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 New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>