We report on a solid-state laser structure being the organic counterpart of the Vertical External-Cavity Surface-Emitting Laser (VECSEL) design. The gain medium is a poly (methyl methacrylate) film doped with Rhodamine 640, spin-casted onto the HighReflectivity mirror of a plano-concave resonator. Upon pumping by 7-ns pulses at 532 nm, a diffraction-limited beam (M²=1) was obtained, with a conversion efficiency of 43%; higher peak powers (2kW) could be attained when resorting to shorter (0.5 ns) pump pulses. [7,8] or microcavities [9,10]. In the meantime, less attention has been paid to the question of optimizing conversion efficiency, beam quality and power scaling capability. Low-threshold operation and high-output power are indeed incompatible statements in a single device: whereas weak output coupling and small active volume are desirable for low threshold lasing, achieving high output power leads to an optimal transmission for the output coupler [11] and requires keeping the pump fluence to

Stimulated emission in small-molecule organic films at a high dye concentration is generally hindered by fluorescence quenching, especially in the red region of the spectrum. Here we demonstrate the achievement of high net gains (up to 50 cm -1 ) around 640 nm in thermally evaporated non-doped films of 4-di(4'-tert-butylbiphenyl-4-yl)amino-4'-dicyanovinylbenzene, which makes this material suitable for green-light pumped single-mode organic lasers with low threshold and superior stability. Lasing effect is demonstrated in a Distributed Bragg Resonator configuration, as well as under the form of random lasing at high pump intensities.