Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Green UV sterilization, MEGa-rays for nuclear detection, and cloaking 3-D objects: Research to be presented at CLEO: 2011 highlights latest advances in laser science

3-D Terahertz Cloak - Micrograph
Close-up micrograph of the bump region of the Terahertz cloaking structure. The size variations in the holes, which extend through the entire structure, is a key feature that guides the light around the bump, beneath which objects become invisible. The view is about 2 millimeters square.

Credit: Northwestern University/Ohio State University
3-D Terahertz Cloak - Micrograph

Close-up micrograph of the bump region of the Terahertz cloaking structure. The size variations in the holes, which extend through the entire structure, is a key feature that guides the light around the bump, beneath which objects become invisible. The view is about 2 millimeters square.

Credit: Northwestern University/Ohio State University

Abstract:
The world's foremost researchers in laser science, optoelectronics and quantum optics will present their findings at the Conference on Lasers and Electro-Optics (CLEO: 2011), May 1 - 6 at the Baltimore Convention Center. The more than 1,700 presentations at the conference will cover areas from energy and biophotonics to ultrafast lasers and quantum communication. Below is a sampling of the premiere research that will be presented next week at CLEO: 2011 (www.cleoconference.org).

* Green UV Sterilization: Switching on LEDs to Save Energy and the Environment
* Nuclear Photonics: Gamma Rays Search For Concealed Nuclear Threats
* 3-D Terahertz Cloaking
* Full 3-D Invisibility Cloak in Visible Light

Green UV sterilization, MEGa-rays for nuclear detection, and cloaking 3-D objects: Research to be presented at CLEO: 2011 highlights latest advances in laser science

Washington, DC | Posted on April 26th, 2011

Green UV Sterilization: Switching on LEDs to Save Energy and the Environment

Ultraviolet light can safely sterilize food, water and medical equipment by disrupting the DNA and other reproductive molecules in harmful bacteria. Traditionally, mercury lamps have supplied this UV light, however mercury release from power generation and lamp disposal have generated discussion of harmful environmental impact. A potentially energy efficient and non-toxic alternative is the light-emitting diode, or LED, which can be made to emit at almost any desired wavelength. LEDs are also more rugged and operate at lower voltages than glass containing mercury bulbs. Thus, LEDs are more compatible with portable water disinfection units, which could also be solar-powered and used in situations where centralized facilities are not available, such as disaster relief. LEDs currently require a lot of electricity to produce UV light, but researchers from around the world are focused on improving this efficiency.

LEDs are semiconductor devices that operate in much the same way as the tiny elements on a computer chip. The difference is that some of the electrons flowing into an LED are captured and release their energy as light. Because these are solid materials rather than gas-filled bulbs, LEDs are more compact and durable than alternative light sources. The first commercial LEDs were small red indicator lights, but engineers have developed new materials that emit in a rainbow of colors. Nitride-based LEDs are the most promising for pushing beyond the visible into the ultraviolet. Some of these UV LEDs are already being used in the curing of ink and the testing for counterfeit money, but for sterilization, shorter wavelength light is required. These short wavelength, or "Deep UV" LEDs, present a number of technical challenges and are predominantly implemented in highly-specialized disinfection systems in industrial and medical applications, as well as other non-disinfection markets.

The Joint Symposium on Semiconductor Ultraviolet LEDs and Lasers at CLEO: 2011 will feature several talks addressing these challenges, while highlighting current efforts to improve the efficiency of nitride-based LEDs. Max Shatalov of Sensor Electronic Technology in Columbia, S.C., will report an improved design for making high-power UV LEDs that would be especially good for knocking out bacteria. From the birthplace of nitride (blue and white) LEDs, Motoaki Iwaya from Meijo University in Japan will describe a joint effort with Nagoya University to extend the range and improve the efficiency of UV LEDs.

The application of these UV LEDs is also being pursued in a related CLEO: 2011 session. Gordon Knight from Trojan Technologies in Canada will review advances in production of novel UV light sources, along with necessary validation procedures for verifying the operation of water disinfection systems in a one-hour tutorial.

Presentation JTuD1, "High Power III-Nitride UV Emitters," by Max Shatalov et al. is at 11 a.m. Tuesday, May 3.

Presentation JTuD2, "IQE and EQE of the nitride-based UV/DUV LEDs," by Motoaki Iwaya et al. is at 11:30 a.m. Tuesday, May 3.

Tutorial ATuD1, "Water and Air Treatment Using Ultraviolet Light Sources," by Gordon Knight is at 1:45 p.m. Tuesday, May 3.

Nuclear Photonics: Gamma Rays Search For Concealed Nuclear Threats

Gamma rays are the most energetic type of light wave and can penetrate through lead and other thick containers. A powerful new source of gamma rays will allow officials to search for hidden reactor fuel/nuclear bomb material.

These gamma rays, called MEGa-rays (for mono-energetic gamma rays), are made by using a beam of fast-moving electrons to convert laser photons (light at a lesser energy) into the gamma ray part of the spectrum. The incoherent gamma rays can be tuned to a specific energy so that they predominantly interact with only one kind of material. A beam of MEGa-rays, for example, might be absorbed by the nuclear fuel uranium-235 while passing through other substances including the more common (but less dangerous) isotope uranium-238. That sort of precision opens the door to "nuclear photonics," the study of nuclei with light. "It is kind of like tunable laser absorption spectroscopy but with gamma-rays," says Chris Barty of Lawrence Livermore National Laboratory, who will present on MEGa-rays at CLEO: 2011.

In the last couple of years, MEGa-ray prototypes have identified elements like lithium and lead hidden behind metal barriers. The next-generation of MEGa-ray machines, which should come on-line in a couple of years, will be a million times brighter, allowing them to see through thick materials to locate specific targets in less than a second.

Barty will present several MEGa-ray applications in use today and will describe the attributes of next-generation devices. Work is under way on a MEGa-ray technology that could be placed on a truck trailer and carried out into the field to check containers suspected of having bomb material in them. At nuclear reactors, MEGa-rays could be used to quickly identify how enriched a spent fuel rod is in uranium-235. They could also examine nuclear waste containers to assess their contents without ever opening them up. MEGa-ray technology might also be employed in medicine to track drugs that carry specific isotope markers.

Presentation ATuF2, "Mono-Energetic Gamma-rays (MEGa-rays) and the Dawn of Nuclear Photonics," by Chris Barty is at 4:30 p.m. Tuesday, May 3.

3-D Terahertz Cloaking

Invisibility appears to be the next possible advance in the use of Terahertz radiation in medicine, security, and communications.

A research team from Northwestern and Oklahoma State universities claims to be first to cloak a three-dimensional object from view in a broad range of Terahertz frequency light, which lies between infrared and microwaves. In the team's paper at CLEO: 2011, Cheng Sun of Northwestern describes how a rigid sponge-like cloaking structure less than 10 millimeters long on a side was built up in 220 layers, each precisely defined to vary the index of refraction and bend light to render invisible anything located beneath a shallow concave bump on the cloak's bottom surface. The group showed that both the physical geometry and the spectrographic signature of a chemical strip about the width of 10 human hairs disappeared when cloaked.

Despite its Harry Potter-like allure, concealing tiny objects from view is not the team's ultimate goal, Sun said. Rather, this latest demonstration shows that the new "transformation optics" principles and 3-D lithography techniques they used to make the cloak can also enable optical components for guiding, collimating, and focusing terahertz light in a variety of ways—in new medical and scientific diagnostic tools, airport security scanners, and data communication devices.

Presentation, CWA5, "Three-dimensional Terahertz Cloak," by Cheng Sun et al. is at 1:30 p.m. Wednesday, May 4.

EDITOR'S NOTE: High-resolution images and diagrams of the 3-D Terahertz cloak are available. Contact Angela Stark,

Full 3-D Invisibility Cloak in Visible Light

Watching things disappear "is an amazing experience," admits Joachim Fischer of the Karlsruhe Institute of Technology in Germany. But making items vanish is not the reason he creates invisibility cloaks. Rather, the magic-like tricks are attractive demonstrations of the fantastic capabilities that new optical theories and nanotechnology construction methods now enable.

This new area, called "transformation optics," as the item just above also showed, has turned modern optical design on its ear by showing how to manipulate light in ways long thought to be impossible. They promise to improve dramatically such light-based technologies as microscopes, lenses, chip manufacturing and data communications.

In his CLEO: 2011 talk , Fischer will describe the first-ever demonstration of a three-dimensional invisibility cloak that works for visible light—red light at a wavelength of 700 nm—independent of its polarization (orientation). Previous cloaks required longer wavelength light, such as microwaves or infrared, or required the light to have a single, specific polarization.

Fischer makes the tiny cloak—less than half the cross-section of a human-hair—by direct laser writing (i.e. lithography) into a polymer material to create an intricate structure that resembles a miniature woodpile. The precisely varying thickness of the "logs" enables the cloak to bend light in new ways. The key to this achievement was incorporating several aspects of a diffraction-unlimited microscopy technique into the team's 3-D direct writing process for building the cloak. The dramatically increased resolution of the improved process enabled the team to create log spacings narrow enough to work in red light.

"If, in the future, we can halve again the log spacing of this red cloak, we could make one that would cover the entire visible spectrum," Fischer added.

Practical applications of combining transformation optics with advanced 3-D lithography (a customized version of the fabrication steps used to make microcircuits) include flat, aberration-free lenses that can be easily miniaturized for use in integrated optical chips, and optical "black holes" for concentrating and absorbing light. If the latter can also be made to work for visible light, they will be useful in solar cells, since 90 percent of the Sun's energy reaches Earth as visible and near-infrared light.

Presentation QTuG5 "Three-dimensional invisibility carpet cloak at 700 nm wavelength," by Joachim Fischer et al. is at 11 a.m. Tuesday, May 3. Fischer et al. will also present CML1, "Three-Dimensional Laser Lithography with Conceptually Diffraction-Unlimited Lateral and Axial Resolution," at 10:15 a.m. Monday, May 2.

###

CLEO: 2011 Program Information

CLEO: 2011 unites the fields of lasers and optoelectronics by bringing together all aspects of laser technology, from basic research to industry applications. The main broad topics areas at the meeting are fundamental science, science and innovations, applications and technology, and market focus. An exposition featuring 300 participating companies will be held concurrently with the scientific presentations.

Plenary Session keynote speakers include Donald Keck, retired vice president of Corning, talking about making the first low-loss optical fibers; James Fujimoto of MIT, talking about medical imaging using optical coherence tomography (OCT); Mordechai (Moti) Segev of the Technion-Israel Institute of Technology, speaking about the localization of light; and Susumu Noda of Kyoto University, talking about the control of photons in photonic crystals.

Online resources:

* Conference program: www.cleoconference.org/Conference_Program
* CLEO: Expo: www.cleoconference.org/exhibit_hall
* Press Center: www.cleoconference.org/media_center
* Plenary Session: www.cleoconference.org/Conference_Program
* Special Symposia: www.cleoconference.org/Conference_Program/symposia.aspx
* Conference Registration: www.cleoconference.org/registration

Press Registration

A Press Room for credentialed press and analysts will be located on-site in the Baltimore Convention Center, Sunday, May 1 - Thursday, May 5. Media interested in attending the conference should register online at www.cleoconference.org/media_center/mediaregistrationform.aspx or contact Angela Stark at 202.416.1443, .

####

About CLEO
With a distinguished history as the industry's leading event on laser science, the Conference on Lasers and Electro-Optics (CLEO) and the Quantum Electronics Laser Science Conference (QELS) is where laser technology was first introduced. CLEO: 2011 will unite the field of lasers and electro-optics by bringing together all aspects of laser technology, with content stemming from basic research to industry application. Sponsored by the American Physical Society's (APS) Laser Science Division, the Institute of Electronic Engineers (IEEE) Photonics Society and the Optical Society (OSA), CLEO: 2011 provides the full range of critical developments in the field, showcasing the most significant milestones from laboratory to marketplace. With an unparalleled breadth and depth of coverage, CLEO: 2011 connects all of the critical vertical markets in lasers and electro-optics.

For more information, please click here

Contacts:
Angela Stark

202-416-1443

Copyright © Optical Society of America

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Iranian Scientists Produce Reusable Nanoadsorbent to Detect Sulfamide in Chicken July 27th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Display technology/LEDs/SS Lighting/OLEDs

Martini Tech Inc. becomes the exclusive distributor for Yoshioka Seiko Co. porous chucks for Europe and North America July 20th, 2014

Carbodeon enables 20 percent increase in polymer thermal filler conductivity with 0.03 wt.% nanodiamond additive at a lower cost than with traditional fillers: Improved materials and processes enable nanodiamond cost reductions of up to 70 percent for electronics and LED app July 9th, 2014

'Nano-pixels' promise thin, flexible, high resolution displays July 9th, 2014

Projecting a Three-Dimensional Future: TAU researchers develop holography technology that could change the way we view the world July 9th, 2014

Announcements

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Iranian Scientists Produce Reusable Nanoadsorbent to Detect Sulfamide in Chicken July 27th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Environment

Researchers Use Various Zinc Oxide Nanostructures to Boost Efficiency of Water Purification Process July 13th, 2014

Using Sand to Improve Battery Performance: Researchers develop low cost, environmentally friendly way to produce sand-based lithium ion batteries that outperform standard by three times July 8th, 2014

Development of an interactive tool for the implementation of environmental legislation for nanoparticles manufacturers July 4th, 2014

Up in Flames: Evidence Confirms Combustion Theory: Berkeley Lab and University of Hawaii research outlines the story of soot, with implications for cleaner-burning fuels July 1st, 2014

Events/Classes

NNCO Announces an Interactive Webinar: Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy July 23rd, 2014

Harris & Harris Group to Host Conference Call on Second-Quarter 2014 Financial Results on August 15, 2014 July 23rd, 2014

Deadline Announced for Registration in 7th Int'l Nanotechnology Festival in Iran July 23rd, 2014

Iran to Hold 3rd Int'l Forum on Nanotechnology Economy July 22nd, 2014

Photonics/Optics/Lasers

NUS scientists use low cost technique to improve properties and functions of nanomaterials: By 'drawing' micropatterns on nanomaterials using a focused laser beam, scientists could modify properties of nanomaterials for effective applications in photonic and optoelectric applicat July 22nd, 2014

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Future Electronics May Depend on Lasers, Not Quartz July 17th, 2014

Quantum nanoscience

Physicists Use Computer Models to Reveal Quantum Effects in Biological Oxygen Transport: The team solved a long-standing question by explaining why oxygen – and not deadly carbon monoxide – preferably binds to the proteins that transport it around the body. July 17th, 2014

Bending the rules: A UCSB postdoctoral scholar in physics discovers a counterintuitive phenomenon: the coexistence of superconductivity with dissipation June 29th, 2014

Singapore Researchers Use FEI Titan S/TEM to Link Plasmonics with Molecular Electronics: As described in the March 28 issue of Science, researchers discover quantum plasmonic tunneling – a phenomenon that may eventually lead to new, ultra-fast electrical circuits June 24th, 2014

New quantum mechanism to trigger the emission of tunable light at terahertz frequencies June 18th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE