Featured Research

from universities, journals, and other organizations

Nanoscale Lasers May Open Door To Faster Computers, More Reliable Internet Access

Date:
August 5, 2009
Source:
Arizona State University
Summary:
Engineers have found ways to make nanolasers smaller, opening up possibilities of integrating lasers more effectively with electronics components. Among results would be computers that operate more rapidly and efficiently, and quicker, more reliable Internet access.

Cun-Zheng Ning in his nanophotonics laboratory at ASU.
Credit: Copyright Arizona State University

We could soon see the potential of laser technology expand dramatically.

Ways to make lasers smaller are being discovered through collaborative efforts of researchers at Arizona State University and Technical University of Eindhoven in the Netherlands. The work opens up possibilities for using nanoscale lasers to significantly improve the performance of computers and speed up Internet access.

The teams' advances in breaking through previous limitations on how small lasers can be made are reported in a recent edition of the online science and engineering journal Optics Express.

Authors of the report include professor Martin Hill, who leads the Eindhoven team, and ASU team leader Cun-Zheng Ning, a professor in the School of Electrical, Computer and Energy Engineering in ASU's Ira A. Fulton Schools of Engineering.

Lasers once were the stuff largely of science fiction. Today they are everywhere in the world of electronics. They are essential components of CD and DVD players. They are used in the automatic check-out stations in supermarkets.

Small lasers are used in technology that enables communications across continents, and soon nanolasers will be used for communications between the parts inside your computer.

Engineers have been trying to make lasers smaller because it would enable the devices to be more effectively integrated with small electronics components. The more lasers that can be used with these components, the faster electronic devices could perform. This would do things such as speed up the workings of your computer and Internet access.

The size of lasers in any one dimension (for example, thickness) has been thought to be limited to one-half of the wavelength involved.

For instance, for lasers used in optical communications the required wavelength is about 1,500 nanometers, so a 750-nanometer laser was thought to be the smallest a laser could be made for optical communications.

In an optically denser medium such as a semiconductor, this limit is reduced by a factor of the index of refraction (expressed mathematically as ~3.0) of a semiconductor – in this case to about 250 nanometers.

The limit is sometimes called the diffraction limit, a property associated with any wave, such as a beam of light. Current theory says you can't make a laser smaller than this diffraction limit – or smaller than 250 nanometers for a semiconductor laser for communications devices.

The research teams at ASU and Eindhoven are showing there are ways around this supposed limit, Ning says.

One way is by the use of a combination of semiconductors and metals such as gold and silver.

"It turns out that the electrons excited in metals can help you confine a light in a laser to sizes smaller than that required by the diffraction limit," Ning explains. "Eventually, we were able to make a laser as thin as about one quarter of the wavelength or smaller, as opposed to one half."

Ning and Hill have achieved something like that by using a "metal-semiconductor-metal sandwich structure," in which the semiconductor is as thin as 80 nanometers and is sandwiched between 20-nanometer dielectric layers before putting metal layers on each side.

They have demonstrated that such a semiconductor/dielectric layer, thinner than the diffraction limit, and squeezed between metal layers, can actually emit laser light – a laser with the smallest thickness of any ever produced. The structure, however, has worked only in a low-temperature operating environment. The next step is to achieve the same laser light emission at room temperature.

Researchers worldwide are interested in integrating such metallic structures with semiconductors to produce smaller nanolasers because of the promise of applications for smaller lasers in a wide range of technologies.

"This is the first time that anyone has shown that this limit to the size of nanolasers can be broken," Ning says. "Beating this limit is significant. It opens up diverse possibilities for improving integrated communications devices, single molecule detection and medical imaging."

Nanoscale lasers can also be integrated with other biomedical diagnostic tools, making them work faster and more efficiently, he says.

These advances also represent a major step in nanophotonics – the study of the behavior of light on the nanometer scale and the ability to fabricate devices in nanoscale.

"Nanolasers can be used for many applications, but the most exciting possibilities are for communications on a central processing unit (CPU) of a computer chip," Ning says.

As computers get faster, the communication between different parts in a computer creates a processing bottleneck, he explains.

Since a signal can be transmitted between computer components much faster by a light wave emitted by a laser than by metal wires, optical communication (communication using light) is "the ultimate solution for improving on semiconductor chip communications," Ning says.

"But before this becomes a reality, lasers have to be made small enough to be integrated with small electronics components," he says. "This is why the Department of Defense and chip manufacturers such as Intel are working on optical solutions for on-chip communications."

Research in this field in the United States is being funded by the Defense Advanced Research Projects Agency (DARPA), the central research and development organization for the U.S. Department of Defense. The agency is supporting a collaborative team partnering researchers at ASU, the University of California at Berkeley and the University of Illinois, Urbana-Champaign.

ASU's collaboration with Hill's team at Eindhoven happened by coincidence, Ning says.

"We discovered we were working on the same problems and trying to achieve similar goals using similar ideas," he says. "So the partnership developed."


Story Source:

The above story is based on materials provided by Arizona State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Martin T. Hill, Milan Marell, Eunice S. P. Leong, Barry Smalbrugge, Youcai Zhu, Minghua Sun, Peter J. van Veldhoven, Erik Jan Geluk, Fouad Karouta, Yok-Siang Oei, Richard N๖tzel, Cun-Zheng Ning, and Meint K. Smit. Lasing in metal-insulator-metal sub-wavelength plasmonic waveguides. Optics Express, Vol. 17, Issue 13, pp. 11107-11112 DOI: 10.1364/OE.17.011107

Cite This Page:

Arizona State University. "Nanoscale Lasers May Open Door To Faster Computers, More Reliable Internet Access." ScienceDaily. ScienceDaily, 5 August 2009. <www.sciencedaily.com/releases/2009/07/090728132238.htm>.
Arizona State University. (2009, August 5). Nanoscale Lasers May Open Door To Faster Computers, More Reliable Internet Access. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2009/07/090728132238.htm
Arizona State University. "Nanoscale Lasers May Open Door To Faster Computers, More Reliable Internet Access." ScienceDaily. www.sciencedaily.com/releases/2009/07/090728132238.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) — If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) — Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) — British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury 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