Low-threshold blue-emitting monolithic polymer vertical cavity surface-emitting lasers

The authors report on a monolithic vertical microcavity blue laser with a carbazole/fluorenyl derivative copolymer active film. The laser is realized by electron-beam deposition of the two dielectric mirrors on the bottom and on the top of the polymeric active layer. The devices exhibit a threshold fluence as low as 1.2 mu J/cm(2), with a divergence of the emission beam of 2.8 degrees. The measured lasing threshold and operational lifetimes (> 1.5x10(4) pulses at an excitation density 500 times larger than threshold) are among the best so far reported for blue-emitting polymer lasers, thus making these devices promising candidates for future electrical excitation. (c) 2006 American Institute of Physics.