Picometrix a subsidiary of Advanced Photonix (API) eyes T-ray technology for next-generation sensors

my note: this article came in yesterday May 27th, 2010 via google alerts for picometrix.
http://tinyurl.com/33gqk9b

Please note it could be a dated story, as there is nothing which identifies when it was first released. I thought there was some interesting information contained in it, which I had never heard before, or perhaps had forgotten.



ANN ARBOR, Mich. — Optoelectronics designers at Picometrix Inc. in Ann Arbor, Mich., are working on a new kind of sensor for military and homeland-security applications that is able to see through a wide variety of solid materials.

The sensor, which uses rays in the terahertz region of the electromagnetic spectrum, is under consideration for applications ranging from airport baggage inspection, quality control for spacecraft and rockets, and for standoff explosives detection.

Picometrix leaders call the terahertz energy that these sensors use "T-rays," says Robin Risser, chief executive officer of Picometrix. T-rays represent the portion of the electromagnetic spectrum between infrared waves and x-rays, or between about 100 GHz and 30 THz. Energy from T-rays are not harmful to humans, require no shielding, and are small and light enough to lend themselves to mobile applications.

Among the most significant enabling technologies for deployable T-ray sensors are ultrafast lasers, oscillators, quantum-cascade lasers, and heterojunction diode and transistor circuits.

One of the biggest advantages of T-rays for security applications is the technology's ability to detect not only objects that may be explosives, but also the chemical composition of these objects. This way, security officials could determine whether the objects represent a threat, Risser says.

T-rays can detect objects and their chemical compositions concealed under cloth, leather, plastic, cardboard, and other common packaging materials. T-rays also can detect and determine the chemical composition of unknown gas clouds and airborne particles that may be biological warfare agents.

Picometrix was founded in 1992 as an outgrowth of the University of Michigan's Center for Ultrafast Optical Science in Ann Arbor, Mich., which had financial support from the National Science Foundation in Arlington, Va., Risser explains.

One of the company's first big breakthroughs came in 1997 when Picometrix started work on its QA-1000 quality-control program to inspect for manufacturing defects. Technology from this program eventually went to NASA to help experts inspect the space-shuttle fuel tanks for defects in the sprayed-on insulation.

Investigators blame a fuel-tank insulation defect for the February 2003 disaster that destroyed the Space Shuttle Columbia. Experts say a piece of insulation broke off during launch and damaged the shuttle's wing, which caused the spacecraft to disintegrate on reentry.

T-ray technology could help guard against such things in the future by scanning the shuttle's fuel tanks for any tears, delaminations, or other damage that could lead to chunks of insulation breaking off during launch, Risser says.

Today Picometrix is working with the U.S. Transportation Security Administration in Washington to develop a new generation of passenger baggage scanners. Company engineers are working on advanced research projects for new baggage scanners, and deployable technology should be ready for this application within the next two to three years, Risser says.

Tests of T-ray baggage-screening technology are tentatively scheduled at the Federal Aviation Administration Technical Center in Atlantic City, N.J., over the next one to two years.

The drawbacks to T-rays, Risser points out, involve its inability to see through metal and through significant amounts of water. When security experts need to see through metal and water, they must use different sensors, he says.

For the future, Picometrix experts are looking at T-rays as a way to screen objects from standoff distances of 30 to 40 feet for explosives, biological agents, or other threats.