Abstract
Photocurrent correlation measurements used for the characterization of ultrafast photoconductive
switches based on GaAs and silicon-on-sapphire are demonstrated. The correlation signal arises
from the interplay of the photoexcited carriers, the dynamics of the bias field and a subsequent
recharging of the switch. By using both photocurrent measurements and terahertz spectroscopy we
verify the importance of space-charge effects on the carrier dynamics. Photocurrent nonlinearities
and coherent effects are discussed as they appear in the correlation signals. An analysis based on a
simple model allows an estimate of the carrier lifetimes associated with the photoconductive
switching process. We illustrate how pulse propagation can be studied sequentially using this
technique and how a minor modification of the experimental setup enables the study of screening
from long-lived carriers. We emphasize in what ways the different techniques of measuring
ultrashort electrical pulses are sensitive to different aspects of the pulse forming mechanisms.
Original language | English |
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Journal | Journal of Applied Physics |
Volume | 79 |
Issue number | 5 |
Pages (from-to) | 2649-2657 |
Number of pages | 9 |
ISSN | 0021-8979 |
DOIs | |
Publication status | Published - 1 Mar 1996 |
Keywords
- CARRIER LIFETIMES
- TRANSMISSION-LINES
- DAMAGED GAAS
- RADIATION
- DYNAMICS
- SILICON
- SPECTROSCOPY
- PHOTODIODES
- GENERATION
- INSULATORS