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Particle Trapping and Particle Conveying w. 532nm laser "Tractor Beam, May2018"

Encap

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Particle Trapping and Particle Conveying w. 532nm laser "Tractor Beam, May2018"

In Star Trek, tractor beams are imagined to work by placing a target in the focus of a subspace/graviton interference pattern created by two beams from an emitter. When the beams are manipulated correctly the target is drawn along with the interference pattern. The target may be moved toward or away from the emitter by changing the polarity of the beams. Range of the beam affects the maximum mass that can be moved by the emitter, and the emitter subjects its anchoring structure to significant force.

Real world tractor beam? Maybe?

"Trapping and manipulation of particles using laser beams has become an important tool in diverse fields of research. In recent years, particular interest has been devoted to the problem of conveying optically trapped particles over extended distances either downstream or upstream of the direction of photon momentum flow. Here, we propose and experimentally demonstrate an optical analog of the famous Archimedes’ screw where the rotation of a helical-intensity beam is transferred to the axial motion of optically trapped micrometer-scale, airborne, carbon-based particles. With this optical screw, particles were easily conveyed with controlled velocity and direction, upstream or downstream of the optical flow, over a distance of half a centimeter. Our results offer a very simple optical conveyor that could be adapted to a wide range of optical trapping scenarios." ~
From: The Optical Society of America "Particle trapping and conveying using an optical Archimedes’ screw " May 2018, https://www.osapublishing.org/optica/fulltext.cfm?uri=optica-5-5-551&id=386023


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"Fig. 2. Optical Archimedes’ screw. (a) The Fourier domain mask that was applied to the phase-only SLM. (b) Calculation of beam profile in the focal plane at the middle of the cuvette. The arrows indicate dark volumes in which particles were observed to be trapped. (c) Beam profile captured on a camera, using a lens of a longer focal length than used for trapping, and scale-adjusted for the lens used for trapping. (d) Calculation of beam profile at several locations along the propagation length. (e) Simulation of several iso-intensity surfaces of the beam around the focal plane. (f) Simulations, for several rotation angles of the optical screw, of a plane cut [as shown in (e)] of the beam parallel to the optical axis and displaced transversely to the point indicated by one of the arrows on panel (b) above. The dashed white circles denote a possible trap location for the particle. The white arrows are a guide to the eye."
 
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Encap

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Re: 532nm Laser Particle Trapping and Conveying "Tractor Beam 2018"

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:can: :wave:
 
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lasersbee

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Re: Particle Trapping and Particle Conveying w. 532nm laser "Tractor Beam, May2018"

Interesting Stuff... More details than I had
pecviously. Thaks for posting.

Jerry
 

CurtisOliver

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Re: Particle Trapping and Particle Conveying w. 532nm laser "Tractor Beam, May2018"

Very interesting, thanks for sharing Encap. :beer:
 

paul1598419

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Re: Particle Trapping and Particle Conveying w. 532nm laser "Tractor Beam, May2018"

Yeah, this is all interesting stuff, but the tractor beam analogy is a bit far fetched. This works for carbon nano-particles and single red blood cells. I'm sure it would work for equally massive objects too. But, if you try doing it with something large enough to be seen with the naked eyes, the amount of power necessary to accomplish it would likely obliterate the object. Still good stuff, just without the hype. :D
 




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