Terahertz inverse synthetic aperture radar (ISAR) imaging with a quantum cascade laser transmitter.
A coherent transceiver using a THz quantum cascade (TQCL) laser as the transmitter and an optically pumped molecular laser as the local oscillator has been used, with a pair of Schottky diode mixers in the receiver and reference channels, to acquire high-resolution images of fully illuminated targets, including scale models and concealed objects. Phase stability of the received signal, sufficient to allow coherent image processing of the rotating target (in azimuth and elevation), was obtained by frequency-locking the TQCL to the free-running, highly stable optically pumped molecular laser. While the range to the target was limited by the available TQCL power (several hundred microwatts) and reasonably strong indoor atmospheric attenuation at 2.408 THz, the coherence length of the TQCL transmitter will allow coherent imaging over distances up to several hundred meters. Image data obtained with the system is presented.
Danylov
Andriy A
AA
Submillimeter-Wave Technology Laboratory, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA. Andriy_Danylov@student.uml.edu
Goyette
Thomas M
TM
Waldman
Jerry
J
Coulombe
Michael J
MJ
Gatesman
Andrew J
AJ
Giles
Robert H
RH
Qian
Xifeng
X
Chandrayan
Neelima
N
Vangala
Shivashankar
S
Termkoa
Krongtip
K
Goodhue
William D
WD
Nixon
William E
WE