Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rice engineers demo first T-ray endoscope

18.11.2004


Technology could aid explosive detection, cancer screening, more



Electrical engineers at Rice University in Houston have demonstrated the world’s first endoscope for terahertz imaging, a discovery that could extend the reach of terahertz-based sensors for applications as wide-ranging as explosives detection, cancer screening and industrial and post-production quality control.

The research appears in the Nov. 18 issue of the journal Nature. It presents the emerging terahertz sensing industry with a unique new technology for transporting terahertz waves from a source and directing them at a particular target of interest. "Our wave guide opens up a whole new class of capabilities because it offers a way to get terahertz energy into places it could never reach before," said lead researcher Daniel Mittleman, associate professor of electrical and computer engineering. "Wave guide technology frees you to look around corners and get into tight places."


Terahertz waves, also known as T-waves or T-rays, fall between microwaves and infrared light in the least-explored region of the electromagnetic spectrum. Metals and other electrical conductors are opaque to T-rays, but they can penetrate plastic, vinyl, paper, dry timber and glass like X-rays. Unlike X-rays, T-rays are not hazardous radiation, and in some cases T-wave sensors can reveal not only the shape of a hidden object but also its chemical composition. This unique combination of traits make T-waves perfect for applications like explosive detection, and several companies are already working on T-wave security applications, developing systems that can look inside people’s shoes, bags and clothing for guns, bombs and contraband.

T-rays lie between microwaves, whose wavelengths measure from centimeters to millimeters, and light, with wavelengths measured in nanometers, or billionths of a meter. The gap between -- the so-called terahertz gap -- contains wavelengths from 30 to 3000 microns, or 100 GHz to 10 THz when measured in frequency. The terahertz gap has been called the "final frontier" of the electromagnetic spectrum because there’s never been an easy or cheap way to either generate or measure T-rays, something that’s only begun to change with the advent of new technology in the past decade.

The development of "wave guides" is a key element in the technical maturation of T-ray technology. Wave guides -- like fiber optic cables for lasers and coaxial cables for microwaves -- allow design flexibility because they move and direct energy where it’s needed. This is particularly useful if the beam generator is bulky or temperamental. Both fiber optic cables and coaxial cables work by confining the energy of the beam in a small space, causing it to propagate down the cable.

Coaxial cables aren’t good guides for T-waves because the metal sheath absorbs T-wave energy very quickly, and fiber optics don’t transmit T-waves. By blending some aspects of both these technologies, Mittleman’s team devised a system to guide T-waves in and out of a confined space. This could prove useful for sensing applications that range from the mundane -- scanning packages of cookies or cereal to make sure fruit and nuts are distributed evenly in every carton -- to the space age -- checking for defects under the insulation and heat shield of NASA’s space shuttle.

In all T-wave applications today, the beam must be aimed directly from the wave generator at the spot to be sensed. Anything that needs to be scanned has to be moved in front of the beam. Moving the beam isn’t practical because the beam has to be fine-tuned each time it’s set up, and worse, the whole apparatus is very sensitive to bumps and vibrations, which can easily knock the beam out of alignment.

Mittleman and his student, Kanglin Wang, stumbled upon the idea for the wave guide when they noticed T-waves were moving down a wire during an experiment on a new form of terahertz microscopy. In follow-up experiments, they found they could move T-waves along a bare wire, direct those waves onto a surface, catch the reflected waves on another wire, carry those reflected waves back to a receiver and analyze the return waves to reveal information about the surface the original wave was shined upon.

"There are lots of places where T-waves would be handy but where they’re difficult to use today," said Mittleman. "Free-space beams are notoriously temperamental -- a shortcoming that’s kept them off of some factory floors -- and our endoscope technology has the potential to change that."

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Power and Electrical Engineering:

nachricht Improved stability of plastic light-emitting diodes
19.04.2018 | Max-Planck-Institut für Polymerforschung

nachricht Intelligent components for the power grid of the future
18.04.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>