A switch for light-wave electronics
by Staff Writers
Munich, Germany (SPX) May 24, 2016
Light waves could in principle be used to drive future transistors. Since the electromagnetic waves of light oscillate approximately one million times in a billionth of a second, i.e. at petahertz (PHz) frequencies, optoelectronic computers could attain switching rates 100,000 times higher than current digital electronic systems.
However, to achieve this goal, we will need a better understanding of the sub-atomic electron motion induced by the ultrafast electric field of light.
Now a team led by Ferenc Krausz, who holds a Chair in Experimental Physics at LMU and is a Director of the Max Planck Institute for Quantum Optics in Garching, in collaboration with theorists from Tsukuba University in Japan, has used a novel combination of experimental and theoretical techniques, which for the first time provides direct access to the dynamics of this process. The new findings are reported in the journal Nature.
Insights into attosecond electron dynamics
The electric field of light changes its direction a trillion times per second and is able to mobilize electrons in solids at this rate.
This means that light waves can form the basis for future electronic switching, provided the induced electron motion and its influence on heat accumulation is precisely understood. In two papers published back-to-back in Nature in 2012, Krausz and his team had already shown that it is possible to manipulate the electronic properties of matter at optical frequencies (doi: 10.1038/nature11567, doi:10.1038/nature11720).
As in these earlier experiments, the researchers have now employed extremely intense laser pulses, each lasting for a few femtoseconds (1 fs is a millionth of a billionth of a second) to perturb electrons in glass (silicon dioxide).
The light pulse consists of a single oscillation of the field, so the electrons are moved left and right only once. The full temporal characterization of the light field after transmission through the thin glass plate for the first time yields direct insight into the electron dynamics induced by the light pulse in the solid on an attosecond scale.
Optimizing the interaction of light and matter
Since it is possible to measure the energy exchanged within one light cycle for the first time, the parameters of the light-matter interaction can be precisely determined and optimized for ultrafast signal processing.
The greater the degree of reversibility in the exchange and the smaller the amount of energy left behind in the medium after passage of the light pulse, the more suitable the interaction becomes for future light field-driven electronics.
To obtain a detailed understanding of the observed phenomena, and identify the most appropriate set of experimental parameters for that purpose, the experiments were backed up by a novel simulation method based on first principles developed at the Center for Computational Sciences at University of Tsukuba.
The theorists there used the K computer, currently the fourth fastest supercomputer in the world, to compute electron motions within solids with unprecedented accuracy.
The researchers succeeded in optimizing the energy consumption by carefully tuning the amplitude of the light field. At certain field strengths energy is transferred from the field to the solid during the first half of the pulse cycle and is almost completely re-emitted during in the second half of the oscillation period.
These findings confirm that a potential switching medium for future light-driven electronics would not overheat. The 'cool relationship' between glass and light might thus provide an opportunity to dramatically accelerate electronic signal- and data processing to its ultimate limits.
Computer Chip Architecture, Technology and Manufacture
Nano Technology News From SpaceMart.com
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.|