Novel Concepts for Organic Lasers

Abstract

AbstractIn this chapter, we attempt to analyze some novel research tracks in the field of organic lasers. The quest of the “organic laser diode”, or electrically-pumped organic semiconductor laser, is not properly speaking a novel research axis as it has been driving the scientific community since almost the beginning of the story of OSC development. However it remains unrealized at the time of writing this book, and it is still a major scientific challenge. Many works have contributed to a better understanding of the bottlenecks preventing electrical pumping of organic lasers, they are briefly reviewed here. In the meantime, new and alternative concepts came to birth. Optically-pumped organic lasers ceased to be regarded as intermediate steps leading to a future electrically-pumped device; instead they started to be regarded as interesting devices on their own, as far as cheap pump sources, such as laser diodes or even light-emitting diodes, could be used. A fundamental challenge which remains to be solved is the realization of a true CW laser with an organic solid-state medium. By “true CW” it is meant that the laser medium is not physically moving to mimic dye circulation. Triplets are central in this problem and they have to be “managed” in some way; some interesting solutions have been proposed which are also briefly reviewed. Finally, Interesting new research fields have recently emerged using organic gain media in devices that are not classical lasers anymore, but rather devices based on quasiparticles such as exciton-polaritons (mixing of photon states and excitons) or Surface Plasmons (and Surface Plasmon Polaritons). The latter are called spasers, not all of them are organic but these devices can clearly beneficiate from the high gain provided by organic materials; they offer great promises in the realization of sub-wavelength coherent sources. KeywordsLight Emit DiodeGain MediumEquivalent OLEDsTriplet ExcitonSinglet ExcitonThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.