UNSW FACULTY OF SCIENCE
MEDIA RELEASE 30 September 2009
Optical tweezers get a new light touch
Building the super-fast computers of the future has just become much easier thanks to an advance
by Australian researchers that lets them grab hold of tiny electronics components and probe their
inner structure using only a beam of light.
The discovery moves researchers a step closer to utilising semiconductor nano-wires that will be key
components of future integrated devices and circuits.
In a paper published in the journal Applied Physics Letters, a team led by Dr Peter Reece, from the
UNSW School of Physics, and colleagues from the Australian National University, report for the first
time that such tiny objects can not only be held by "optical tweezers" but simultaneously studied in
detail using a second laser beam.
"Optical tweezers work by focussing very intense laser beams that can impart forces onto very small
objects and let you physically push them around," says Dr Reece, a UNSW Vice-Chancellor's
Postdoctoral Research Fellow.
"Using one laser beam you can grab an object, turn it around and look at it from all angles and put it
into an orientation you're interested in. What we've done is bring in a second laser beam to probe
the internal structure of the object itself, using photo-luminescence spectroscopy.
"Every nano-wire - and, indeed any nano-scale object - is different and you need to understand
these nuances to make practical use of them. This gives us a new tool that we can use to pre-select
the components we want.
"The novel part of our work is to look at the light emitted from the nano-wire when it is excited with
the second laser beam as the diagnostic tool; it can tell us so much more about the nature and
structure of the material. No-one's done this before.
"I'm very interested in building nano-sized devices – it's a big new area of application in science.
While our demand for information processing grows unabated, our ability to meet these demands is
beginning to waiver.
"The microelectronics industry has reached its limits for providing further levels of large-scale
integration of components and, without a change in technology, future computer processor
performances will stagnate.
"The optical technologies that revolutionised long-haul communications and brought us high-speed
internet may be the key to the future of on-chip information processing. Working with researchers in
the UK, we hope we can harness the 'forces of light' to build and test prototype nano-scale optical
devices which may one day power your personal computer."
Media contacts:
Dr Peter Reece – Office 02 9385 5929 mobile 0423 117 969 p.reece@unsw.edu.au
UNSW Faculty of Science – Bob Beale 0411 705 435 bbeale@unsw.edu.au
NEWS 
