Laser emission in periodically modulated polymer films

We report on the realization of a compact distributed feedback laser using luminescent polymer films where the optical feedback is provided by Bragg d iffraction on an index grating. Permanent modulation of the polymer refract ive index is achieved using an original technique for photoinduced patterni ng of surface relief grating, using laser-controlled mass-transport in azoa romatic polymers. We describe the fabrication of such surface gratings and show the laser emission properties resulting from a transversal one-photon pumping of the sinusoidally modulated polymer films upcovered with a lumine scent-dye-doped film. Control of the laser wavelength by the grating pitch is evidenced. (C) 2001 American Institute of Physics.