Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lasers in a flash

23.08.2010
Producing isolated laser pulses in just attoseconds made easier using a two-color laser field

Ultrafast time-resolved laser spectroscopy is a technique that uses the interaction of light with matter to study the properties of physical systems. Researchers can generate laser pulses lasting mere attoseconds—quintillionths of seconds—to examine the nuclear dynamics in different states of matter, including single atoms.

Generating isolated attosecond pulses reliably is challenging. Commonly, physicists use few-cycle laser pulses with a near infrared wavelength as a pump to temporarily ionize specific atoms, typically those of a noble gas. When an electron re-collides with a nucleus from which it has been pulled away, it emits light with a much higher frequency than the one in the pump laser. This so-called ‘high-order harmonic generation’ usually in the extreme ultraviolet region can create an attosecond pulse.

Eiji Takahashi and his colleagues at the RIKEN Advanced Science Institute in Wako, in collaboration with scientists at the Vienna University of Technology, Austria, have now reported a way to easily produce isolated attosecond pulses, which surpasses all previous attempts for simplicity and reliability1.

A number of research groups have recently generated isolated laser pulses as short as 80 attoseconds. However, their energy is still too low be used in practice, since the energy of the pump pulses is limited. High pump energy would induce high gas ionization such that the atoms hit by the pump pulses would be highly ionized, but this would prevent the whole process of re-collision. In addition, to guarantee reliable production of isolated attosecond pulses, the phase of the carrier envelope wave connected to the pump pulse needs to be stabilized, which requires an expensive and complicated process.

To circumvent these limitations, Takahashi and colleagues used a two-color laser field: a pump laser with an 800-nanometer wavelength superimposed on one of 1,300 nanometers. The combination of the two lasers allowed the generation of a higher harmonic spectrum without needing to stabilize the carrier envelope phase.

Crucially, they used conventional lasers that are readily available and inexpensive. “This novel two-color laser scheme also enables one to markedly suppress the detrimental gas target ionization,” notes Takahashi. “Consequently, not only the most appropriate phase-matching technique, but also an energy-scaling scheme, can be applied to produce intense isolated attosecond pulses.”

Takahashi also says that this method has the potential to produce isolated, attosecond, extreme-ultraviolet x-ray pulses with microjoule energy from a table-top system. He believes this would open the door to the realm of strongly nonlinear attosecond science.

The corresponding author for this highlight is based at the Extreme Photonics Research Group, RIKEN Advanced Science Institute.

1. Takahashi, E.J., Lan, P., Mücke, O.D., Nabekawa, Y. & Midorikawa, K. Infrared two-color multicycle laser-field synthesis for generating an intense attosecond pulse. Physical Review Letters 104, 233901 (2010).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6367
http://www.researchsea.com

More articles from Process Engineering:

nachricht Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>