Laser operation in nondoped thin films made of a small-molecule organic red-emitter

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 nondoped 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.