Featured Research

from universities, journals, and other organizations

Seeing the light: Scientists bring plasmonic nanofields into focus

Date:
February 7, 2011
Source:
DOE/Lawrence Berkeley National Laboratory
Summary:
Scientists have engineered an innovative imaging technique to visualize plasmonic fields with nanoscale resolution. This technique, which harnesses light within a bowtie-shaped structure, could be used to measure the performance of plasmonic devices.

Scientists at Berkeley Lab’s Molecular Foundry have developed a web-based imaging toolkit designed for researchers studying plasmonic and photonic structures.
Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory

In typical plasmonic devices, electromagnetic waves crowd into tiny metal structures, concentrating energy into nanoscale dimensions. Due to coupling of electronics and photonics in these metal nanostructures, plasmonic devices could be harnessed for high-speed data transmission or ultrafast detector arrays. However, studying plasmonic fields in nanoscale devices presents a real roadblock for scientists, as examining these structures inherently alters their behavior.

"Whether you use a laser or a light bulb, the wavelength of light is still too large to study plasmonic fields in nanostructures. What's more, most tools used to study plasmonic fields will alter the field distribution -- the very behavior we hope to understand," says Jim Schuck, a staff scientist with Lawrence Berkeley National Laboratory (Berkeley Lab) who works in the Imaging and Manipulation of Nanostructures Facility at the Molecular Foundry.

Light microscopy plays a fundamental role in a scientist's repertoire: the technique is easy to use and doesn't inflict damage to a carefully crafted electronic circuit or delicate biological specimen. However, a typical nanoscale object of interest -- such as a strand of DNA or a quantum dot -- is well below the wavelength of visible light in size, which means the ability to distinguish one such object from another when they are closely spaced is lost. Scientists are now challenging this limit using 'localization' techniques, which count the number of photons emanating from an object to help determine its position.

In previous work, Schuck and colleagues at the Molecular Foundry, a U.S. Department of Energy (DOE) Nanoscale Science Research Centers, engineered bowtie-shaped plasmonic devices designed to capture, filter and steer light at the nanoscale. These nano-color sorter devices served as antennae to focus and sort light in tiny spaces to a desired set of colors or energies -- crucial for filters and other detectors.

In this latest advance, Schuck and his Berkeley Lab team used their innovative imaging concept to visualize plasmonic fields from these devices with nanoscale resolution. By imaging fluorescence from gold within the bowtie and maximizing the number of photons collected from their bowtie devices, the team was able to glean the position of plasmonic modes -- oscillations of charge that result in optical resonance -- just a few nanometers apart.

"We wondered whether there was a way to use light already present in our bowties -- localized photons -- to probe these fields and serve as a reporter," says Schuck. "Our technique is also sensitive to imperfections in the system, such as tiny structural flaws or size effects, suggesting we could use this technique to measure the performance of plasmonic devices in both research and development settings."

In parallel with Schuck's experimental findings, Jeff Neaton, Director of the Molecular Foundry 's Theory of Nanostructured Materials Facility and Alex McLeod, an undergraduate student working at the Foundry, developed a web-based toolkit, designed to calculate images of plasmonic devices with open-source software developed at Massachusetts Institute of Technology. For this study, the researchers simulated adjusting the structure of a double bowtie antenna by a few nanometers to study how changing the size and symmetry of a plasmonic antenna affects its optical properties.

"By shifting their structure by just a few nanometers, we can focus light at different positions inside the bowtie with remarkable certainty and predictability," said McLeod. "This work demonstrates that these nanoscale optical antennae resonate with light just as our simulations predict."

Useful for researchers studying plasmonic and photonic structures, this toolkit will be available for download on nanoHUB, a computational resource for nanoscience and technology created through the National Science Foundation's Network for Computational Nanotechnology.

"This work really exemplifies the very best of what the Molecular Foundry is about," said Neaton, who is also Acting Deputy Director of Berkeley Lab's Materials Sciences Division. "Three separate Foundry facilities -- Imaging, Nanofabrication and Theory -- collaborated on a significant advance in our understanding of how visible light can be localized, manipulated, and imaged at the nanoscale."

A paper reporting this research appears in Physical Review Letters and is available to subscribers online. Co-authoring the paper with Schuck, McLeod and Neaton were Alexander Weber-Bargioni, Zhaoyu Zhang, Scott Dhuey, Bruce Harteneck and Stefano Cabrini.

Portions of this work at the Molecular Foundry were supported by DOE's Office of Science. Support for this work was also provided by the National Science Foundation through the Network for Computational Nanotechnology.


Story Source:

The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jim Schuck et al. Non-perturbative visualization of nanoscale plasmonic field distributions via photon localization microscopy. Physical Review Letters, (in press)

Cite This Page:

DOE/Lawrence Berkeley National Laboratory. "Seeing the light: Scientists bring plasmonic nanofields into focus." ScienceDaily. ScienceDaily, 7 February 2011. <www.sciencedaily.com/releases/2011/02/110204092203.htm>.
DOE/Lawrence Berkeley National Laboratory. (2011, February 7). Seeing the light: Scientists bring plasmonic nanofields into focus. ScienceDaily. Retrieved July 26, 2014 from www.sciencedaily.com/releases/2011/02/110204092203.htm
DOE/Lawrence Berkeley National Laboratory. "Seeing the light: Scientists bring plasmonic nanofields into focus." ScienceDaily. www.sciencedaily.com/releases/2011/02/110204092203.htm (accessed July 26, 2014).

Share This




More Matter & Energy News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins