DocumentCode :
831634
Title :
Transient carrier and field dynamics in quantum-well parallel transport: From the ballistic to the quasi-equilibrium regime
Author :
Sha, Weijan ; Rhee, June-Koo ; Norris, Theodore B. ; Schaff, William J.
Author_Institution :
Center for Ultrafast Opt. Sci., Michigan Univ., Ann Arbor, MI, USA
Volume :
28
Issue :
10
fYear :
1992
fDate :
10/1/1992 12:00:00 AM
Firstpage :
2445
Lastpage :
2455
Abstract :
Femtosecond optical techniques have been used to probe transient electron transport and electric field dynamics in high field parallel transport, in a horizontal p-i-n quantum-well structure. Physical quantities associated with transport transients, such as electron distribution functions, electron velocity, and electron acceleration, have been measured by means of femtosecond absorption saturation, excitonic electroabsorption, and terahertz electromagnetic radiation, at electric fields of up to 16 kV/cm. Important transport phenomena, such as ballistic acceleration on a time scale of 150 fs and the onset of a saturated velocity on a time scale of 1 ps, have been observed in the experiments. The time-dependent electric field has also been measured. It is found that both space-charge screening and terahertz radiation contribute to the collapse of the applied electric field at high carrier densities. Under such circumstances, transport and electric field dynamics are strongly coupled. An energy overshoot due to the field collapse coupled with strong electron-LO phonon scattering on a time scale of 200 fs is demonstrated
Keywords :
carrier density; electroabsorption; electron-phonon interactions; high field effects; optical saturable absorption; semiconductor quantum wells; 1 ps; 150 fs; 200 fs; ballistic acceleration; electric field dynamics; electron acceleration; electron distribution functions; electron velocity; energy overshoot; excitonic electroabsorption; femtosecond absorption saturation; femtosecond optical techniques; field collapse; high carrier densities; high field parallel transport; horizontal p-i-n quantum-well structure; physical quantities; quasi-equilibrium regime; saturated velocity; space-charge screening; strong electron-LO phonon scattering; terahertz electromagnetic radiation; time-dependent electric field; transient electron transport; transport transients; Acceleration; Electric variables measurement; Electromagnetic transients; Electron optics; Optical saturation; Optical scattering; PIN photodiodes; Probes; Quantum wells; Ultrafast optics;
fLanguage :
English
Journal_Title :
Quantum Electronics, IEEE Journal of
Publisher :
ieee
ISSN :
0018-9197
Type :
jour
DOI :
10.1109/3.159551
Filename :
159551
Link To Document :
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