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Carrier relaxation dynamics in an ultrafast all-optical modulator using an intersubband transition.
- Source :
-
Applied Physics Letters . 12/31/2001, Vol. 79 Issue 27, p4509. 3p. 2 Diagrams, 1 Graph. - Publication Year :
- 2001
-
Abstract
- An improvement of an all-optical modulation scheme that utilizes an intersubband transition is proposed and investigated in connection with intersubband carrier relaxation dynamics. N-doped GaAs/AlGaAs quantum wells are pumped by an ultrashort (∼120 fs) intersubband-resonant pulse and probed by an interband-resonant white-light continuum. Ultrafast modulation speed of ∼0.4 ps is demonstrated, which is faster than that of the previous scheme by as much as a factor of 10. It is found that a large part of the carriers, which are excited from the first conduction subband to the second conduction subband, transfer to unknown trapping states at a relaxation time that is comparable to that of the pump–pulse duration. The existence of the carrier relaxation path via L valley subbands is strongly suggested as the cause. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Subjects :
- *CARRIER control systems
*OPTICAL communications
Subjects
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 79
- Issue :
- 27
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 5742100
- Full Text :
- https://doi.org/10.1063/1.1427154