Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photonic wheels : for drag racing at nano scale

31.05.2013
Optical tweezers will soon be more agile than ever before since light beams can now induce a rolling movement onto a nanoscale object, in addition to pushing it along a surface.

Optical tweezers and spanners are about to become more sophisticated. A group of physicists in Germany has just demonstrated, for the first time, the existence of a novel, transverse effect pertaining to light beams used for optical trapping, called photonic wheel.


Photonic wheels : for drag racing at nano scale

This means that scientists will now have full rotational control over the micro- or nanoscale objects trapped in the tweezers’ optical beam. Peter Banzer and colleagues from the Max Planck Institute for the Science of Light, in Erlangen, Germany, just published their findings in the Journal of the European Optical Society Rapid Publications. The authors speculate that, under favourable low viscosity condition, this approach could lead to spinning a trapped particle that will then start moving like a spinning top, as soon as the trapping laser beam is switched off, thus creating the conditions for a nano drag race (see figure).

Due to their lack of mass, photons do not behave intuitively. Rather, they have characteristics of their own. They can be circularly polarised, for example. This means their electric field spins around the propagation axis—a characteristic described as angular momentum, which is parallel to the direction in which the photon travels. This longitudinal angular momentum is akin to that of aircraft propellers, aligned with the direction in which the aircraft travels.

Now, the authors have shown that photons can display purely transverse angular momentum, at a right angle to the direction in which they move. This is similar to the angular momentum of the spinning wheel of a bicycle, whereby the rotational axis is transverse to the direction of movement.

Banzer and colleagues first predicted the new capability theoretically. They then confirmed it through experimental work, using a highly focused light beam with a special polarisation. They used a single metallic nanoparticle to probe the beam in the focal plane. Since there is a measurable deformation of the beam shape in that plane, it proves the existence of a purely transverse angular momentum in the beam for the investigated scheme.

Combining this newly discovered photonic wheel with conventional beams gives full rotational control when manipulating particles. This opens the possibility of new applications such as nanomixers and micromachines in addition to application in quantum optics and nano-optics.

References
P. Banzer, M. Neugebauer, A. Aiello, C. Marquardt, N. Lindlein, T. Bauer and G. Leuchs, The photonic wheel - demonstration of a state of light with purely transverse angular momentum. J. Europ. Opt. Soc. Rap. Public. 8, 13032 (2013). [DOI: http://dx.doi.org/10.2971/jeos.2013.13032]
Weitere Informationen:
https://www.jeos.org/index.php/jeos_rp/article/view/13032/988
http://dx.doi.org/10.2971/jeos.2013.13032
http://www.mpl.mpg.de

Dr. Sabine König | Max-Planck-Institut
Further information:
http://www.mpl.mpg.de

More articles from Physics and Astronomy:

nachricht Mars 2020 mission to use smart methods to seek signs of past life
17.08.2017 | Goldschmidt Conference

nachricht Gold shines through properties of nano biosensors
17.08.2017 | American Institute of Physics

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>