Imaging of 3.4 THz quantum cascade laser beam using uncooled microbolometer camera

Abstract

The employment of terahertz (THz) technology for applications including Improvised Explosive Device (IED) and concealed weapons detection is a rapidly growing field of research. Additionally, THz waves do not pose a health hazard as do x-rays and as such can be used for the imaging and detection of certain cancers. To date, however, most detectors are highly sophisticated, bulky systems which require extensive cooling in order to provide a signal-tonoise (SNR) ratio high enough for detection. A detection system that is simple in operation and uncooled is highly desirable and is the focus of this research. In this thesis, operation of a 3.4 THz quantum cascade laser (QCL) was successfully achieved using a closed cycle cryostat and nanosecond pulse generator with impedance matching circuitry. The laser beam was imaged in real time using an uncooled microbolometer infrared camera typically used in far-infrared wavelength band (8-12 mm). The preliminary findings offer potential for development of a compact THz imaging system for applications involving concealed object detection.