Featured Research

from universities, journals, and other organizations

Nanotech discovery could lead to breakthrough in infrared satellite imaging technology

Date:
May 20, 2010
Source:
Rensselaer Polytechnic Institute
Summary:
Researchers have developed a new nanotechnology-based "microlens" that uses gold to boost the strength of infrared imaging and could lead to a new generation of ultra-powerful satellite cameras and night-vision devices. By leveraging the unique properties of nanoscale gold to "squeeze" light into tiny holes in the surface of the device, the researchers have doubled the detectivity of a quantum dot-based infrared detector.

Rensselaer Polytechnic Institute Professor Shan-Yu Lin has developed a new nanotechnology-based "microlens" that uses gold to boost the strength of infrared imaging and could lead to a new generation of ultra-powerful satellite cameras and night-vision devices. The device, pictured, leverages the unique properties of nanoscale gold to "squeeze" light into the tiny holes in its surface.
Credit: Image courtesy of Rensselaer Polytechnic Institute

Researchers from Rensselaer Polytechnic Institute have developed a new nanotechnology-based "microlens" that uses gold to boost the strength of infrared imaging and could lead to a new generation of ultra-powerful satellite cameras and night-vision devices.

Related Articles


By leveraging the unique properties of nanoscale gold to "squeeze" light into tiny holes in the surface of the device, the researchers have doubled the detectivity of a quantum dot-based infrared detector. With some refinements, the researchers expect this new technology should be able to enhance detectivity by up to 20 times.

This study is the first in more than a decade to demonstrate success in enhancing the signal of an infrared detector without also increasing the noise, said project leader Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university's Future Chips Constellation and Smart Lighting Engineering Research Center.

"Infrared detection is a big priority right now, as more effective infrared satellite imaging technology holds the potential to benefit everything from homeland security to monitoring climate change and deforestation," said Lin, who in 2008 created the world's darkest material as well as a coating for solar panels that absorbs 99.9 percent of light from nearly all angles.

"We have shown that you can use nanoscopic gold to focus the light entering an infrared detector, which in turn enhances the absorption of photons and also enhances the capacity of the embedded quantum dots to convert those photons into electrons. This kind of behavior has never been seen before," he said.

Results of the study were published online recently by the journal Nano Letters. The paper also will appear in a forthcoming issue of the journal's print edition. The U.S. Air Force Office of Scientific Research funded this study.

The detectivity of an infrared photodetector is determined by how much signal it receives, divided by the noise it receives. The current state-of-the art in photodetectors is based on mercury-cadmium-telluride (MCT) technology, which has a strong signal but faces several challenges including long exposure times for low-signal imaging. Lin said his new study creates a roadmap for developing quantum dot infrared photodetectors (QDIP) that can outperform MCTs, and bridge the innovation gap that has stunted the progress of infrared technology over the past decade.

The surface plasmon QDIPs are long, flat structures with countless tiny holes on the surface. The solid surface of the structure that Lin built is covered with about 50 nanometers -- or 50 billionths of a meter -- of gold. Each hole is about 1.6 microns -- or 1.6 millionths of a meter -- in diameter, and 1 micron deep. The holes are filled with quantum dots, which are nanoscale crystals with unique optical and semiconductor properties.

The interesting properties of the QDIP's gold surface help to focus incoming light directly into the microscale holes and effectively concentrate that light in the pool of quantum dots. This concentration strengthens the interaction between the trapped light and the quantum dots, and in turn strengthens the dots' ability to convert those photons into electrons. The end result is that Lin's device creates an electric field up to 400 percent stronger than the raw energy that enters the QDIP.

The effect is similar to what would result from covering each tiny hole on the QDIP with a lens, but without the extra weight, and minus the hassle and cost of installing and calibrating millions of microscopic lenses, Lin said.

Lin's team also demonstrated in the journal paper that the nanoscale layer of gold on the QDIP does not add any noise or negatively impact the device's response time. Lin plans to continue honing this new technology and use gold to boost the QDIP's detectivity, by both widening the diameter of the surface holes and more effective placement of the quantum dots.

"I think that, within a few years, we will be able to create a gold-based QDIP device with a 20-fold enhancement in signal from what we have today," Lin said. "It's a very reasonable goal, and could open up a whole new range of applications from better night-vision goggles for soldiers to more accurate medical imaging devices."

Co-authors of the paper are Rensselaer Senior Research Scientist James Bur, graduate student Chun-Chieh Chang, and Research Associate Yong-Sung Kim; Yagya D. Sharma, Rajeev V. Shenoi, and Sanjay Krishna of the Center for High Technology Materials at the University of New Mexico, Albuquerque; and Danhong Huang of the Space Vehicles Directorate at the Air Force Research Laboratory, Kirtland Air Force Base.


Story Source:

The above story is based on materials provided by Rensselaer Polytechnic Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Chun-Chieh Chang, Yagya D. Sharma, Yong-Sung Kim, Jim A. Bur, Rajeev V. Shenoi, Sanjay Krishna, Danhong Huang, Shawn-Yu Lin. A Surface Plasmon Enhanced Infrared Photodetector Based on InAs Quantum Dots. Nano Letters, 2010; 10 (5): 1704 DOI: 10.1021/nl100081j

Cite This Page:

Rensselaer Polytechnic Institute. "Nanotech discovery could lead to breakthrough in infrared satellite imaging technology." ScienceDaily. ScienceDaily, 20 May 2010. <www.sciencedaily.com/releases/2010/05/100518170220.htm>.
Rensselaer Polytechnic Institute. (2010, May 20). Nanotech discovery could lead to breakthrough in infrared satellite imaging technology. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2010/05/100518170220.htm
Rensselaer Polytechnic Institute. "Nanotech discovery could lead to breakthrough in infrared satellite imaging technology." ScienceDaily. www.sciencedaily.com/releases/2010/05/100518170220.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
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