Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



TECH SPACE
From unconventional laser beams to a more robust imaging wave
by Staff Writers
Rochester NY (SPX) Aug 10, 2016


Creating a more robust terahertz wave from an Airy beam. Image courtesy Michael Osadciw/University of Rochester. For a larger version of this image please go here.

Here's the scene: a suspicious package is found in a public place. The police are called in and clear the area. Forced to work from a distance and unable to peer inside, they fear the worst and decide to detonate the package.

New research at the University of Rochester might help authorities in the not-too-distant future be better informed in tackling such situations and do so more safely. Working with a special type of electromagnetic wave--called terahertz (THz)--that's capable of sensing and/or imaging objects behind barriers, the team demonstrated that they can detect a THz wave at a distance of up to 100 feet.

The THz wave created by the researchers is more than five times stronger than what is generated by more conventional means, leading them to believe that a THz wave--and the image of a hidden object--can be detected at much greater distances in the future.

The research project was led by Kang Liu, a PhD student in optics, and Xi-Cheng Zhang, the M. Parker Givens Professor of Optics and the director of the Institute of Optics, in collaboration with a group from Greece led by Tzortzakis Stelios. The results have been published in the journal Optica.

"The use of an unconventional laser beam in our project goes beyond a scientific curiosity," said Zhang. "It makes possible the remote sensing of chemical, biological, and explosive materials from a standoff distance."

THz waves, which fall between microwave and the infrared band on the electromagnetic spectrum, can penetrate certain solid objects that are opaque to visible light to create images of what is hidden from view. Unlike traditional x-rays, the waves do so without damaging human tissue. All that makes THz waves a promising tool for Homeland Security and other law enforcement agencies. But before THz waves can be widely used, a number of obstacles need to be overcome, including how to make them more effective over greater distances.

One of the drawbacks is that the waves are absorbed by water molecules in the air and weaken significantly over longer distances, making them generally ineffective. One solution is to generate the THz waves near the target, so that they have only a short distance to travel. It's also important that the waves are intensive, because, as Liu points out, "The stronger the terahertz wave, the more work it can do."

The key to their results was the use of a specific exotic laser beam--called a ring-Airy beam--to generate a THz wave that has 5.3 times the pulse energy of THz waves created with standard Gaussian beams.

Ordinary beams of light spread out as they travel, but that's not the case with ring-Airy beams, which curve toward the center from all points.

To begin the process, Liu directed a laser beam onto a spatial light modulator (SLM), which formed the ring-Airy beam. As the name indicates, the beam is circular with a hollow center. Instead of spreading out as it travels, the beam collapsed inward, creating an intensely excited region of free electrons--called a plasma. Those electrons, in turn, generated the THz wave, which would be capable of penetrating a nearby target and reflecting images or providing vital chemical information about what is hidden.

"When the target is a suspected explosive device, it's important to get the work done at a safe distance," said Liu. "We believe our method could help THz remote sensing from more than 100 feet away by providing a more robust and flexible way to generate THz remotely."

The modulator allowed the researchers to change the size of the ring-Airy beam and fine-tune the dimensions of the plasma that is created. The next step, as Liu sees it, is to manipulate ring-Airy beams to create stronger THz waves over greater distances.

Funding for the research project was provided by the US Army Research Office, "Laserlab-Europe", and the General Secretariat for Research and Technology Aristeia project "FTERA."

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of Rochester
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

Previous Report
TECH SPACE
Physicists set low temperature record using laser cooling
Albuquerque (UPI) Aug 2, 2016
Researchers at the University of New Mexico are using optical refrigeration to set low-temperature records. Physicists there recently used lasers to cool a special crystal to temperatures below 100 degrees Kelvin - colder than the Arctic Circle. The technology includes no moving parts, making it ideal for applications in especially sensitive detectors and sensors. "Right now, an ... read more


TECH SPACE
Heart hazard for Apollo astronauts: study

Asteroid that formed moon's Imbrium Basin may have been protoplanet-sized

Russian and US engineers plan manned moon mission

SSTL and Goonhilly announce partnership and a call for lunar orbit payloads

TECH SPACE
Digging deeper into Mars

Engine burn gives Mars mission a kick

NASA's Viking Data Lives on, Inspires 40 Years Later

Opportunity Rover wrapping up work within Marathon Valley

TECH SPACE
Tile Bonding Begins for Orion's First Mission Atop Space Launch System Rocket

Russia, US Discuss Lunar Station for Mars Mission

Disney theme park in Shanghai nears a million visitors

NASA Sails Full-Speed Ahead in Solar System Exploration

TECH SPACE
China to expand int'l astronauts exchange

China's Agreement with United Nations to Help Developing Countries Get Access to Space

Chinese tracking ship Yuanwang-7 starts maiden voyage

Chinese mega-telescope obtains data on 7 million stars

TECH SPACE
Dream Chaser Spacecraft on Track to Supply Cargo to ISS

Russia launches ISS-bound cargo ship

New Crew Members, Including NASA Biologist, Launch to Space Station

Russian New Soyuz-MS Spacecraft Docks With ISS for First Time

TECH SPACE
Russia Postpones Launch of Proton Rocket With US Satellite Until October 10

The rise of commercial spaceports

India earned Rs 230 crore through satellite launch services in FY16

US Plan to Diversify Expendable Space Launch Vehicles Being Questioned

TECH SPACE
Alien Solar System Boasts Tightly Spaced Planets, Unusual Orbits

NASA's Next Planet Hunter Will Look Closer to Home

First atmospheric study of Earth-sized exoplanets reveals rocky worlds

Atmospheric chemistry on paper

TECH SPACE
Hot 'new' material found to exist in nature

Flexible building blocks of the future

A mini-antenna for the data processing of tomorrow

New metamaterials can change properties with a flick of a light-switch




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






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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