Featured Research

from universities, journals, and other organizations

Tiny Infrared Laser Holds Promise As Weapon Against Terror

Date:
August 14, 2005
Source:
Northwestern University
Summary:
Northwestern University researchers have demonstrated a specialized laser that holds promise as a weapon of defense in civilian and military applications. They became the first to create a quantum cascade laser that can operate continuously at high power and at room temperature with an emission wavelength of 9.5 microns and a light output greater than 100 milliwatts. Once optimized, the tiny laser could be used for the early detection of explosives and chemical warfare agents.

EVANSTON, Ill. --- The difficulty of detecting the presence of explosives and chemical warfare agents (CWAs) is once again all too apparent in the news about the London bombings.

In a significant breakthrough, researchers at Northwestern University's Center for Quantum Devices have demonstrated a specialized diode laser that holds promise as a weapon of defense in both civilian and military applications. Once optimized, the tiny laser could quickly detect explosives and CWAs early and warn against possible threats.

The Northwestern team, led by center director Manijeh Razeghi, became the first to create a quantum cascade laser (QCL) that can operate continuously at high power and at room temperature with an emission wavelength of 9.5 microns and a light output of greater than 100 milliwatts.

Existing standard diode lasers, such as those used to read compact discs or barcodes, do not operate effectively in the longer wavelengths that are required to detect CWAs. The challenge for researchers around the world has been to develop a portable laser that operates in the far-infrared (wavelengths of 8 to 12 microns). Every chemical has a unique "fingerprint" because it absorbs light of a specific frequency, and most CWAs fall in the 8 to 12 micron region.

"Our achievement is critical to building an extremely sensitive chemical detection system," said Razeghi, Walter P. Murphy Professor of Electrical and Computer Engineering. "One of the key elements in a successful system is the laser source. Both mid- and far-infrared diode lasers need to operate at room temperature, have high power -- greater than 100 milliwatts -- and be extremely small in order to keep the system portable. We have now demonstrated such a laser in the far-infrared wavelength range."

This research is part of a four-year program called Laser Photoacoustic Spectroscopy (LPAS) funded by the Defense Advanced Research Projects Agency (DARPA). The goal of the program is to develop a man-portable system that can warn against a large number of potential threats using mid- and far-infrared diode lasers. Once optimized, such lasers would be a very reliable means of detecting explosives and chemical warfare agents while distinguishing them from benign chemicals present in the atmosphere.

During the next two years Razeghi and her team will work to put together a detection system based on the center's far-infrared laser. The system will then be evaluated by DARPA for use by the military.

Northwestern is a world leader in high-power QCL research. The Center for Quantum Devices was the first university research lab in the world to successfully grow, fabricate and test quantum cascade lasers back in 1997. By utilizing quantum mechanical design principles and advanced crystal growth techniques, the QCL is able to demonstrate high-power and high-temperature operation.

After the initial demonstration of room-temperature pulsed lasers in 1997, the primary efforts of Razeghi and her colleagues over the past several years have been to increase the laser's operating temperature, power output and efficiency in order to achieve the continuous operation necessary for sensitive chemical analysis.

In 2003 the center was the first to demonstrate high-power mid-wavelength infrared continuous wave QCLs operating above room temperature. (Like the far infrared, standard diode lasers cannot access this mid-infrared range.) At present, individual devices with output powers of several hundred milliwatts have been demonstrated in the 3 to 5 microns wavelength range.

###

Razeghi's research is supported by the Defense Advanced Research Projects Agency, U.S. Air Force Office of Scientific Research, the Army Research Office and the Office of Naval Research.


Story Source:

The above story is based on materials provided by Northwestern University. Note: Materials may be edited for content and length.


Cite This Page:

Northwestern University. "Tiny Infrared Laser Holds Promise As Weapon Against Terror." ScienceDaily. ScienceDaily, 14 August 2005. <www.sciencedaily.com/releases/2005/08/050805180129.htm>.
Northwestern University. (2005, August 14). Tiny Infrared Laser Holds Promise As Weapon Against Terror. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2005/08/050805180129.htm
Northwestern University. "Tiny Infrared Laser Holds Promise As Weapon Against Terror." ScienceDaily. www.sciencedaily.com/releases/2005/08/050805180129.htm (accessed April 19, 2014).

Share This



More Matter & Energy News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins