Excitation-density-dependent generation of broadband terahertz radiation in an asymmetrically excited photoconductive antenna.
The generation of terahertz (THz) transients in photoconductive emitters has been studied by varying the spatial extent and density of the optically excited photocarriers in asymmetrically excited, biased low-temperature-grown GaAs antenna structures. We find a pronounced dependence of the THz pulse intensity and broadband (>6.0 THz) spectral distribution on the pump excitation density and simulate this with a three-dimensional carrier dynamics model. We attribute the observed variation in THz emission to changes in the strength of the screening field.
Upadhya
Prashanth C
PC
School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK. p.upadhya@leeds.ac.uk
Fan
Wenhui
W
Burnett
Andrew
A
Cunningham
John
J
Davies
A Giles
AG
Linfield
Edmund H
EH
Lloyd-Hughes
James
J
Castro-Camus
Enrique
E
Johnston
Michael B
MB
Beere
Harvey
H