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 Tangled magnetic fields power cosmic particle accelerators
14.12.2018 | DOE/SLAC National Accelerator Laboratory

nachricht In search of missing worlds, Hubble finds a fast evaporating exoplanet
14.12.2018 | 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: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>