Search Menu
Photonics Media Photonics Buyers' Guide Photonics Spectra BioPhotonics EuroPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook
More News

Optical Trapping Expands to 3-D

Facebook Twitter LinkedIn Email Comments
techTrapping1.jpgSince the mid-80s, optical tweezers have helped study the physics behind a myriad of microscopic phenomena ranging from DNA elasticity to micromachines. However, the effectively planar nature of the optical trapping effect -- a clear object being pushed toward the focal point of a laser beam -- has limited the vast majority of the investigations to two-dimensional force evaluations perpendicular to the laser beam.

Researchers from Instituto Nacional de Astrofisica in Puebla, Mexico, and St. Andrews University and Edinburgh University, both in the UK, have found that the interference pattern created by two Laguerre-Gaussian light beams can be used in an optical tweezers setup to create multiple trapping sites within the interference pattern. As reported in the May 10 issue of Science, they used the pattern to stack as many as 16 microscopic spheres in each of the sites, thus creating 3-D structures. By changing the frequency of one of the beams, they induced an angular Doppler effect that rotated the interference pattern, resulting in a rotation of the stack. 

Using these techniques, the researchers also have constructed asymmetrical 3-D structures of spheres, which they believe will be used someday to create predetermined nuclei for novel, self-assembled crystalline structures.

Photonics Spectra
Jul 2002
Research & TechnologyTech Pulse

back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2019 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA,

Photonics Media, Laurin Publishing
x Subscribe to Photonics Spectra magazine - FREE!
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.