High-power GaAs/AlGaAs quantum fountain unipolar laser emitting at 14.5 mum with 2.5% tunability

We demonstrate operation of a high-power quantum fountain unipolar laser re lying on intersubband emission in optically pumped GaAs/AlGaAs quantum well s. The collected power per facet is as large as 2.3 W at 20 K and 1.5 W at 120 K, which translates into 6.6 W optical power per facet at low temperatu re accounting for collection efficiency. The maximum operating temperature is 135 K. We also demonstrate that the lasing wavelength can be tuned by as much as Delta lambda/lambda approximate to 2.5% simply by tuning the pump wavelength. (C) 1999 American Institute of Physics. [S0003-6951(99)03511-1] .