In perhaps their greatest success, Sandia researchers Shawn Lin (1712) and Jim Fleming (1723) have created a three-dimensional photonic crystal that confines light at optical wavelengths. 

The proof-of-principle device may prove commercially important to the fiber-optics communications industry because the technique it embodies appears to be the cheapest, most efficient way to bend light entering or emerging from optical cables, says Shawn.

The crystal — really a three-dimensional artificial lattice — was fabricated by Jim and a silicon processing team using advanced techniques in Sandia’s Microelectronics Development Laboratory.

The result is a kind of microscopic tunnel of silicon slivers with a 180-nanometer minimum feature size. The structure is nearly 10 times smaller than the device the Sandia researchers recently reported in Nature (Lab News, Sept. 11).

The lattice’s creation crowns a quest in U.S. laboratories that began 10 years ago with the simple idea that a light-containing artificial crystal was possible. "In my mind," says Shawn, "We are on holy ground. We are the lucky ones who got to the moon first."

"The present structure is a monumental achievement," says Sandia manager Del Owyoung (1710). "It’s a fabrication that researchers have been trying to achieve for a decade."

The lattice is the smallest three-dimensional crystal ever achieved with a complete three-dimensional photonic band gap and is effective at wavelengths between 1.35 and 1.95 microns.

A paper on the achievement will be published in the Jan. 1 Optics Letters.

Papers on larger-dimensioned photonic successes by Sandia appeared earlier this year in Nature and Science(Lab News Oct . 9).

Still to be achieved is the insertion of a defect that can transmit and bend light within the lattice structure.