The nature of the electron distribution and the electron-lattice energy relaxation phenomena in all classes of quantum cascade lasers operating in the THz range, namely, resonant-phonon, bound-to-continuum, and interlaced photon-phonon designs are reviewed. Thermalized hot-electron distributions are found in all cases. However, electronic temperatures of individual conduction subband are strongly influenced by the specific quantum design and the actual electron-lattice energy relaxation channels. A wealth of information was obtained both below and above laser threshold from the analysis of micro-probe band-to-band photoluminescence spectra recorded with a spatial resolution of approximate to 2 mu m. The influence of the detailed knowledge of the hot electron distributions on the design of improved THz quantum cascade lasers aiming at high temperature operation will be discussed.
|Titolo:||Experimental Investigation of Hot Carriers in Terahertz Quantum Cascade Lasers|
|Data di pubblicazione:||2008|
|Digital Object Identifier (DOI):||10.12693/APhysPolA.113.787|
|Appare nelle tipologie:||1.1 Articolo in rivista|