News Item

Optical Conveyor Belt

The American Institute of Physics News Update has featured an "optical conveyor belt". This work was done as a collaboration involving Prof Kishan Dholakia's research group in St Andrews and the group of Prof Pavel Zemanek at ISI in the Czech Republic.
Bessel Beam Pattern
Two optical fibres face each other, and high power laser beams emitted from these fibres counter-propagate and interfere with one another. These are not "normal" laser beams though, as they have been altered to have a very special variation in intensity across the beam that results in a narrow and non-diverging core to the beam. This is known as a "Bessel Beam". Small particles are trapped in this high-intensity core, and can be moved backwards and forwards in the resulting optical standing wave.

Kishan's collaborators at the Czech Academy of Sciences have a lovely animation of the optical conveyor belt on their website. The work was performed with Dr Vene Garces Chavez at St Andrews and Tomas Cizmar at ISI and is part of a EU collaborative project on optical trapping.

 

Kishan's Optical Trapping Research Group website

First posted BDS 13.5.05