A tandem organic light-emitting diode structure, excited electrically in the pulsed domain and confined within a double spatial filter configuration, is observed to emit a low-divergence beam (Delta theta≈2.53 mrad, or ∼1.1 times the diffraction limit) with a near-Gaussian spatial distribution. The emission originates from the laser dye Coumarin 545 T, which is used as a dopant. Spectral coherence was determined by use of a double-slit interferometer. The interferometric distribution from our device approximates the interferometric pattern obtained from well-known lasers emitting at lambda≈540 nm.
© 2005 Optical Society of America
F. J. Duarte, L. S. Liao, and K. M. Vaeth, "Coherence characteristics of electrically excited tandem organic light-emitting diodes," Opt. Lett. 30, 3072-3074 (2005)