New device enables ultra-fast laser-beam steering

Researchers have developed a new device that can shape and steer beams of light at speeds never before achieved, paving the way for better optical devices such as holograms that can move rapidly in real time.
The new acousto-optic array consists of 64 tiny piezo-electric elements which act as high frequency loudspeakers.
The complex sound field generated deflects and sculpts any light passing through the new device. As the sound field changes, so does the shape of the light beam.
"This reconfigurability can happen extremely fast, limited only by the speed of the sound waves," said Bruce Drinkwater, Professor of Ultrasonics at the University of Bristol.

"The key advantage of this method is that it potentially offers very high refresh rates - millions of refreshes per second is now possible.
"This means that in the future laser beam-based devices will be able to be reconfigured much faster than is currently possible. Previously, the fastest achieved is a few thousand refreshes per second," said Drinkwater.

The advancement will enable reconfigurable lenses that can automatically compensate for aberrations allowing for improved microscopy and a new generation of optical tweezers that will make them more rapidly reconfigurable and so allow better shaped traps to be produced.
"What we have shown can be thought of as a form of optical holography where the hologram can be made in real time using sound," Dr Mike MacDonald, Head of the Biophotonics research group at the University of Dundee, said.

"The device can potentially be addressed much more quickly than existing holographic devices, such as spatial light modulators, and will also allow for much higher laser powers to be used," said MacDonald.
The capabilities of laser beam shaping and steering are crucial for many optical applications, such as optical manipulation and aberration correction in microscopy.
The study was published in the journal Optics Express.