Naming nanolasers

My Photonic Frontiers article coming up in the September issue of Laser Focus World describes recent progress on nanoscale lasers, having volumes smaller than a cubic wavelength. Such emerging technologies are fascinating, but also raise a peculiar problem for those of us who write about them: what do we call the things?

Some groups call their nanoscale lasers "spasers," an acronym for Surface Plasmon Amplification by the Stimulated Emission of Radiation. Surface plasmons are involved in the process, and the catchy term has gained its own Wikipedia entry, some 266,000 hits in a web search, and a fair amount of press coverage even before a paper in the July 27 issue of Science. Score a few points for savvy PR.

But other researchers prefer more general terms like "nanolasers." One reason is that the acronym for spaser defines a specific process--surface plasmon amplification by stimulated emission of radiation. Yet it's not clear that all nanoscale lasers demonstrated so far rely in that process, and some researchers wonder how stimulated emission in a tiny piece of semiconductor can amplify a surface plasmon, which is a group of oscillating electrons on a conductive surface.

A second reason is more philosophical, that "laser" has become a generic term. As Shaya Fainman of the University of California at San Diego (La Jolla, CA) told me, "any time I see light amplification by stimulated emission, I call it a laser." By that logic, if a nanoscale device is amplifying light by stimulated emission, it's a laser.

There are points to be made for both sides, but there also is another dimension to the discussion--defining a new term can be part of claiming credit for a discovery. The International Commission on Zoological Nomenclature has elaborate rules on the proper naming of living or extinct animal species. No such rules exist in physics, so terms compete on their own merits. Interestingly, Gordon Gould's term "laser" won the popularity contest over Charles Townes' original suggestion of "optical maser," but the Nobel Prize went to Townes.

Who eventually will be credited with inventing nanoscale lasers remains to be determined. For now, I'm using "nanolaser" as a generic term for nanoscale laser, as I did in an earlier article. But I'm also watching for future developments in the fast-moving field.

3D falls flat for Olympics

The past few years have seen some impressive innovations in three-dimensional displays. New digital projectors have made 3D movies come alive in theaters, and high-resolution flat-panel displays can bring 3D television to homes. Digital image processing and 3D helped make Avatar the highest-grossing movie of all time. At the peak of 3D enthusiasm, some in Hollywood predicted that soon 3D production would become standard for movies.

Live sports was supposed to be the next great frontier for 3D, and Panasonic and Olympic Broadcasting Services sent crews to London to record 200 hours of the Summer Olympics in 3D. But the effort seems to have fallen flat. Chris Chinnock reports on Display Daily that the BBC logged an average UK audience of 24 million people for the opening ceremonies, only 111,000 households watched the 3D simulcast, a figure he called "pretty dismal." My own informal poll of a small newsgroup discussing the Olympics found no one who cares about 3D, and one who had never bothered to set up the 3D on his Playstation 3. 

Why did 3D fall flat for the world's biggest sport spectacular? It's tempting to blame the lack of promotion, the difficulty of finding 3D coverage, and the decision to delay all 3D broadcasts by 24 hours. But the truth is that few people outside of the consumer industry show much interest in 3D television. Properly done, 3D can be fun—for a limited time. I enjoyed playing with a 3D set in the video store, but the amusement wore off in 15 minutes. I can see where the 3D versions of some movies might be worth a few extra dollars in the theater. But the monsters in the lap gimmick gets old fast, viewers dislike the active shutter glasses for 3D televisions, and too much intense 3D can cause eyestrain and nausea.





A refreshable holographic image of an F-4 Phantom jet is created on a photorefractive polymer. (Courtesy of the University of Arizona)


New technology from NLT Technologies (Kawasaki, Japan) presents different views to both eyes of several people, allowing them to see depth by the parallax effect without special glasses. However, that's no panacea because the brain senses depth in multiple ways, and conflicts between different cues lead to eyestrain, headache, and nausea. Perhaps we'll have to wait for further development of holographic video.