Featured Research

from universities, journals, and other organizations

Germanium is now laser compatible

Date:
April 22, 2013
Source:
ETH Zurich
Summary:
Good news for the computer industry: a team of researchers has managed to make germanium suitable for lasers. This could enable microprocessor components to communicate using light in future, which will make the computers of the future faster and more efficient.

Light emitting bridges of germanium can be used for communication between microprocessors.
Credit: Hans Sigg, PSI

Good news for the computer industry: a team of researchers has managed to make germanium suitable for lasers. This could enable microprocessor components to communicate using light in future, which will make the computers of the future faster and more efficient.

Related Articles


Researchers from ETH Zurich, the Paul Scherrer Institute (PSI) and the Politecnico di Milano have jointly developed a manufacturing technique to render the semiconductor germanium laser-compatible through high tensile strain. In their paper recently published in Nature Photonics, they reveal how they can generate the necessary tensile strain efficiently. The scientists demonstrate that they can use their method to effectively alter the optical properties of germanium, which is unsuitable for lasers as such: "With a strain of three per cent, the material emits around twenty-five times more photons than in a relaxed state," explains Martin Sess, a doctoral student at the Laboratory for Nanometallurgy headed by Ralph Spolenak and the EMEZ at ETH Zurich. "That's enough to build lasers with," adds his colleague Richard Geiger, a doctoral student at the Laboratory for Micro- and Nanotechnology at the PSI and the Institute for Quantum Electronics at ETH Zurich under Jrme Faist.

High tension through microbridges

In order to bring the germanium into a laser-compatible, stretched form with the new method, the researchers use the slight tension generated in germanium when it evaporates on silicon, strengthening this prestrain with so-called microbridges: they score exposed germanium strips, which remain attached to the silicon layer at both ends, in the middle on both sides. The two halves of the strip thus remain connected solely by an extremely narrow bridge, which is precisely where, for physical reasons, the strain of the germanium grows so intense that it becomes laser-compatible.

"The tensile strain exerted on the germanium is comparable to the force exerted on a pencil as two lorries pull upon it in opposite directions," says Hans Sigg, the project manager at the PSI, explaining the feat on a micrometre scale in everyday proportions. The material properties change because the individual atoms move apart a little through the expansion of the material, which enables the electrons to reach energy levels that are favourable for the generation of light particles, so-called photons.

Germanium laser for the computer of the future

The interdisciplinary research team's method could increase the performance of future computer generations considerably. After all, in order to improve computer performance, computer chips have constantly been made smaller and more densely packed. However, this approach will eventually hit a brick wall in the foreseeable future. "In order to increase performance and speed further, the individual components need to be linked more closely and communicate with each other more efficiently," explains Sess. This requires new transmission paths that are faster than today, where the signals are still transmitted via electricity and copper cables.

"The way to go in future is light," says Geiger. In order to be able to use this to transfer data, however, first of all light sources are needed that are so small as to fit onto a chip and react well to silicon, the base material of all computer chips. Silicon itself is not suitable for the construction of laser light, which is also the reason why it is so important for the researchers to make germanium laser-compatible: "Germanium is perfectly compatible with silicon and already used in the computer industry in the production of silicon chips," explains Geiger. If it is possible to build tiny lasers out of germanium using the new method, a system change is within reach. "We're on the right track," says Sess. The international team of researchers is currently in the process of actually constructing a germanium laser with the new method.


Story Source:

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


Journal Reference:

  1. M. J. Sess, R. Geiger, R. A. Minamisawa, G. Schiefler, J. Frigerio, D. Chrastina, G. Isella, R. Spolenak, J. Faist, H. Sigg. Analysis of enhanced light emission from highly strained germanium microbridges. Nature Photonics, 2013; DOI: 10.1038/nphoton.2013.67

Cite This Page:

ETH Zurich. "Germanium is now laser compatible." ScienceDaily. ScienceDaily, 22 April 2013. <www.sciencedaily.com/releases/2013/04/130422101151.htm>.
ETH Zurich. (2013, April 22). Germanium is now laser compatible. ScienceDaily. Retrieved January 25, 2015 from www.sciencedaily.com/releases/2013/04/130422101151.htm
ETH Zurich. "Germanium is now laser compatible." ScienceDaily. www.sciencedaily.com/releases/2013/04/130422101151.htm (accessed January 25, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, January 25, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NTSB: Missing Planes' Black Boxes Should Transmit Wirelessly

NTSB: Missing Planes' Black Boxes Should Transmit Wirelessly

Newsy (Jan. 23, 2015) In light of high-profile plane disappearances in the past year, the NTSB has called for changes to make finding missing aircraft easier. Video provided by Newsy
Powered by NewsLook.com
Iconic Metal Toy Meccano Goes Robotic

Iconic Metal Toy Meccano Goes Robotic

Reuters - Innovations Video Online (Jan. 22, 2015) Classic children&apos;s toy Meccano has gone digital, releasing a programmable kit robot that can be controlled by voice recognition. The toymakers say Meccanoid G15 KS is easy to use and is compatible with existing Meccano pieces. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
The VueXL From VX1 Immersive Smartphone Headset!

The VueXL From VX1 Immersive Smartphone Headset!

Rumble (Jan. 22, 2015) The VueXL from VX1 is a product that you install your smartphone in and with the magic of magnification lenses, enlarges your smartphones screen so that it&apos;s like looking at a big screen TV. Check it out! Video provided by Rumble
Powered by NewsLook.com
Analysis: NTSB Wants Better Black Boxes

Analysis: NTSB Wants Better Black Boxes

AP (Jan. 22, 2015) NTSB investigators recommended Thursday that long-distance passenger planes carry improved technology to allow them to be found more easily in a crash, as well as include enhanced cockpit recording technology. (Jan. 22) Video provided by AP
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