Terahertz (THz) radiation, or far-infrared light, is potentially very useful for security applications, as it can penetrate clothing and other materials to provide images of concealed weapons, drugs, or other objects. However, THz scanners must usually be very close to the objects they are imaging. Doubts have lingered over whether it is possible to use THz waves to image objects that are far away, because water vapor in air absorbs THz radiation so strongly that most of it never reaches the object to be imaged.
At the upcoming CLEO/QELS meeting in Baltimore, an MIT-Sandia team will demonstrate the first real-time THz imaging system that obtains images from 25 meters away. The technique takes advantage of the fact that there are a few "windows," or frequency ranges, of the terahertz spectrum that do not absorb water very strongly. The MIT-Sandia group designed a special, semiconductor-based device known as a "quantum cascade laser" that delivers light in one of these windows (specifically, around 4.9 THz). They shine this light through a thin target with low water content (for example, a dried seed pod), and a detector on the other side of the sample records an image.
A cryorefrigerator maintains the laser at a temperature of 30 Kelvin, where it produces 17 milliwatts of power (as opposed to the microwatts of power typical of pulsed terahertz sources) in order to provide enough terahertz radiation to obtain a decent image. Increasing the power of the lasers and sensitivity of the detectors can potentially enable imaging of thicker objects or imaging of the reflected light, which would be more practical for security applications. In addition, the development of high-operating-temperature quantum cascade lasers, which operate without the use of cryogenic materials, may also increase the availability of this approach. In the closer term, however, this approach may enable sensing of chemical residues or contaminants in the air.
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Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
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