Continuously tunable laser emission from a wedge-shaped organic microcavity

We present an organic microcavity laser with wide tunability in the range of 595-650 nm, having a threshold as low as 2 nJ/pulse. The active medium consists of the organic composite tris(8-hydroxy quinoline) aluminum (Alq(3)) and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) embedded in between two distributed Bragg reflectors. The inhomogeneously broadened emission from DCM is exploited for lasing by means of a tunable Fabry-Perot-type interferometer. Continuous tuning is achieved by varying the thickness of the active layer. The device shows a high photostability under direct excitation in the absorption band of the guest molecule, thus, allowing to monitor the optical gain spectrum of the active medium. (c) 2008 American Institute of Physics.