By Patricia Daukantas

The weather outside the Baltimore (U.S.A.) Convention Center has been varying wildly, from warm and summery to cool and rainy. Indoors, however, the atmosphere of the CLEO:2011 conference was steadily abuzz with exciting applications of the latest photonics technologies.

Ultraviolet LEDs Can Disinfect Water

Although CLEO is primarily a laser conference, some tracks focused on other photonics technologies, such as photovoltaics and quantum computing. Following a joint symposium on semiconductor ultraviolet (UV) lasers and LEDs, a session reviewed several practical applications of UV LEDs.

One task for which these devices are particularly suited is the removal of harmful germs and other contaminants from drinking water. Gordon Knight, a research manager at Trojan Technologies (Canada), explained that UV light penetrates the cell membranes of bacteria, viruses and protozoa and permanently alters their DNA so the critters can’t reproduce and infect humans. UV rays can also break down organic contaminant molecules, as long as the molecular absorption spectrum matches the output of the UV sources.

Water treatment specialists are primarily interested in the UV-C spectrum (200 to 280 nm), in which the peak absorption spectrum of germ DNA falls, Knight said. The industry’s workhorse has been the low-pressure mercury arc lamp, which has a strong emission peak at 254 nm. However, solid-state UV sources could be more energy-efficient and could maintain their steady output for five times longer than the mercury lamps.

Although some technical challenges remain in the development of UV-C LEDs--namely, cost and the need to boost individual chip output above 5 mW--Knight is confident that these sources will provide efficient instant-on operation for future water treatment devices, both in municipal plants and perhaps even in household-sized systems.

IARPA: An Opportunity, Not a Misspelling

You’ve heard of DARPA, but what about IARPA? The Intelligence Advanced Research Projects Agency, a new branch of the U.S. government’s spy agencies, recently started searching for “high-risk, high-payoff” research programs to boost America’s intelligence-gathering efforts.

According to IARPA official Michael C. King, the agency is especially interested in significant advances in techniques to gather biometric data from distant, moving human subjects. Successful proposals require not just a good idea, but also a capable leader to guide the research project. One U.S. team followed King’s talk with a discussion of their own technique for so-called “standoff biometric identification” of people. According to Brian C. Redman of Lockheed Martin (U.S.A.), Fourier transform profilometry involves bouncing fringes from an 808-nm laser off the subject, capturing it and its two-dimensional fast Fourier transform, then doing an inverse transform and merging it with the original data. The laser pulses are eye-safe and, with a duration of 100 microseconds, short enough to freeze motion at a brisk walking speed of 1.5 m/s. The near-infrared light can even “see” through most sunglasses, Redman said.

Applied optics, Biomedical optics, CLEO/QELS, Energy, Lasers, Lasers, CLEO, OSA, Photovoltaics lasers, cleo, the optical society, optics & photonics news, quantum computing, biomedical optics, photovoltaics

By Patricia Daukantas

A smorgasbord of recent developments in U.S. energy policy, astrophysics and the deep sea:

• The barren desert that once hosted hundreds of nuclear fission explosions will become a testing ground for collecting energy from that ultimate source of fusion power, the Sun. The U.S. Department of Energy has announced it is creating a solar energy demonstration zone at the Nevada Test Site. U.S. Energy Secretary (and OSA Honorary Member) Steven Chu recently signed an agreement with his counterpart at the Interior Department, which owns the land. The 25 square miles of desert, which is away from the regions of the test site that actually saw nuclear explosions, will host demonstrations of concentrated solar power (CSP) technologies.
• The Hubble Space Telescope’s master repairman has gotten himself a second ground-based gig. John Grunsfeld, who has made three space trips to fix and upgrade the 20-year-old orbiting instrument, will be a research professor of physics and astronomy at Johns Hopkins University in Baltimore, Md., U.S.A. Grunsfeld, an astrophysicist by training, now serves as deputy director of the nearby Space Telescope Science Institute.
• Finally, I stumbled upon this nifty Q&A with Emory Kristof, the National Geographic contributing photographer-in-residence whose photographs appeared in the cover story of OPN’s October 2005 issue. You can also check out his photo gallery, “Discovering the Titanic,” and some of his images are included in “Milestones in Underwater Photography” as well.

2010-07 July, Astrophysics, Energy, Photography steven chu, energy, energy policy, solar power, hubble, hubble space telescope, photography

By Patricia Daukantas

Since we’re just past the summer solstice in the Northern Hemisphere, it seems appropriate that solar-powered vehicles are sailing through the news.

First of all, the University of Michigan’s solar car team, based in Ann Arbor (U.S.A.), won last week’s American Solar Challenge road race through heartland America, from Tulsa, Okla., to Naperville, Ill.

Michigan was one of 17 competing teams, mostly from the United States, but also representing Canada, Germany and Taiwan. The University of Minnesota (U.S.A.) finished in second place and the Hochschule Bochum – Bochum University of Applied Sciences (Germany) came in a strong third, less than 10 minutes behind Minnesota.

Although the winner’s elapsed racing time was just under 28 hours and 15 minutes, the race took a full week to complete, because of the mandatory checkpoints and overnight stops along the winding route.

Check out the photos of the Michigan car and its rivals in the links above – from the front, the Michigan vehicle looks to me like one of the UFOs from sci-fi movies of the 1950s, and from the side, it looks a bit like a small boat on wheels. Plus, the tiny compartment for the driver ensures that the car will never become the family sedan of the future. Still, one can’t argue with success.

Another solar-vehicle race – this one for high school students – will take place July 18-25 on steeper American terrain (Fort Worth, Texas, to Boulder, Colo.). Twenty-two teams have applied to take part in the Hunt-Winston School Solar Car Challenge. Yes, the drivers of the cars actually do have to have their driver’s licenses. But it’s still amazing what these teenagers can do.

Finally, the Japan Aerospace Exploration Agency, or JAXA, has deployed a solar sail in outer space. Its unpiloted satellite, IKAROS, was launched six weeks ago and had to “stretch its wings” once it got several million kilometers away from Earth. JAXA will monitor the output of the thin-film solar cells and learn how to maneuver with the combined force of radiation pressure on the sails and the energy generated from the photovoltaic sail. The agency explains how the sail was deployed and has a website with other details of the mission.

2010-07 July, Energy, Miscellaneous Optics solar power, students, energy, energy policy

By Patricia Daukantas

OSA Honorary Member Steven Chu, director of the Lawrence Berkeley National Laboratory in California, is President-elect Barack Obama’s choice to lead the U.S. Department of Energy.

Democratic officials announced Obama’s environmental team to the media last night, according to the Washington Post, the New York Times and CNN.

Chu, Claude Cohen-Tannoudji and William D. Phillips shared the 1997 Nobel Prize in physics for their work in laser cooling and trapping atoms. OSA named Chu a Fellow in 1991 and an Honorary Member in 2003. In 1994, he received OSA’s William F. Meggers Award for outstanding work in spectroscopy.

At Frontiers in Optics 2006, OSA’s 90^th annual meeting, Chu gave a plenary talk devoted to energy efficiency and the search for alternative fuels, including solar energy.

2008-12 December, Energy, OSA steven chu, fio, osa, energy, energy policy

By Patricia Daukantas

This year’s OSA congressional caucus briefing covered an extremely timely topic: solar energy. Last Friday, several policy analysts and industry representatives touted the benefits of both photovoltaic (PV) and concentrating solar power (CSP) technologies to congressional staff members.

Doug Hall, director of PV technologies for Corning Inc., explained to the Capitol Hill audience how PV devices work and how they have evolved from wafered silicon to thin-film panels. Nanotechnology, organic materials and flexible substrates—all of which have been described in OPN over the past few years—could eventually bring greater efficiency and lower costs.

CSP, on the other hand, uses reflecting troughs, reflecting dishes, Fresnel lenses or similar devices to direct incoming solar energy to a single place such as a power plant. The technology makes it easier to store the energy for use during cloudy days or at night, according to Chuck Kutscher of the U.S. National Renewable Energy Laboratory.

Other speakers addressed federal and private-sector investments in the various types of solar systems. OSA, who co-hosted the event with the Environmental and Energy Study Institute, has posted the viewgraphs from the congressional briefing on its Web site.

2008-07 July, Energy energy policy, lighting, leds

By Patricia Daukantas

Once again, it’s time for CLEO/QELS and PhAST. These three conferences, taking place this week in California’s Silicon Valley, are just a few miles from Lawrence Livermore National Laboratory and the site of the National Ignition Facility, where the world’s largest laser system is being built.

NIF is just one of the big, cool new projects highlighted at the 2008 Conference on Lasers and Electro-Optics and Quantum Electronics and Laser Science. Plenary speaker David Reitze of the University of Florida, who is featured in the current issue of OPN, awed the audience with a description of gravitational waves and the amazing precision that the Laser Interferometer Gravitational-Wave Observatory (LIGO) needs to detect such waves.

Several representatives from the solar and solid-state lighting industries treated the CLEO/QELS media contingent to an exclusive discussion of new technologies for energy efficiency. Environmentally friendly technology is here to stay, according to Scott Clavenna, president and CEO of Greentech Media, because governments worldwide have accepted climate change as a fact and businesses and consumers are demanding green solutions. Fossil fuel prices will remain highly volatile for the foreseeable future and may eventually be subject to a carbon tax. Optoelectronics intersects with green technology in a number of areas, from closed-loop energy-control systems to solid-state lighting modules and telecom applications.

Richard Sandberg of JILA and the University of Colorado at Boulder (USA) has been chosen the winner of the annual OSA-New Focus/Bookham Student Award, which recognizes excellence in research by students. Sandberg used curvature correction and high-numerical-aperture imaging to demonstrate a soft-x-ray diffraction microscope with near-diffraction-limited resolution of 70 to 90 nm. Sandberg received the top prize of $5,000, while six other finalists from universities in the United States and United Kingdom garnered $1,500 each.

Coherent Inc. won this year’s PhAST/Laser Focus World Innovation Award for its optically pumped semiconductor laser technology, which has improved the treatment of one type of age-related macular degeneration. The 2008 Photonic Applications, Systems and Technologies conference had a large number of tracks on organic and inorganic LEDs, high-power lasers and solar-power technology.

We’ve got other technical highlights from CLEO/QELS and PhAST on the Web, and Susan Curtis of Optics.org has been blogging about the conferences.

Plenary speaker David Reitze of the University of Florida.

2008-05 May, CLEO/QELS, Energy, Lasers, CLEO cleo, cleo/qels, green, energy, lighting

By Patricia Daukantas

The comprehensive energy bill that President Bush signed into law yesterday contains two major provisions concerning lighting technology.

The first clause requires that federal civilian buildings change over to more energy-efficient lighting, such as compact fluorescent lamps (CFLs) and other bulbs with the Energy Star designation. Based on legislation submitted earlier this year by Rep. Bob Inglis (R-S.C.) and Rep. Dan Lipinski (D-Ill.), the provision affects the 1,800 buildings managed by the General Services Administration. The government will be replacing up to 3 million light bulbs with more efficient models as the old bulbs burn out.

“If you’re the landlord and have the opportunity to save $74 per light bulb, it really isn’t a very hard decision,” Inglis said at a press conference yesterday after the House of Representatives approved the final version of the legislation. “We’re the landlord in a lot of properties.”

Lipinski noted that the House changed over to CFLs earlier this year. A similar provision in the Defense Department appropriations bill will cover military buildings.

The other lighting-related portion of the bill effectively phases out the use of low-efficiency incandescent bulbs over the coming decade. It doesn’t explicitly outlaw incandescents; it just mandates a high lumens-per-watt rating for certain types of light bulbs starting in 2012. The efficiency requirements will be phased in gradually through 2014.

U.S. News & World Report has already posted a Q&A on “the end of the light bulb as we know it.” Watch OPN for an upcoming article on the new light-bulb efficiency regulations and what they mean for the lighting industry.

2007-12 December, Energy lighting, leds, energy policy

By Patricia Daukantas

On the National Mall, practically on the doorstep of Washington, D.C.’s decision-makers, 20 teams of undergraduate and graduate students have spent the past week living on solar power.

The third-ever Solar Decathlon pits the collegians from the United States, Canada, Germany and Spain in a competition to design the kinds of completely solar-powered houses that our great-grandchildren may someday live in.

The Solar Decathlon gets its name from the 10 separate categories in which entries are judged: architecture, engineering, market viability, communications (with the public), comfort zone, appliances, hot water, lighting, energy balance and getting around (in small, street-legal electric vehicles powered off the house’s solar-power supply). As in the Olympic track-and-field decathlon, each contest nets the competitor a certain number of points, but there can be only one victor.

The categories reflect the notion that, to be successful, a solar-powered house must actually be comfortable to live in. It can’t be too hot or too cold, it must provide enough hot water for the dishwasher and the showers, and it should look reasonably attractive.

Two years ago, when I wrote about the 2005 Solar Decathlon, the weather had been cloudy for nearly the entire competition, and team members struggled to capture the available photons. This year, drought conditions in the mid-Atlantic region have caused plenty of clear October skies—and a lot more sunshine to work with for most of the week. (Cloudy weather rolled in yesterday, with some light rain today.)

Early in the week, the team from the Technical University of Darmstadt, Germany, was in the top spot. But after winning the communications contest, the University of Maryland—which, with its location in the Washington suburbs, is effectively the home team—took the lead and kept it for several days. Late this afternoon, however, Darmstadt was declared the overall victor.

Maryland’s so-called LEAF House uses 34 Sanyo HIT-205BA3 photovoltaic (PV) panels, which together generate 6,970 W of electricity in full sunshine. Low-mercury fluorescent bulbs and reflectors provided the overall indoor lighting with heavy use of LEDs, attached to a central dimming system, for task lighting.

The Darmstadt students, who had to send their entry across the Atlantic via container ship, placed Schott amorphous silicon PV panels on three sides of their house to supplement the 40 Sunpower SPR-210 roof-mounted panels. The team integrated LEDs into the ceiling, furniture and deck while providing ambient lighting through translucent wall panels.

Similar details on the other 18 houses in the competition—plus information on scoring criteria, blog entries and lots of photos—are available through links from the main Solar Decathlon Web site.

The Solar Decathlon is already accepting proposals for the October 2009 competition. The chosen participants will get a two-year, $100,000 grant toward solar-technology research. Also, American and Spanish officials are beginning plans for a European Solar Decathlon in 2010.

If you are near Washington and want to check out this year’s crop of futuristic homes, better move fast—tomorrow’s the last day of public display. 

 
The solar village at night takes on a different appearance, especiallywhen the houses are lit up for the Lighting contest. In this photo, theCarnegie Mellon house looks lovely in the glow cast on the greenscape.(Credit: Kaye Evans-Lutterodt/Solar Decathlon)

2007-10 October, Energy solar power, energy, everyday life, lighting, education