17 September 2013
Researchers at South Africa’s Council for Scientific and Industrial Research (CSIR) have developed a world-first digital laser that could be a game-changer in the field, paving the way for new laser applications in areas ranging from medicine to communications.
A team based at the CSIR’s National Laser Centre has shown that, instead of resorting to expensive optics or other special mediating devices to control the shape of the light coming out of a laser, laser beams can be digitally controlled from within the laser device itself.
The team’s findings were published in the 2 August edition of the prestigious journal Nature Communications.
Announcing the breakthrough at media briefing in Pretoria on Tuesday, Science and Technology Minister Derek Hanekom said it was evidence of the country’s potential for scientific innovation.
“That the world’s first digital laser should come from our country is testimony to the calibre of scientists that South Africa has,” Hanekom said.
CSIR researcher Sandile Ngcobo, whose experimental work led to the breakthrough, said he believed the digital laser would prove to be a “disruptive” technology. “This is technology which may change the status quo and which could create new markets and value networks within the next few years or decade,” Ngcobo said in a statement.
Prof Andrew Forbes, who led the team of researchers, said the digital laser used a liquid crystal display (LCD) placed inside the laser. “Just as with LCD televisions, the LCD inside the laser can [digitally] be sent pictures to display. When the pictures change on the LCD inside, the properties of the laser beams that exit the device change accordingly,” Forbes said.
In a ground-breaking experiment at the CSIR’s laboratories in Pretoria, the team programmed the LCD to play a video of a selection of images representing a variety of desired laser modes. The result was that the laser output changed in real time from one mode shape to another.
“This is a significant advancement from the traditional approach to laser beam control, which requires costly optics and realignment of the laser device for every beam change,” Forbes said. “Since this is all done with pictures, the digital laser represents a paradigm shift for laser resonators.”
Laser technology already has widespread applications, in devices ranging from lighting displays to printers, DVD players, barcode scanners, surgical equipment and industrial cutters and welders.
“The dynamic control of laser modes could open up many future applications, from communications to medicine,” Forbes said. “Our device represents a new way of thinking about laser technology, and we see it as a new platform on which future technologies may be built.”
Forbes’ team included Ngcobo and fellow doctoral student Liesl Burger, and post-doctoral fellow Dr Igor Litvin.