The CSIR’s National Laser Centre has created what it calls the world’s first digital laser. South African scientists working at the centre have created a means of controlling a laser beam’s shape digitally and they claim the implications for health care, manufacturing, communications and other industries could be enormous.
Laser devices traditionally consist of mirrors, light and a casing containing a material such as crystal or glass. The material changes the frequency of the light to create a laser beam.
In conventional lasers, the shape of the beam is either left uncontrolled or is forced into a specific shape using costly optics. For example, surgical lasers are used for precision cutting.
The digital laser uses a “spatial light modulator” — it has a liquid crystal display (LCD) that can be “digitally addressed” with grayscale images that alter the beam.
Andrew Forbes, who leads the project at the NLC, says the digital laser uses the LCD as one of its mirrors and this is fitted at one end of the laser cavity. Because the LCD serves as a mirror, changing the image it displays changes the shape of the laser beam that is emitted.
This allows for digital control of the beam in real time, prompting the name “digital laser”. According to Forbes, this could have huge implications for many of the industries in which laser technology plays a role.
“Virtually any laser mode can be created with the digital laser,” Forbes says. “We can use one laser and a single beam shape to create multiple shapes of lights and resultant images. Previously, you would need a separate laser for each shape.”
Forbes says that now all it costs is a student’s time. “And students are very cheap,” he quips.
Fittingly, the project came about because of the work of a student, Sandile Ngcobo, a PhD candidate from the University of KwaZulu-Natal’s school of physics and research scientist at the CSIR. Ngcobo, along with Forbes, Liesl Burger and Igor Litvin published a paper detailing their work published in January.
As for the possible uses of the digital laser, Forbes says he and his team don’t yet know what it might be applied to. “However, we think it’s a disruptive technology.”
He sees possible applications in devices, health, communication and manufacturing. “To date, drilling different patterns means directing the round laser beam around a pattern, but now you could turn the beam into the pattern.”
The laser could also find use in communication. “People are talking about using the shapes of light to increase the bandwidth of communications,” Forbes says. “The digital laser might be one of the solutions to packing data into patterns of light and passing it down fibre optics.”
The CSIR owns the intellectual property that accompanies the digital laser and is trying to decide whether to spin it off into a standalone company or roll it into another, related technology.
“We have spoken to prospective investors, but it’s still very early days,” Forbes says.
Work on the digital laser grew out of a CSIR research project from three years ago, according to Forbes. “That’s the nature of science — you invest for a short time but may only see the outcome years later.”
Science & technology minister Derek Hanekom says he is “always careful about using the word ‘breakthrough’”, but that in this instance it is appropriate. “When we talk about an advance in laser technology, we’re talking about a technology that has a vast range of possible applications.” — (c) 2013 NewsCentral Media
