-cavity surface-emitting laser (OVCSEL) structures is demonstrated. Optically pumped OVCSELs with an active layer composed of a thin-film organic semiconductor tris-(8-hydroxyquinoline) aluminum ([Alq.sub.3]) doped with DCM laser dye produced very narrow linewidth (0.2 ± 0.1 angstrom), high-power (3 watts) emission that could be varied in different devices from orange to red. The efficient energy transfer from [Alq.sub.3] to DCM results in a threshold input energy of 300 microjoules per square centimeter. An operational lifetime [is greater than] [10.sup.6] laser pulses was achieved for a device operated well above threshold in atmosphere. The linewidths above threshold are Fourier transform-limited and could potentially be narrowed further.