Deep Blue Laser Gain Medium Based on Triphenylamine Substituted Arylfluorene With Improved Photo-Stability

We report a novel blue emission triphenylamine substituted arylfluorene (SPhTPA) as organic optical gain medium with low amplified spontaneous emission (ASE) threshold. The optical gain related properties of SPhTPA and its blends with inert polymer, polystyrene (PS), were investigated in detail. This study shows the gain property and photo-stability of SPhTPA have been improved significantly by doping it into PS. The lowest ASE threshold was obtained for the SPhTPA/PS film doped with 20 wt.% SPhTPA. The film of the same doping ratio exhibited high net gain coefficient (27.8 cm
⁻¹
) and low loss coefficient (7.2 cm
⁻¹
). Moreover, the blend film demonstrated a significantly improved photo-stability. The ASE photo-stability half-life of the blend film was 15 fold higher than the pristine SPhTPA film when pumped in open ambient atmosphere. This paper suggests that this triphenylamine substituted arylfluorene is a highly prospective gain medium and doping it into PS is an efficient approach for developing air-stable SPhTPA-based organic lasers.