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A detailed analysis of the optical waveguide modes in organic light emitting diodes (OLEDs) is presented. The modes are compared with respect to their electric field profile, attenuation coefficient and optical confinement factor. The first transversal electric (TE) mode is best suited for an optimized energy transfer from emitting dipoles. The transversal magnetic (TM) modes are characterized by a large plasmon character with high absorption. The propagation constants of distinct modes have been measured in test devices by grating coupling. [Copyright &y& Elsevier]

We present a comparison of different molecular glasses based on the spiro-concept with respect to their photoemission properties. The absorption and emission spectra as well as the photoluminescence quantum yields in solution are characterized. For thin amorphous films, prepared by vacuum vapor deposition, we examined amplified spontaneous emission (ASE) by optical pumping with picosecond pulses at 337 nm. Efficient ASE emission with thresholds of down to 1 μJ/cm2 was observed. [Copyright &y& Elsevier]