Surface plasmon quantum cascade lasers as terahertz local oscillators.
We characterize a heterodyne receiver based on a surface-plasmon waveguide quantum cascade laser (QCL) emitting at 2.84 THz as a local oscillator, and an NbN hot electron bolometer as a mixer. We find that the envelope of the far-field pattern of the QCL is diffraction-limited and superimposed onto interference fringes, which are similar to those found in narrow double-metal waveguide QCLs. Compared to the latter, a more directional beam allows for better coupling of the radiation power to the mixer. We obtain a receiver noise temperature of 1050 K when the mixer is at 2 K, which, to our knowledge, is the highest sensitivity reported at frequencies beyond 2.5 THz.
Hajenius
M
M
Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
Khosropanah
P
P
Hovenier
J N
JN
Gao
J R
JR
Klapwijk
T M
TM
Barbieri
S
S
Dhillon
S
S
Filloux
P
P
Sirtori
C
C
Ritchie
D A
DA
Beere
H E
HE