australian physicists build reversible laser tractor beam
Last Updated : GMT 06:49:16
Arab Today, arab today
Arab Today, arab today
Last Updated : GMT 06:49:16
Arab Today, arab today

Australian physicists build reversible laser tractor beam

Arab Today, arab today

Arab Today, arab today Australian physicists build reversible laser tractor beam

The groundbreaking tractor beam
Canberra - XINHUA

Laser physicists in Australia have built a tractor beam that can repel and attract objects, using a hollow laser beam that is bright around the edges and dark in its center, the Australian National University (ANU) announced on Monday.
It is the first long-distance optical tractor beam and moved particles one fifth of a millimeter in diameter a distance of up to 20 centimeters, around 100 times further than previous experiments.
"Demonstration of a large scale laser beam like this is a kind of holy grail for laser physicists," said Professor Wieslaw Krolikowski, from ANU's Research School of Physics and Engineering.
The new technique is versatile because it requires only a single laser beam. It could be used, for example, in controlling atmospheric pollution or for the retrieval of tiny, delicate or dangerous particles for sampling.
The researchers can also imagine the effect being scaled up.
"Because lasers retain their beam quality for such long distances, this could work over meters. Our lab just was not big enough to show it," said co-author Dr Vladlen Shvedov, a driving force behind the ANU project, along with Dr Cyril Hnatovsky.
Unlike previous techniques, which used photon momentum to impart motion, the ANU tractor beam relies on the energy of the laser heating up the particles and the air around them. The ANU team demonstrated the effect on gold-coated hollow glass particles.
The particles are trapped in the dark center of the beam. Energy from the laser hits the particle and travels across its surface, where it is absorbed creating hotspots on the surface. Air particles colliding with the hotspots heat up and shoot away from the surface, which causes the particle to recoil, in the opposite direction.
To manipulate the particle, the team move the position of the hotspot by carefully controlling the polarization of the laser beam.
"We have devised a technique that can create unusual states of polarization in the doughnut shaped laser beam, such as star- shaped (axial) or ring polarized (azimuthal)," Dr Hnatovsky said
"We can move smoothly from one polarization to another and thereby stop the particle or reverse its direction at will."
The work is published in Nature Photonics.

arabstoday
arabstoday

Name *

E-mail *

Comment Title*

Comment *

: Characters Left

Mandatory *

Terms of use

Publishing Terms: Not to offend the author, or to persons or sanctities or attacking religions or divine self. And stay away from sectarian and racial incitement and insults.

I agree with the Terms of Use

Security Code*

australian physicists build reversible laser tractor beam australian physicists build reversible laser tractor beam

 



Name *

E-mail *

Comment Title*

Comment *

: Characters Left

Mandatory *

Terms of use

Publishing Terms: Not to offend the author, or to persons or sanctities or attacking religions or divine self. And stay away from sectarian and racial incitement and insults.

I agree with the Terms of Use

Security Code*

australian physicists build reversible laser tractor beam australian physicists build reversible laser tractor beam

 



GMT 13:23 2012 Saturday ,07 July

Syria shells Wadi Khaled: 3 killed, 9 wounded

GMT 17:45 2016 Monday ,18 April

School Olympics embody state's future vision

GMT 15:30 2017 Tuesday ,11 April

Church attacker denies his death

GMT 21:43 2012 Monday ,20 February

AUC remembers Omar Mohsen at the graduation

GMT 12:47 2017 Friday ,06 January

Daesh militants kill 4 soldiers near Iraq's Tikrit

GMT 21:13 2017 Monday ,06 February

UN: Afghan civilian casualties rose 3 percent in 2016

GMT 22:30 2014 Tuesday ,30 December

Jordanian senate passes income tax draft law

GMT 14:29 2016 Saturday ,29 October

Yuksel offers top-notch engineering services

GMT 02:36 2017 Friday ,03 February

Tunisian journalists executed, says Daesh suspect

GMT 10:32 2015 Saturday ,28 March

World's first 'Otaku' summit opens in Japan
Arab Today, arab today
 
 Arab Today Facebook,arab today facebook  Arab Today Twitter,arab today twitter Arab Today Rss,arab today rss  Arab Today Youtube,arab today youtube  Arab Today Youtube,arab today youtube

Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2025 ©

Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2025 ©

arabstoday arabstoday arabstoday arabstoday
arabstoday arabstoday arabstoday
arabstoday
بناية النخيل - رأس النبع _ خلف السفارة الفرنسية _بيروت - لبنان
arabstoday, Arabstoday, Arabstoday