Phase locking of a 2.7 THz quantum cascade laser to a microwave reference.
We demonstrate the phase locking of a 2.7 THz metal-metal waveguide quantum cascade laser (QCL) to an external microwave signal. The reference is the 15th harmonic, generated by a semiconductor superlattice nonlinear device, of a signal at 182 GHz, which itself is generated by a multiplier chain (x12) from a microwave synthesizer at approximately 15 GHz. Both laser and reference radiations are coupled into a bolometer mixer, resulting in a beat signal, which is fed into a phase-lock loop. The spectral analysis of the beat signal confirms that the QCL is phase locked. This result opens the possibility to extend heterodyne interferometers into the far-infrared range.
SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands.
P
P
Khosropanah
A
A
Baryshev
W
W
Zhang
W
W
Jellema
J N
JN
Hovenier
J R
JR
Gao
T M
TM
Klapwijk
D G
DG
Paveliev
B S
BS
Williams
S
S
Kumar
Q
Q
Hu
J L
JL
Reno
B
B
Klein
J L
JL
Hesler