Featured Research

from universities, journals, and other organizations

Light bursts out of a flying mirror

Date:
April 23, 2013
Source:
Max Planck Institute of Quantum Optics
Summary:
Researchers have succeeded in generating flashes of extreme ultraviolet radiation via the reflection from a mirror that moves close to the speed of light.

Picture description: A laser pulse (red, bottom), liberates electrons (green) from the carbon atoms of a nanometer-thin foil and accelerates them to close to the speed of light. An infrared light pulse impinges on the electron layer from the opposite direction and reflects off the electron mirror as a light burst in the extreme ultraviolet with a duration of only a few hundred attoseconds.
Credit: Thorsten Naeser

An international team of researchers succeeds in generating flashes of extreme ultraviolet radiation via the reflection from a mirror that moves close to the speed of light.

A dense sheet of electrons accelerated to close to the speed of light can act as a tuneable mirror that can generate bursts of laser-like radiation in the short wavelength range via reflection. A team of physicists from the Max-Planck-Institute of Quantum Optics (MPQ) in Garching, the Ludwig-Maximilians-Universitδt (LMU) Mόnchen, the Queens University Belfast (QUB) and the Rutherford Appleton Laboratory (RAL) near Oxford created such a mirror in a recent experiment. The scientists used an intense laser pulse to accelerate a dense sheet of electrons from a nanometre-thin foil to close to the speed of light and reflected a counter-propagating laser pulse from this relativistic mirror. With this experiment, the physicists managed to carry out a Gedankenexperiment (thought experiment) formulated in 1905 by Albert Einstein stating that the reflection from a mirror moving close to the speed of light could in principle result in bright light pulses in the short wavelength range. The researchers report on their results in Nature Communications, 23. April, 2013.

In everyday life, reflections of light are usually observed from surfaces that are at rest such as the reflection from a piece of glass or a smooth surface of water. But, what happens if one creates a mirror moving incredibly fast, close to the speed of light? This question was answered more than a century ago by Albert Einsteins in 1905 in his theory of special relativity. Now, an international team of researchers investigated that question in an experiment.

In the experiment conducted at the Rutherford Appleton Laboratory near Oxford the physicists irradiated a nanometre-thin, freestanding foil with a 50 femtosecond short, ultra-intense laser pulse (one femtosecond is a millionth of a billionth of a second). The impinging laser pulse liberated electrons from the carbon atoms of the foil and rapidly accelerated to close to the speed of light in less than a micrometer forming a dense sheet of electrons capable of acting as a mirror. "This mirror structure is stable for only a few femtoseconds," explains Daniel Kiefer, who wrote his Dissertation on this topic. Within this extremely short life time the scientists shot a secondary laser pulse with a wavelength in the near infrared (800 nm) and a pulse duration of several femtoseconds from the opposite direction on the generated relativistic mirror structure.

In stark contrast to a mirror at rest, light reflected from a mirror that is moving is changed in its colour (that is in its wavelength) as the reflected photons gain momentum from the mirror. This process is very similar to a ball that bounces off a racket and thereby accelerates to higher speed. However, instead of moving faster (photons already travel at the speed of light), the reflected light is shifted in its frequency. This phenomenon is very similar to the Dopplereffect observed from an ambulance siren, which sounds higher (louder) or deeper (quieter) depending on whether the ambulance is moving towards or away from the observer. In the experiment, the incredibly high velocity of the electron mirror gave rise to a change in frequency upon reflection from the near infrared to the extreme ultraviolet up to a wavelength of 60 to 80 nanometre. Moreoever, the time duration of the reflected pulses was on the order of a few hundred attoseconds only (one attosecond is a billionth of a billionth of a second).

This experiment not only supports Albert Einstein's theory of special relativity, but in fact paves the way for a new method to generate intense, attosecond short flashes of light. Those pulses would allow the electron motion in atoms to be resolved thus giving deep insight into elementary processes in nature, which are so far largely unexplored.

For Prof. Schreiber and his group at the LMU, this is only the very beginning. Our laser systems will advance in the future delivering even more powerful pulses with higher repetition rate and shorter pulse duration. This scheme will benefit strongly from those developments in laser technology and thus may enable the generation of laser-like radiation with even higher intensity and shorter wavelength ideal to explore the microcosm. "The relativistic mirror has high potential in the next years," Schreiber concludes.


Story Source:

The above story is based on materials provided by Max Planck Institute of Quantum Optics. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Kiefer, M. Yeung, T. Dzelzainis, P.S. Foster, S.G. Rykovanov, C.LS. Lewis, R.S. Marjoribanks, H. Ruhl, D. Habs, J. Schreiber, M. Zepf, B. Dromey. Relativistic electron mirrors from nanoscale foils for coherent frequency upshift to the extreme ultraviolet. Nature Communications, 2013; 4: 1763 DOI: 10.1038/ncomms2775

Cite This Page:

Max Planck Institute of Quantum Optics. "Light bursts out of a flying mirror." ScienceDaily. ScienceDaily, 23 April 2013. <www.sciencedaily.com/releases/2013/04/130423134142.htm>.
Max Planck Institute of Quantum Optics. (2013, April 23). Light bursts out of a flying mirror. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2013/04/130423134142.htm
Max Planck Institute of Quantum Optics. "Light bursts out of a flying mirror." ScienceDaily. www.sciencedaily.com/releases/2013/04/130423134142.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) — The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) — The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) — President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) — Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
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:
from the past week

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