Year-end Sale % OFF 
Abstract
Time-resolved mid-infrared pump-probe measurements are performed on a quantum cascade laser below and above the threshold. The gain recovery is determined by the electron transport through the cascade heterostructure. Subpicosecond resonant tunneling injection from the injector ground state into the upper lasing state is found to be incoherent due to the strong dephasing in the active subband. The gain recovery due to transport through superlattice is interpreted in terms of dielectric relaxation within the superlattice miniband.
Highlights
“Femtosecond Dynamics of Resonant Tunneling and Superlattice Relaxation in Quantum Cascade Lasers.” Applied Physics Letters 92 (12): 122114
In a quantum cascade laserQCL, a complex heterostructure controls the tunneling and superlattice relaxation of electrons as they move through the device, enabling a population inversion to be obtained in a unipolar device
One recent study reported coherent oscillations attributed to resonant tunneling in a QC heterostructure for electron densities of up to several 1011 cm−2.5 The structure used in that experiment, was not an operating laser, and so does not directly apply to the dynamics under working conditions; to date, most information on the transport and relaxation in QCLs has been obtained indirectly through steady-state measurements
Summary
“Femtosecond Dynamics of Resonant Tunneling and Superlattice Relaxation in Quantum Cascade Lasers.” Applied Physics Letters 92 (12): 122114. Norris,1 Tobias Gresch,2 Marcella Giovannini,2 Jérôme Faist,2 Laurent Diehl,3 and Federico Capasso3 1Center for Ultrafast Optical Science and Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA 2Institute of Physics, University of Neuchâtel, CH-2000 Neuchâtel, Switzerland 3School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USAReceived 29 October 2007; accepted February 2008; published online March 2008͒
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
