News release below focuses on plasmons but the structure sounds very much like a Casimir cavity formed between the nanowire and silver surface with 5nm spacing. Maybe light just “upconverts” while in the cavity...
Plasmon Laser (Source: Courtesy of Xiang Zhang Lab, UC Berkeley) <http://www.dailytech.com/Researchers+Create+Worlds+Smallest+Semiconductor+Laser/article16122c.htm> DailyTech - Sep 1, 2009 Traditionally it is accepted that light can be compressed into a space smaller than half the size of its wavelength. Researchers have been able to compress light down to a couple nanometers by binding it to electrons that oscillate collectively along the surface of metals, otherwise known as plasmons. Zhang and his team improved on this technique by pairing a cadmium sulfide nanowire with a silver surface separated by an insulating gap only 5nm wide or about the size of a protein molecule. The structure is able to store the light within an area 20 times smaller than the wavelength of the light. The light energy is reportedly stored mostly in the insulating gap between the wire and the silver surface loss is diminished significantly.
