Improved performance of perylenediimide-based lasers
The aim of this work was to improve the laser performance, in terms of threshold and operational lifetime, of lasers based on polymer films doped with perylenediimide (PDI) derivatives as active media.
For such purpose, we first investigated the amplified spontaneous emission (ASE) properties of perylene orange (PDI-O), when doped into polystyrene (PS) films. Lower ASE thresholds and larger photostabilities than those of similar films containing another PDI derivative (PDI-C6), recently reported in the literature, have been measured. Results have been interpreted in terms of the photoluminescence efficiency of the films, which depends on the type of molecular arrangement, inferred with the help of nuclear magnetic resonance experiments. We also show that PS films have a better ASE performance, i.e. lower thresholds and larger photostabilities, than those based on poly(methyl methacrylate), which was recently highlighted as one of the best matrixes for PDI-O. Finally, a one-dimensional second-order distributed feedback laser using PS doped with PDI-O was fabricated and characterized. This device has shown a threshold significantly lower (by around one order of magnitude) than that of a similar laser based on PDI-C6-doped PS.