Title :
Dual-frequency imaging using an electrically tunable terahertz quantum cascade laser
Author :
Dean, Paul ; Saat, N.K. ; Khanna, Suraj P. ; Salih, Mohammed ; Burnett, Andrew ; Cunningham, John ; Linfield, Edmund H. ; Davies, A. Giles
Author_Institution :
Sch. of Electron. & Electr. Eng., Univ. of Leeds, Leeds, UK
Abstract :
We report dual-frequency imaging using an electrically tunable terahertz frequency quantum cascade laser (QCL). Images of powdered materials including the explosive pentaerythritol tetranitrate (PETN) were acquired at 3.05 THz and 3.24 THz in a single scan. We show that it is possible to distinguish PETN from other materials by taking the difference-transmission and difference-attenuation images. We also demonstrate difference-intensity imaging by combining amplitude modulation of the QCL bias with lock-in detection.
Keywords :
amplitude modulation; explosives; laser beam applications; laser tuning; optical modulation; organic compounds; powders; quantum cascade lasers; terahertz wave imaging; PETN; amplitude modulation; difference-attenuation images; difference-intensity imaging; difference-transmission images; dual-frequency imaging; electrically tunable terahertz laser; explosive; frequency 3.05 THz; frequency 3.24 THz; lock-in detection; pentaerythritol tetranitrate; powdered materials; quantum cascade laser; Optical imaging; Quantum cascade lasers; Tunable circuits and devices;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves, 2009. IRMMW-THz 2009. 34th International Conference on
Conference_Location :
Busan
Print_ISBN :
978-1-4244-5416-7
Electronic_ISBN :
978-1-4244-5417-4
DOI :
10.1109/ICIMW.2009.5325590
