By Patricia Daukantas

Greetings! Since OSA headquarters will be closed next week for the holidays, this will most likely be the last OPN blog post in 2009.

It’s been quite a year for this blog, with coverage of OSA’s three major conferences: OFC/NFOEC (thanks to C. David Chaffee of FiberToday.com), CLEO/IQEC and FiO/LS. The International Year of Astronomy (IYA) provided the inspiration for several blog posts related to sky observing and light pollution. And we tried to bring you some breaking news from the world of optics and photonics, plus a few items from the “lighter side.”

Readers of this blog and my OPN articles are probably aware that I have a soft spot for amateur astronomers who participate in scientific research. (See “The Professional World of Amateur Astronomy” in the March 2009 issue of OPN.)

Just last week a team of astronomers announced the discovery of a “super-Earth,” only about 6.5 times as massive as our planet, orbiting a dim red star some 40 light-years from Earth. Although those discoverers are all professionals and grad students, they used a network of commodity 16-inch telescopes and CCD cameras that are well within the reach of amateur stargazers.

Interested in pursuing a similar project? Take a look at the original Nature article or the review by the well-known planet-hunter Geoffrey Marcy of the University of California at Berkeley (U.S.A.).

Now on to 2010: who knows what the future will bring? The IYA is coming to an end, with closing ceremonies scheduled for next month in the Italian town where Galileo taught physics, and a legacy program called Beyond 2009 will continue to raise public awareness of astronomy.

Meanwhile, LaserFest 2010 will start in January with events in every month – check the Web site for details.

Happy New Year to all OSA members and their families and friends!

2009-12 December astronomy, laserfest

By Patricia Daukantas

We in the optics community all know the spiel: Solid-state lighting is better than incandescent lighting because the latter wastes a log of energy as heat. But where might hot light bulbs actually be a good thing?

The answer: in traffic lights that get exposed to a lot of ice and snow. According to news reports that have appeared over the last couple of days, LED-illuminated traffic signals don’t generate enough heat to melt off the ice and snow that get stuck to the signal lenses during a storm. Such a frozen crust can make the lights difficult or impossible for motorists to see.

According to one story datelined Milwaukee (Wisconsin, U.S.A.), public-works authorities in several states are testing out possible methods of keeping LED traffic lights cleaned off: weather shields, special heating units like the ones in airport runway lights, or water-repellent coatings. But mainly, they’re resorting to good old-fashioned manual labor to clear off the ice and snow. (Remember, one of the advantages of LEDs is that they don’t have to be replaced anywhere nearly as often as incandescent bulbs.)

That news article also cites the case of a woman in Oswego, Illinois (U.S.A.), who was killed while making a left turn at an intersection where the signals were mostly covered with snow.

The red, yellow and green lights on most American traffic signals have metal hoods to help drivers see the lights even in bright sunlight. However, those hoods don’t help as much when the snow is blowing horizontally in a blizzard.

Then again, Denver (Colorado, U.S.A.), a burg that most people associate in their minds with snow and skiing, hasn’t been having much of an icing problem with its LED signals. According to the Denver Post news brief, “Denver, with its freeze-thaw cycle, is blessed with a weather pattern that prevents the energy-efficient lights from icing over for long periods.”

2009-12 December led, leds, solid-state lighting, energy, green

By Patricia Daukantas

As the end-of-year holidays approach, I thought I’d revisit a few seasonal subjects that have appeared in OPN issues past.

For instance, PhysicsSongs.org (the Scatterings column, December 2005) is still up and running at Haverford College (Pennsylvania, U.S.A.). Of course, the Web site contains lyrics and songs concerning all branches of physics, not just optics, and many of the tunes have nothing to do with Christmas. Still, you may be interested in this PDF sing-along sheet featuring “Rudolph, the Bright Red Photon,” or maybe these carols, including “Phrosty the Photon” and “Speedy the Visible Light Ray.” People who remember our historical feature article on Ole Rømer in the July/August 2009 issue might especially like these lyrics:

Then one foggy physics eve, Roemer came to say,
"Speedy with your light so bright, let me time your speed tonight."
Then all the other wavelengths, said with all their energy,
Speedy the Visible Light Ray, we'll see you in the lab-'ra-tor-Y!!

Also from Scatterings, December 2006: The researcher behind SnowCrystals.com, Caltech physicist Kenneth Libbrecht, has published several more popular-level books featuring his beautiful snowflake photographs since he was featured in OPN three years ago. His Web site also discusses the physics of snowflake formation and explains how he photographs those tiny, delicate crystals. In his warm-weather day job (Pasadena, Calif., U.S.A.), Libbrecht is one of several hundred collaborators on the Laser Interferometer Gravitational-wave Observatory (LIGO) project.

Finally, if your December is sunny and hot rather than snowy and cold, take a look at the really hot, young stars in this Hubble Space Telescope “picture postcard,” featuring a cluster surrounded by red and green gas in the region of the Large Magellanic Cloud known as the 30 Doradus Nebula.

These blue stars, which are some 163,000 light-years from our Sun, have a surface temperature of some 50,000 K and are among the most massive stars ever found by humans. Such massive stars use up their nuclear fuel much more quickly than the Sun; as somebody wrote in the press release accompanying the photo, “These hefty stars are destined to pop off, like a string of firecrackers, as supernovas in a few million years.”

Hubble’s Wide Field Camera 3 – which was installed during the final NASA servicing mission this past spring – took the ultraviolet and infrared images that make up this composite portrait of 30 Doradus, and an international (U.S.A., Switzerland, Wales, Australia and Germany) team assembled the final picture.

2009-12 December hubble space telescope, astronomy, snowflakes, nature, education

By Patricia Daukantas

To reach more members of the worldwide optics and photonics community, I'm trying to get the OPN blog listed on Technorati.com. I need to publish a specific code to prove I'm the blog writer -- JRPH6NF3RVM7 -- let's see if this works.

(Don't forget: you can also keep abreast of breaking optics news by following OPN's feed on Twitter: @OPNmagazine.)

2009-12 December social networking

By Patricia Daukantas

Two University of Rochester (New York, U.S.A.) scientists who figured out how to blacken metals with femtosecond lasers have found that these treated metals absorb radiation all the way into the terahertz region of the electromagnetic spectrum. The finding could lead to new kinds of medical detectors.

Associate professor of optics Chunlei Guo, research assistant Anatoliy Vorobyev and three colleagues at V.N. Karazin Kharkov National University (Ukraine) recently published an article on the enhanced absorption of metals after femtosecond laser microstructuring technique.

Obviously, any object that we call “black” has that color because it absorbs light at visible wavelengths. The Rochester-Karazin team used a laser-calorimetry method to measure the absorptance of blackened tungsten samples, which were patterned with grooves with periods of 66, 120 and 430 µm. They measured the materials’ absorption of terahertz radiation with wavelengths of 70.7 and 118.8 µm (4.24 and 2.53 THz, respectively).

The highest absorptance they recorded was 51 percent of the 70.7-µm radiation by the 120-µm-grooved surface. By contrast, the authors write, metals are virtually perfect reflectors of far-infrared and terahertz radiation. Further spectral studies showed that the blackened tungsten absorbs radiation at wavelengths into the terahertz region.

Some experts say that the terahertz-absorbing materials could be used in medical equipment that could detect pathogens at the cellular level.

OPN first wrote about the metal-blackening work of Guo and Vorobyev in the Scatterings column of the February 2007 issue. I described some additional work of theirs – making metals look colored, not just black, with the laser technique – in a February 2008 blog post that also mentioned a popular article in the New York Times. Finally, the pair’s work was summarized in the Optics in 2007 and Optics in 2008 issues of OPN.

2009-12 December femtosecond laser, materials science

By Patricia Daukantas

Tomorrow the 2009 Nobel Prize winners will get their awards in a formal ceremony, but their Nobel lectures, delivered yesterday in Stockholm (Sweden), are now online at Nobelprize.org.

Gwen M.W. Kao gave one address on behalf of her husband, Charles K. Kao, who received half this year’s physics prize for his pioneering work in optical fiber communications. If you go to page 24 of the PDF of her slides, you can see a photo of a younger Kao (he’s now 76) at an early OFC conference. (Late 1970s? The date’s not specified.) Mrs. Kao spoke of her husband’s persistence in getting other people to recognize the potential of the small glass waveguides for telecommunications.

Willard S. Boyle, one of two laureates for inventing the charge-coupled device, called the CCD “an extension of man’s vision,” and his colleague and fellow laureate, George E. Smith, reviewed the evolution of the CCD from the first crude devices to the first self-contained camera and to modern applications of the technology.

Clicking on each physics laureate’s name in this post will take you to the corresponding Nobel lecture page. From there, you can link to a video of each presentation – brought to you, of course, by the technologies that are being celebrated.

2009-12 December nobel, ccd, fiber optics

By Patricia Daukantas

Last month, OSA’s 93^rd annual meeting, Frontiers in Optics (FiO), featured more social networking than any of its predecessors. This week, however, a group of astronomers is holding a meeting devoted just to social networking and “Web 2.0” activities within that branch of science.

The second-ever .Astronomy (pronounced “dot-astronomy”) conference started today at Leiden University in the Netherlands. Building on last year’s gathering in Cardiff, Wales, the participants are talking about new ways of communicating astronomical science to the public, ranging from online robotic telescopes to the large image collections of Google Sky and Microsoft’s WorldWide Telescope to the communications media of blogging, podcasting and the Twitterverse. Morning conference sessions are even being streamed on live video (European time).

(Incidentally, one Twitter member, @ninajansen, posted that she had just bought a Galileoscope as her first-ever telescope, even though her Ph.D. is in astronomy.)

After I read over the .Astronomy 2009 press release this morning, I was wondering what form a “.Optics” conference would take. How excited are you and your colleagues over the new social media? Do you blog, tweet or post on Facebook? Do you follow any optics- or photonics-related blogs, and if so, which ones? I know that OSA Fellow Pablo Artal blogs in both English and Spanish. The Florida Photonics Cluster, mentioned in my November 2009 Optics Innovations column, also has a blog.

What kinds of social media assist you in your optical science or engineering career? Please comment on this blog or on OPN’s “fan” page on Facebook.

2009-11 November blogging, social media