Gain in a quantum wire laser of high uniformity
  A multi-quantum wire laser operating in the 1-D ground state has been achieved in a very high uniformity structure that shows free exciton emission with unprecedented narrow width and low lasing threshold. Under optical pumping the spontaneous emission evolves from a sharp free exciton peak to a red-shifted broad band. The lasing photon energy occurs about 5 meV below the free exciton. The observed shift excludes free excitons in lasing and our results show that Coulomb interactions in the 1-D electron-hole system shift the spontaneous emission and play significant roles in laser gain. 
Hidefumi Akiyama, Loren N. Pfeiffer, Masahiro Yoshita, Aron Pinczuk,   Peter B. Littlewood, Ken W. West, Manyalibo J. Matthe...