Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Solid-state photonics goes extreme ultraviolet

28.05.2015

Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.

In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to double its frequency, i.e., to change its colour from the visible to the ultraviolet, marking the advent of nonlinear optics and photonics.


Ultrafast lasers drive the motion of electrons inside silicon dioxide to generate extreme ultraviolet radiation.

(Graphic: Christian Hackenberger)

Now, researchers around Dr. Eleftherios Goulielmakis of the Attoelectronics Research Group at the Max Planck Institute of Quantum Optics in Garching, flashed an intense ultrashort laser pulse on thin films of the same material as in the mentioned pioneering experiment, and succeeded to convert laser light into radiation having a frequency more than 20 times higher than that of the laser, i.e., into the extreme ultraviolet range of the spectrum.

The laser pulses used comprised merely of a single oscillation of their wave cycle and allowed the scientists to drive the motion of electrons inside the crystal lattice extremely fast. As the electrons of the material bounced on the lattice potential formed by the atoms in the crystal, they radiate and thus convert the energy taken up by the laser light into extreme ultraviolet radiation. The experiments pave the way towards new solid-based photonic devices. Because the motion of the electrons driven by the laser pulse probes the properties of the solid, measurements of the emitted radiation lead to a deeper understanding of the structure and the inner workings of solids. (Nature, 28 May 2015)

Nonlinear optics and its wide range of modern applications in fundamental science, laser technology, telecommunications and medicine rely on the conversion of light from one colour to another, a process which takes place when an intense laser interacts with matter. Such processes allow one to generate laser-like radiation of frequencies (colour), which cannot be directly produced in lasers and hence to exploit it for new applications.

For more than two decades scientists have utilized very intense lasers to drive the motion of electrons in atoms or molecules in the gas phase such as to produce radiation in the extreme ultraviolet or even the x-ray part of the spectrum. “In condensed phase media — which comprise the basic pillar of modern fundamental and practical photonic applications — things are much more challenging”, says Goulielmakis, leader of the research group.

Solids cannot stand intense lasers without being damaged, and even worse, the fast vibrating atoms inside a solid randomly collide with the laser-driven electrons preventing the generation of coherent, laser-like radiation. By using extremely fast laser pulses (typically less than 2 femtoseconds) — so fast as to comprise only a single oscillation of a light wave generated by a “so-called” light field synthesizer — the MPQ scientists succeeded to sidestep these challenges. “Matter can stand intense field when illuminated for a very short time to produce extreme ultraviolet, and atoms merely move within this short time scale”, says Tran Trung Luu, scientist in the team.

But the MPQ scientists didn’t stop there. “We exploited the emitted EUV radiation to unveil information about the structure —more specifically the conduction band dispersion— of the solid which was earlier inaccessible to solid state-spectroscopies”, Goulielmakis points out. Being exposed to the optical fields the electrons get a kick from the valence band to the conduction band where they are accelerated by the laser field. “As the electrons move, they “feel” the surrounding structure of the solid, and this information is embodied in the emitted radiation”, says Manish Garg, a scientist in the team.

But how fast do electrons oscillate to produce extreme ultraviolet radiation in a solid? This is revealed by the frequency of the emitted radiation and the theoretical interpretation of the experiments. “We have a strong indication that the laser pulses force the electrons to perform extremely fast oscillations of tens of Petahertz (1015 Hz) frequencies inside the crystal,” Goulielmakis explains. “In fact, this is the fastest electric current ever generated in a solid, and the emitted radiation from these oscillations allow us to peer into the dynamics of this extremely fast motion.”

By manipulating the waveform of the laser pulses with the light field synthesizer, the scientists also succeeded to control these ultrafast electric currents inside the solid. “Our work opens up new routes for realizing light-based electronics operating at multi-PHz frequencies,” Dr. Goulielmakis resumes. [EG/OM]

Original publication:
T. T. Luu, M. Garg, S. Yu. Kruchinin, A. Moulet, M. Th. Hassan and E. Goulielmakis
Extreme Ultraviolet High-Harmonic Spectroscopy of Solids
Nature, 28 May, 2015, DOI: 10.1038/nature14456

Contact:
Dr. Eleftherios Goulielmakis
ERC Research Group Attoelectronics
Max Planck Institute of Quantum Optics
Laboratory for Attosecond Physics
Hans-Kopfermann-Str. 1, 85748 Garching, Germany
Phone: +49(0)89 / 32 905 -632 /Fax: -200
E-mail: Eleftherios.Goulielmakis@mpq.mpg.de
www.attoworld.de/goulielmakis-group

Dr. Olivia Meyer-Streng
Press & Public Relations
Max Planck Institute of Quantum Optics
Hans-Kopfermann-Straße 1, 85748 Garching, Germany
Phone: +49 (0)89 / 32 905 -213
E-mail: olivia.meyer-streng@mpq.mpg.de

Weitere Informationen:

http://www.mpq.mpg.de

Dr. Olivia Meyer-Streng | Max-Planck-Institut für Quantenoptik

More articles from Physics and Astronomy:

nachricht New manifestation of magnetic monopoles discovered
08.12.2017 | Institute of Science and Technology Austria

nachricht NASA's SuperTIGER balloon flies again to study heavy cosmic particles
07.12.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

Im Focus: A transistor of graphene nanoribbons

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."

Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

Making fuel out of thick air

08.12.2017 | Life Sciences

Rules for superconductivity mirrored in 'excitonic insulator'

08.12.2017 | Information Technology

Smartphone case offers blood glucose monitoring on the go

08.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>