Now, researchers from Stanford University have greatly improved the optical mismatch between nanoscale objects and light by creating the "bowtie nanoantenna," a device 400 times smaller than the width of a human hair that can compress ordinary light waves into an intense optical spot only 20 nanometers wide. These miniature spotlights may one day allow researchers to produce the first detailed images of proteins, DNA molecules and synthetic nano-objects, such carbon nanotube bundles.
"One of our goals is to build a microscope with bowtie antennas that we can scan over a single molecule," says W.E. Moerner, the Harry S. Mosher Professor of Chemistry at Stanford. He and his Stanford colleagues introduced the bowtie nanoantenna earlier this year in a study published in the journal Physical Review Letters that was co-authored by postdoctoral fellow P. James Schuck and graduate student David Fromm in the Department of Chemistry, and Professor Emeritus Gordon Kino and graduate student Arvind Sundaramurthy in the Department of Electrical Engineering.
The bowtie nanoantenna consists of two triangular pieces of gold, each about 75 nanometers long, whose tips face each other in the shape of a miniature bowtie. The device operates like an antenna for a radio receiver, but instead of amplifying radio waves, the bowtie takes energy from an 830-nanometer beam of near-infrared light and squeezes it into a 20-nanometer gap that separates the two gold triangles. The result is a concentrated speck of light that is a thousand times mo
Contact: Mark Shwartz