Inkjet-printed vertically emitting solid-state organic lasers
  In this paper, we show that Inkjet Printing can be successfully applied to external-cavity vertically-emitting thin-film organic lasers, and can be used to generate a diffraction-limited output beam with an output energy as high as 33.6 uJ with a slope efficiency S of 34%. Laser emission shows to be continuously tunable from 570 to 670 nm using an intracavity polymer-based Fabry-Perot etalon. High-optical quality films with several um thicknesses are realized thanks to ink-jet printing. We introduce a new optical material where EMD6415 commercial ink constitutes the optical host matrix and exhibits a refractive index of 1.5 and an absorption coefficient of 0.66 cm-1 at 550-680 nm. Standard laser dyes like Pyromethene 597 and Rhodamine 640 are incorporated in solution to the EMD6415 ink. Such large size " printed pixels " of 50 mm 2 present uniform and flat surfaces, with roughness measured as low as 1.5 nm in different locations of a 50um x 50um AFM scan. Finally, as the gain capsules fabricated by Inkjet printing are simple and do not incorporate any tuning or cavity element, they are simple to make, have a negligible fabrication cost and can be used as fully disposable items. This works opens the way towards the fabrication of really low-cost tunable visible lasers with an affordable technology that has the potential to be widely disseminated. 
Oussama Mhibik (LPL), S\'ebastien Ch\'enais (LPL), S\'ebastien Forget   (LPL), Christophe Defranoux, S\'ebastien Sanaur (BEL...
physics.optics