Communications

T-Rays Advance Toward Airport Screening

(Page 2 of 2)

  • Tuesday, February 20, 2007
  • By Neil Savage

Hu's lasers are a "key component" of a terahertz security device that Sandia National Laboratory is developing, says Sandia principal investigator Mike Wanke. The three-year project at the lab, now in its second year, aims to integrate a laser source and a detector into the same device. That eliminates complex optical setups and improves detector sensitivity by orders of magnitude, Wanke says. He envisions a module that can be used to make compact, commercially viable t-ray systems for use in airports. "We're trying to make this so it's a turnkey, drop-into-place system," he says. He adds that once Sandia has a successful prototype, businesses can tackle the challenge of product development.

The lasers need to reach lower frequencies to do a better job of penetrating material--the lower, the better, says Hu. But lower frequencies mean smaller quantum wells, which are harder to build accurately. Hu won't predict when commercial systems could be available.

But Xi-Cheng Zhang, director of Rensselaer Polytechnic Institute's Center for Terahertz Research says Hu "always breaks the record he sets for himself." Zhang says that either improvements in the engineering or use of different semiconductor materials is likely to make even better quantum cascade lasers. He expects that most of the problems will be solved in a year or two. One such problem is that the lasers operate at cryogenic temperatures and require bulky cooling equipment; Hu holds the record for highest operating temperature. After such problems are solved, market forces rather than technical issues will determine how long it takes for a commercial scanner to show up in an airport, Zhang says.

Hu says that the technology is of particular interest to, besides commercial air-travel applications, the military. "DARPA [the Defense Advanced Research Projects Agency] is very interested in this to identify suicide bombers," he says. T-rays aren't the only way to do this; other systems reaching market use radar and vision-processing software. (See "Walking like a Bomber.")

Zhang founded a company, Zomega Terahertz that makes a laptop-size T-ray detector that can be attached to a flying drone for remote detection of chemical and biological substances. While the trillionths of a watt produced by the infrared laser in the device is fine for spectroscopic analysis of air samples, it's not adequate for imaging, and the laser technology is unlikely to improve enough to be used in airport security, Zhang says. He believes that quantum cascade lasers are the future of T-ray detection systems: "They will be the final winner in the market."

Print

Related Articles

Drive-by Gun Scans Prompt Privacy Questions

Police hope terahertz-scanning devices can be more effective than patting people down, but civil rights groups are wary.

Are Security Scanners Safe?

Scientists want more scanner safety data before they can say yes.

Detecting Dirty Bombs from a Safe Distance

A modified NASA telescope could detect dangerous radioactive materials.

Close Comments

To comment, please sign in or register

Forgot my password

nekote

139 Comments

  • 1821 Days Ago
  • 02/20/2007

How about in prisons, first?

The big issue, as I have perceived it, is seeing the (nude) outline of the human anatomy.

How about trying these scanners out in (men's) prisons first, where such issues would be a lesser degree of concern, than necessary security?

Failure to detect "shanks" (home made stabbing / cutting weapons) truly have murderous results.

Detecting contraband would also be extremely valuable.

Reply

mkogrady

425 Comments

  • 1821 Days Ago
  • 02/20/2007

Re: How about in prisons, first?

You'll need two -

One "whole body" scanner - external model

One "inner body" scanner - with replacement doo-hicky's (emphasis on Doo!)

Reply

blunney

17 Comments

  • 1821 Days Ago
  • 02/20/2007

Lovely, just lovely...

I wonder if all the airlines female passengers know they may as well fly naked?  That should do wonders for airline balance sheets.

The TSA is watching you...

Reply

jsessex

14 Comments

  • 1821 Days Ago
  • 02/20/2007

Re: Lovely, just lovely...

The nudity need not be a big deal if it is handled properly.  First, provide a display showing that the T-video provides low resolution generic pictures  but shows weapons very well.  Since the cameras see through skin and hair and do not show color, they are far from titillating to the average person.  Screeners should be located in a separate location without any visual connection to the test site allowing the person on the screen to maintain anonymity.  No recording of the video feed would be allowed.  The viewers should be older women, a group not very prone to being titillated by what would very quickly become a fairly boring job.  I think this plan addresses the biggest objections to this type of technology’s implementation.

Reply

cyberpageman

53 Comments

  • 1820 Days Ago
  • 02/21/2007

Re: Lovely, just lovely...

There was a big brouhaha a few years back about video cameras being able to see through clothing.  Maybe they could, but only the "barest" outline.

When x-rays were first discovered, there was worry about them too.  I remember my physics professor quoting:

The Roentgen Rays, the Roentgen Rays,
What is this craze?
The town's ablaze
With the new phase
of X-Ray's ways.

I'm full of daze,
shock and amaze;
For nowadays
I hear they'll gaze
Thro' cloak and gown--and even stays,
Those naughty, naughty Roentgen Rays

No one worries about Superman's x-ray vision, so why worry about terahertz rays, which are a lot less clear?

Reply

abcarterjr

45 Comments

  • 1820 Days Ago
  • 02/21/2007

Prospecting w/T-Rays

Could the T- Ray detector  help
classify a mountain stream as a go-nogo carrier
of micron gold?

Reply

ggeek99

2 Comments

  • 1817 Days Ago
  • 02/24/2007

Why do we line up for shackles

As I read these applications of "new" technologies, I wonder where the social outrage lies? Why do we raise our wrists to be bound with these new shackles without first asking why?

Why should it be illegal for adults to eat/smoke/drink the compounds of their choosing in a free society? How can society/government maintain a list of approved and nonapproved foods  & drugs for adult members of that society?

Why can I not carry a weapon for my protection in a society where the police are armed to the gills and trigger happy and the crooks likewise?

There is no place where people respect each other more than the parking lot of a gunshop. No one cuts each other off, no one takes anothers parking space. Why? Because they know the other maybe packing heat. Perhaps we would all respect each other a little bit more if we knew we could all defend ourselves in the heat of argument, so why argue?

If army exists to keep the peace, then so must guns. So why the hurry to disarm the civilian populace and arm the police & military?

If we implement perfect screening technologies without understanding the implications for our political futures then we deserve the future we get, not matter how how fascist or tyrannical.

Reply

Advertisement

MAGAZINE

Can We Build Tomorrow's Breakthroughs?

Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.

Advertisement

Technology Review Lists

TR50

Our list of the 50 most innovative companies, including the following:

Suntech

Crowdcast

Serious Materials

Novartis

More

Advertisement

Facebook

Advertisement