In a bid to curb the challenges of detecting and making images from terahertz waves, researchers at MIT, the University of Minnesota, and Samsung have developed a new kind of camera, called a Terahertz camera, that can detect terahertz pulses rapidly, with high sensitivity and at room temperature and pressure. The research work was published today in the journal Nature Nanotechnology by MIT doctoral student Jiaojian Shi, professor of chemistry Keith Nelson, and 12 others.
The research team created two distinct devices that can work at room temperature: one makes use of the quantum dot’s capacity to transform terahertz pulses into visible light, enabling the device to produce images of materials; the other generates images revealing the polarization state of the terahertz waves.
The sensitivity and resolution of the detector were proved by the researchers by taking terahertz-illuminated photographs of some of the structures utilized in their devices, such as the nano-spaced gold lines and the ring-shaped slits used for the polarized detector.
The new low-cost Terahertz camera is made up of numerous layers and was created using industry-standard manufacturing processes similar to those for microchips. The substrate is covered with a layer of light-emitting quantum dot material, followed by a layer of gold nanoscale parallel lines divided by tiny slits, and finally, a CMOS chip utilized to create an image.
A polarimeter, which has a construction similar to that of the polarization detector, can detect the polarization of incoming beams by using ring-shaped nanoscale slits.
Nelson notes that the incredibly low energy of the photons in terahertz radiation makes them difficult to detect. As a result, he explains, “this technology transforms that small tiny photon energy into something observable that’s easy to detect with a standard camera.”
The device outperformed today’s big, expensive systems in the team’s experiments by being able to detect terahertz pulses at low-intensity levels.
According to Sang-Hyun Oh, a co-author of the study and McKnight Professor of Electrical and Computer Engineering at the University of Minnesota, this system represents “a big step forward toward building a practical terahertz camera” despite the fact that current terahertz cameras cost tens of thousands of dollars. Samsung, a manufacturer of CMOS camera chips and quantum dot devices, joined this study because of the potential for commercialization.
In all, Nelson asserts that the new technology has the potential to be commercialized because quantum dots are currently accessible, affordable, and employed in consumer goods like television displays. He claims that although the actual manufacturing of the camera devices is more difficult, it also relies on current microelectronics technology.
Since the full terahertz camera chip can be produced using current conventional microchip production processes, unlike existing terahertz detectors, mass production of the devices should be feasible and reasonably priced.
