Featured Research

from universities, journals, and other organizations

Nanostructures filter light to order

Date:
November 6, 2013
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
Arrays of nanoscale pillars made to reflect light of a selected color could find application as optical filters in digital cameras.

Altering the size and separation of these nanoscale mirrors changes the color of light that they reflect.
Credit: Copyright : 2013 A*STAR Institute of Materials Research and Engineering

Arrays of nanoscale pillars made to reflect light of a selected color could find application as optical filters in digital cameras.

A beam of sunlight is a mixture of different-colored light, including all the colors of the rainbow. Filtering or blocking a specific color, or colors, is often important in photography, color displays and other imaging techniques. An international team of engineers has now fabricated arrays of silver nanoscale pillars that can selectively reflect light of any desired color1. The team, led by Jinghua Teng and Yan Jun Liu at the A*STAR Institute of Materials Research and Engineering in Singapore, show that the color can be selected by varying the size of the pillars.

The stained glass in the windows of a church owes its color in part to an effect called surface plasmon resonance: light passing through the window interacts with electrons in the nanometer-sized metallic impurities that are trapped in the glass.

Light of a specific color, or wavelength, forces these electrons to quickly oscillate. In turn, the oscillating electrons enhance the amount of light transmitted through the glass at this wavelength. Teng, Liu and their co-workers were able to transfer this plasmonic effect from light-transmitting windows to light-reflecting mirrors. “Our compact reflectors could be used for applications including color coding, anti-counterfeiting and product branding,” says Teng.

The researchers deposited 6 nanometers of titanium, followed by 180 nanometers of silver on a quartz substrate. Onto the silver layer, they etched arrays of cylinders with diameters of 300 to 500 nanometers and a center-to-center separation of 320 to 540 nanometers (see image). The resulting gap between some of the pillars was as small as 20 nanometers. To achieve these tiny features, the team used a technique called electron-beam lithography: they scanned a beam of electrons to pattern the required features onto a protective layer placed on top of the silver. Then, they used a stream of charged ion atoms to mill the exposed metal and create the nanopillars.

After construction, Teng, Liu and their team shone white light onto each of the arrays and measured the wavelength of the reflected radiation. Arrays of cylinders of 500 nanometers in diameter and separated by 40 nanometers appeared red because they predominantly reflected light with a wavelength of 630 nanometers. Similarly, pillars with a diameter of 300 nanometers and a separation of 20 nanometers appeared blue as they reflected light with a 490-nanometer wavelength.

“We are now working to further develop this technique to create large-area color displays,” says Teng. “We also aim to develop applications and collaborations with industry.”


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Guangyuan Si, Yanhui Zhao, Jiangtao Lv, Mengqian Lu, Fengwen Wang, Hailong Liu, Ning Xiang, Tony Jun Huang, Aaron J. Danner, Jinghua Teng, Yan Jun Liu. Reflective plasmonic color filters based on lithographically patterned silver nanorod arrays. Nanoscale, 2013; 5 (14): 6243 DOI: 10.1039/C3NR01419C

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Nanostructures filter light to order." ScienceDaily. ScienceDaily, 6 November 2013. <www.sciencedaily.com/releases/2013/11/131106084432.htm>.
The Agency for Science, Technology and Research (A*STAR). (2013, November 6). Nanostructures filter light to order. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/11/131106084432.htm
The Agency for Science, Technology and Research (A*STAR). "Nanostructures filter light to order." ScienceDaily. www.sciencedaily.com/releases/2013/11/131106084432.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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