Sign In

Communications of the ACM

ACM TechNews

Superfast Fluorescence Sets New Speed Record

A nanoscale view of the new superfast fluorescent system using a transmission electron microscope. The silver cube is 75 nanometers wide. The quantum dots (red) are sandwiched between the silver cube and a thin gold foil.

Researchers at Duke University say they have developed a plasmonic device that can flip on and off 90 billion times a second.

Credit: Duke Today

Duke University researchers say they have developed an ultrafast plasmonic device that can flip on and off 90 billion times a second and could form the basis of optical computing.

"We can now start to think about making fast-switching devices based on this research, so there's a lot of excitement about this demonstration," says Duke professor Maiken Mikkelsen.

The device works because when a laser shines on the surface of a silver cube, the free electrons on its surface begin to oscillate together in a wave. The oscillations create their own light, which reacts again with the free electrons. The energy trapped on the surface of the nanocube, called a plasmon, creates an intense electromagnetic field between the silver nanocube and a thin sheet of gold. The field interacts with quantum dots that are sandwiched between the nanocube and the gold. The quantum dots then produce a directional, efficient emission of photons that can be turned on and off at more than 90 gigahertz.

"The eventual goal is to integrate our technology into a device that can be excited either optically or electrically," says Duke post-doctoral researcher Thang Hoang.

From Duke Today
View Full Article

Abstracts Copyright © 2015 Information Inc., Bethesda, Maryland, USA


No entries found

Sign In for Full Access
» Forgot Password? » Create an ACM Web Account