Linewidth and tuning characteristics of terahertz quantum cascade lasers.
We have measured the spectral linewidths of three continuous-wave quantum cascade lasers operating at terahertz frequencies by heterodyning the free-running quantum cascade laser with two far-infrared gas lasers. Beat notes are detected with a GaAs diode mixer and a microwave spectrum analyzer, permitting very precise frequency measurements and giving instantaneous linewidths of less than -30 kHz. Characteristics are also reported for frequency tuning as the injection current is varied.
Barkan
A
A
Department of Electrical and Computer Engineering, MS-366, Rice University, Houston, Texas 77251-1892, USA.
Tittel
F K
FK
Mittleman
D M
DM
Dengler
R
R
Siegel
P H
PH
Scalari
G
G
Ajili
L
L
Faist
J
J
Beere
H E
HE
Linfield
E H
EH
Davies
A G
AG
Ritchie
D A
DA