The universe is awash in terahertz (THz) waves, as harmless as they are abundant. But unlike other regions of the electromagnetic spectrum, THz has proven to be extremely difficult to manipulate in order to capture novel images of objects and materials with which these light waves interact.
Most existing THz imaging devices employ prohibitively expensive technology or require several hours and cumbersome manual controls in order to generate a viable image, according to Boston College Professor of Physics Willie J. Padilla.
Padilla and researchers in his lab recently reported a breakthrough in efforts to create accessible and effective THz imaging. Using both optical and electronic controls, the team developed a single-pixel imaging technique that uses a coded aperture to quickly and efficiently manipulate stubborn THz waves, according to a recent report in the journal Optics Express.
In the so-called terahertz gap, a region of wavelengths that falls between microwave and infrared frequencies, conventional electronic sensors and semiconductor devicesare ineffective. Some systems capture only a fraction of a scene and the means to tune these THz waves are inefficient. This has fueled the search for new imaging technologies in order to manipulate THz waves.
Efforts to overcome the challenges of mechanics, cost and image clarity are viewed as a crucial step in efforts to tame the THz gap since imaging and sensing at this frequency holds the potential for advances in areas as divergent as chemical fingerprinting, security imaging of hidden weapons, even real-time skin imaging to promote simple detection of skin cancer.
Read more at: Phys.org