Intersubband Raman laser

An intersubband Raman laser has been realized in an artificial GaAs/AlGaAs three-level quantum-well structure. A CO2 laser in resonance with the one-t o-three level transition is used as the pump, while the lasing emission occ urs via the three-to-two level transition. The one-to-two level spacing is designed to be in resonance with the AlAs-like longitudinal optical phonon mode, favoring the Raman process. This work presents an alternative mechani sm for realizing intersubband lasers and opens up new possibilities in reac hing the far infrared region and achieving room-temperature operation. (C) 2001 American Institute of Physics.