Optically pumped blue organic semiconductor lasers

Lasing at 460, 485, and 510 nm is demonstrated in optically pumped, vacuum-deposited amorphous thin films of a carbazole derivative doped with Coumarin 47, perylene, and Coumarin 30, respectively. Efficient, nonradiative Förster energy transfer between host and dopant organic molecules results in low lasing thresholds $\text{(5\hspace{0.5em}}{\mathrm{\mu J/cm}}^{\mathrm{2}}\mathrm{),}$ high differential quantum efficiencies (15%), high peak output powers (20 W), and long operational lifetimes ${\text{(>10}}^5$ pulses at 100 times the threshold power).