Lineshape in Quantum Cascade Lasers--Temperature, Screening and Broadening
Friday, December 4, 2009, 14:00
Lecture Hall B, Sölvegatan 14
The Quantum Cascade Laser (QCL) is a semiconductor diode laser operating
in the infra-red and THz region and was first realized at Bell Labs in
1994 . The operating principle of QCLs differs fundamentally from
standard diode lasers as light emission occurs from transitions between
electronic states in quantum wells formed in the conduction band of laser
This thesis investigate the microscopic mechanisms determining the spectra
of the lasing material. Focus is put on the mechanisms that reduce peak
gain with temperature. The main finding is that the electronic temperature
strongly affect scattering strengths via screening which then is reflected
in increased spectral broadening.
 Faist, J., Capasso, F., et. al., Science, 1994, 264, 553.