Featured Research

from universities, journals, and other organizations

Built-in germanium lasers could make computer chips faster

Date:
September 10, 2012
Source:
Paul Scherrer Institut (PSI)
Summary:
Researchers have investigated how they could make the semiconductor germanium emit laser light. As a laser material, germanium together with silicon could form the basis for innovative computer chips in which information would be transferred partially in the form of light. This technology would revolutionize data streaming within chips and give a boost to the performance of electronics.

Peter Friedli and Hans Sigg preparing the experiment at the Infrared Beamline at the SLS for determining the laser properties of germanium.
Credit: Frank Reiser, Paul Scherrer Institut

Paul Scherrer Institute (PSI) researchers have investigated how they could make the semiconductor germanium emit laser light. As a laser material, germanium together with Silicon could form the basis for innovative computer chips in which information would be transferred partially in the form of light. This technology would revolutionise data streaming within chips and give a boost to the performance of electronics. The researchers have demonstrated that germanium must be put under strain by an external force in order to turn it into a laser material.

Related Articles


The decisive investigations were carried out by the scientists at the Swiss Light Source (SLS) at PSI and their results have recently appeared in the scientific journal Physical Review Letters. The research was supported by the Swiss National Science Foundation (SNSF).

In 1965, Gordon Moore proposed a law stating that the surface density of transistors in computer chips -- and consequently their computing power -- would double every two years. This law has proved to be valid since the beginning of the digital age; that is, since the introduction of the first integrated circuits for micro-processors, in 1960. However, in spite of the increasing number of transistors in computer chips, as well as other progress which has been made, the overall performance of processors has not been able to follow Moore's Law for the past decade, and specialists are now talking about 'Moore's Gap'. The reason for this is that modern chips have more cores -- individual processors -- that can only relatively slowly communicate with each other using current technology.

"Actually, we do know a way in which this gap can be closed. The key concept is "optical data transfer" between the different cores on the chip," explains Hans Sigg, a PSI scientist. "This means partially transferring information inside a chip with the aid of laser pulses, which would significantly speed up the information exchange." In order to do this, tiny lasers are needed which can be built into chips to send out light pulses. These, however, have so far not been available.

Tiny germanium lasers should make chips faster

Sigg's research team, together with colleagues from the ETH Zurich and the Politecnico di Milano, has now been able to demonstrate that germanium, under certain conditions, can function as a laser material. "Germanium lasers could make a break-through possible here, because germanium can be readily combined with Silicon, which is the basic material from which chips are made. Silicon itself cannot emit light and can hardly be combined with any available laser material," points out Sigg.

In their studies, which were performed at the Swiss Light Source (SLS) at PSI, the researchers investigated those properties of Germanium that are important for the generation of laser light, and compared them with those of currently available laser materials. "We stimulate the material by means of a powerful laser and simultaneously observe the changes occurring using infra-red radiation from the SLS," elucidates the doctoral student Peter Friedli, who carried out the decisive experiments together with scientist Lee Carroll. "To do this, we used the fact that these light pulses are only 100 picoseconds (i.e. 0.1 billionths of a second) long, allowing us to follow the relevant processes in the material; that is, the behaviour of electrons at different points in time."

Germanium must be deformed

"Our results are, on the one hand, encouraging, because germanium behaves similarly to traditional laser materials, and therefore the possibility of it emitting light cannot be excluded," says Sigg enthusiastically, "but with the limitation that the balance between amplification and loss is still so unfavourable in the germanium layers investigated so far that the material does not yet fulfil the condition for emitting laser light." But it has been demonstrated that this condition can be more closely approached the more the germanium is put under strain using an external force. The researchers hope to achieve the necessary conditions for the germanium in a follow-up project. For this, they will use a new technology that allows the strain to be greatly increased.

This research project has been supported by the Swiss National Science Foundation (SNSF).


Story Source:

The above story is based on materials provided by Paul Scherrer Institut (PSI). The original article was written by Paul Piwnicki. Note: Materials may be edited for content and length.


Journal References:

  1. Lee Carroll, Peter Friedli, Stefan Neuenschwander, Hans Sigg, Stefano Cecchi, Fabio Isa, Daniel Chrastina, Giovanni Isella, Yuriy Fedoryshyn, Jιrτme Faist. Direct-Gap Gain and Optical Absorption in Germanium Correlated to the Density of Photoexcited Carriers, Doping, and Strain. Physical Review Letters, 2012; 109 (5) DOI: 10.1103/PhysRevLett.109.057402
  2. Lee Carroll, Peter Friedli, Philippe Lerch, Jörg Schneider, Daniel Treyer, Stephan Hunziker, Stefan Stutz, Hans Sigg. Ultra-broadband infrared pump-probe spectroscopy using synchrotron radiation and a tuneable pump. Review of Scientific Instruments, 2011; 82 (6): 063101 DOI: 10.1063/1.3592332

Cite This Page:

Paul Scherrer Institut (PSI). "Built-in germanium lasers could make computer chips faster." ScienceDaily. ScienceDaily, 10 September 2012. <www.sciencedaily.com/releases/2012/09/120910082415.htm>.
Paul Scherrer Institut (PSI). (2012, September 10). Built-in germanium lasers could make computer chips faster. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2012/09/120910082415.htm
Paul Scherrer Institut (PSI). "Built-in germanium lasers could make computer chips faster." ScienceDaily. www.sciencedaily.com/releases/2012/09/120910082415.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