Communication: Polarized light sources based on stretch-oriented conjugated polymers are reported. The devices, based on poly(3-(4-octylphenyl)-2,2'-bithiophene, show an external quantum efficiency of 0.1% and are produced using a very simple method which may be easily extended to other polymers. The fabrication of the devices is described and factors such as the emission and spectral differences parallel and perpendicular to the stretching direction discussed.