  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.
