Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Space Industry and Business News .




TECH SPACE
Northwestern Researchers Develop Compact, High-Power Terahertz Source at Room Temperature
by Staff Writers
Chicago IL (SPX) Oct 10, 2013


Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science at Northwestern University's McCormick School of Engineering and Applied Science.

Terahertz (THz) radiation - radiation in the wavelength range of 30 to 300 microns - is gaining attention due to its applications in security screening, medical and industrial imaging, agricultural inspection, astronomical research, and other areas. Traditional methods of generating terahertz radiation, however, usually involve large and expensive instruments, some of which also require cryogenic cooling.

A compact terahertz source - similar to the laser diode found in a DVD player -operating at room temperature with high power has been a dream device in the terahertz community for decades.

Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science at Northwestern University's McCormick School of Engineering and Applied Science, and her group has brought this dream device closer to reality by developing a compact, room-temperature terahertz source with an output power of 215 microwatts.

Razeghi will present the research October 7 at the International Conference and Exhibition on Lasers, Optics and Photonics in San Antonio, and also at the European Cooperation in Science and Technology conference in Sheffield, England on October 10. The findings were published July 1 in the journal Applied Physics Letters and was presented at the SPIE Optics + Photonics conference in August in San Diego.

Razeghi's group is a world leader in developing quantum cascade lasers (QCL), compact semiconductor lasers typically emitting in the mid-infrared spectrum (wavelength range of 3 to 16 microns).

Terahertz radiation is generated through nonlinear mixing of two mid-infrared wavelengths at 9.3 microns and 10.4 microns inside a single quantum cascade laser.

By stacking two different QCL emitters in a single laser, the researchers created a monolithic nonlinear mixer to convert the mid-infrared signals into terahertz radiation, using a process called difference frequency generation. The size is similar to standard laser diode, and a wide spectral range has already been demonstrated (1 to 4.6 THz).

"Using a room-temperature mid-infrared laser to generate terahertz light bypasses the temperature barrier, and all we need to do is to make the output power high enough for practical applications," said Razeghi, who leads Northwestern's Center for Quantum Devices (CQD). "Most applications require a minimum of microwatt power levels, but, of course, the higher the better."

The achieved output power, 215 microwatts, is more than three times higher than earlier demonstrations. This dramatic boost is due to a number of novelties, including Cherenkov phase matching, epilayer down mounting, symmetric current injection, and anti-reflection coating.

The researchers will now work to achieve continuous wave operation and incorporate tuning in the device.

.


Related Links
Northwestern University's McCormick School of Engineering and Applied Science
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Toxicologist says NAS panel 'misled the world' when adopting radiation exposure guidelines
Amherst MA (SPX) Aug 15, 2013
In two recently published peer-reviewed articles, toxicologist Edward Calabrese of the University of Massachusetts Amherst describes how regulators came to adopt the linear no threshold (LNT) dose-response approach to ionizing radiation exposure in the 1950s, which was later generalized to chemical carcinogen risk assessment. He also offers further evidence to support his earlier assertion ... read more


TECH SPACE
Circadian rhythms in skin stem cells protect us against UV rays

Northwestern Researchers Develop Compact, High-Power Terahertz Source at Room Temperature

Thousands march in Romania against Canadian mine plan

Ultraviolet light to the extreme

TECH SPACE
Third Advanced EHF Satellite Will Enhance Resiliency of Military Communications

USAF Launches Third Advanced Extremely High Frequency Satellite

Atlas 5 Lofts 3rd AEHF Military Comms Satellites

Unified Military Intelligence Picture Helping to Dispel the Fog of War

TECH SPACE
Sunshield preparations bring Gaia closer to deep-space Soyuz launch

SES-8 Arrives At Cape Canaveral For SpaceX Falcon 9 Launch

Spaceport Colorado and S3 Sign Memorandum of Understanding

Milky Way-mapping Gaia receives its sunshield

TECH SPACE
Plan maps development of China's sat-nav industry

Raytheon completes critical design review for GPS OCX software

Tracking devices to go toe-to-toe with smartwatches

Orbcomm Acquires The SENS Asset Tracking Operation

TECH SPACE
Israel to make helmets for US F-35 fighter

Studies: Cargo aircraft demand to rise; light military helos to drop

Chinese group in $1.2 bn British airport development deal

F-35 Lightning II Program Surpasses 10,000 Flight Hours

TECH SPACE
CU, MIT breakthrough in photonics could allow for faster and faster electronics

Researchers demonstrate 'accelerator on a chip'

Spirals of Light May Lead to Better Electronics

Promising new alloy for resistive switching memory

TECH SPACE
DroneMetrex Accomplishes Another Mapping Project Using Its Unique Topodrone-100

Flood maps from satellite data can help emergency response

Japan takes issue with Google maps over islands: reports

Australia's new prototype vehicle to improve Earth observation satellites' accuracy

TECH SPACE
WHO launches drive against mercury thermometers

Mongolia's 'eco-Nazis' target foreign miners

Minamata mercury treaty signed at UN conference

Minamata: The dark side of Japan's industrialisation




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement