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A world first: CSIR develops digital laser

By Greg Nicolson 19 September 2013

If President Jacob Zuma wants more positive news reports from South Africa he should look to the Council for Scientific and Industrial Research (CSIR) and its team who have made a revolutionary breakthrough in laser technology. GREG NICOLSON speaks to Professor Andrew Forbes and PhD candidate Sandile Ngcobo to find out what a “digital laser” is and the challenges they faced as they beat international competition to transform the laser industry.

Professor Forbes and his team had been trying to revolutionise laser technology for years. They wanted to create a device that would be simpler to use. Experts can spend a year or two trying to get the right beam in a laser for a specific purpose. Such a laser is only of use for that application. “My gut feel was it probably wouldn’t work,” said Forbes on Wednesday. Experts across the globe had tried to create a digital laser, which would be more efficient and effective, but had all failed.

Ngcobo, part of the CSIR’s Laser Centre team, took up the project with some pointers from his boss. “They kind of gave up because this thing really doesn’t work and a lot of people had actually tried to get the laser to work from different countries, everywhere. So a lot of people had given up on it, especially my supervisor,” said Ngcobo, a University of KwaZulu Natal PhD candidate under Forbes. “I was just doing the work. He wasn’t even aware I was doing this currently. He wasn’t keeping track,” he laughed.

But the South African team had advantages. They have one of the few labs in the world that specialises in both lasers and holograms, meaning they were well positioned to tackle the myriad of tiny technical challenges.

One day, Ngcobo walked into Forbes’s office and placed a graph on his desk. “The thing is I didn’t expect it to work and he did a fantastic job and when he brought this one particular graph inside my office I immediately realised this laser had worked this time and I knew that people all over the world had been trying to make it work. It really was an amazing graph to see, to realise that you’ve just re-invented a 50-year-old technology,” said Forbes.

Ngcobo described the reaction as “really, really happy”. What Forbes did, in fact, was yell, “Do you know what this means?” down the hallway.

Photo:  Professor Andrew Forbes and Sandile Ngcobo

At the public launch of the innovation on Tuesday, Science and Technology Minister Derek Hanekom lauded the digital laser as a coup for South Africa. Lasers are a multi-billion dollar industry. In medicine they are used for bloodless surgery, eye treatment and dentistry. In industry they help cut, weld, and make parts. In product development you’ll find lasers used to make printers, CDs, barcode scanners, thermometers and, of course, laser pointers.

Hanekom read a statement from Dr Igle Gledhill, President of the South African Institute of Physics: “This is what is often termed a breakthrough – and it is a real breakthrough. The digital laser opens up new visions of laser applications: and there are uses that we haven’t even thought of yet. In that way, it’s very much like just like the original invention of the laser over 50 years ago. Seeing world firsts come through from labs in South Africa is a joy shared across the scientific community, especially when young students are involved in this hands-on way.”

But it’s difficult to understand just what a digital laser is. Lasers have consisted of a box featuring two mirrors that bounce light before releasing it. The shape of the laser beam has, until now, been permanent, manipulated for each individual device. The digital laser uses an LCD screen, like a television, to replace one of the mirrors and project a specific image.

“So we teach this little television what to do if we give it a particular picture and what it should do to the light,” said Forbes. “And the result is that one of the mirrors in our laser is digital because it’s a liquid crystal television. You can show pictures to this television and every time we change the picture, the laser beam out of the laser changes. And that’s why we call it the digital laser. The big advantage is rather than design a new laser for every shape you want, you know only have to have one laser and just change the picture on your computer and you get a new device.”

Photo: Sandile Ngcobo

In his office, Ngcobo has a toy his children like to play with. The small laser projects an image of a soccer ball. There are many such applications where a laser produces a certain image because there is something in the device to project a specific shape of light.

Ngcobo explains: “What we’ve done is instead of having all these different objects in front of the laser or buying a new laser, basically with the kind of shape that you want, we have actually done away with the way we’ve done our laser. In the sense that now you can put in an LCD inside the laser and put a grayscale image like a hologram inside the laser and actually tell the LCD to display that kind of picture and the laser automatically understands that picture, what you want.

“If you want a square beam, you put in a picture inside the LCD of a square, depending on the shape calculations, and the laser will actually produce the shape that you want. It basically means that you can do different types of shapes of light, which always has proved the problem because some people spend a year or two years just to generate a specific shape. Now, it’s just that you have to have a picture of the laser beam that you want.”

The innovation is so important that Minister Hanekom compared the four-member CSIR team to other lauded South Africans such as Chris Barnard, Allan Cormack and Godfrey Housfield. He said the team would now be mentioned alongside Albert Einstein as contributors to the development of the laser. ProudlySA congratulated them for continuing the country’s history of world-firsts.

Forbes and Ngcobo were both modest when asked about the praise. In January next year, they will present their research to the global laser community for the first time at a conference in San Francisco (although it has already been published in the Nature Communications journal) which will be a barometer of their success. But there has already been a lot of interest around the world.

The next step is for the CSIR team to keep on improving their device, making it stronger and faster, and finalise the digital laser’s patent. Then they will partner with an organisation to produce an applied prototype. Within two to three years they hope the technology will start to feature in everyday devices.

But they’ve already overcome the biggest obstacle. “The major challenge was a mental barrier, actually, because if you’re trying to do something at the cutting edge and you don’t know that it actually can be done and you keep trying it and every time you try it it fails […] then it kind of keeps reinforcing what you believe, ‘Oh, this hasn’t been done because it’s not possible to do. Getting over that mental barrier was the most difficult thing, but we kept persevering,” said Forbes. DM

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Main photo: The image shows a myriad of laser beam shapes that were generated from the digital laser. No new optics or alignment was necessary to create these laser beams. In a traditional laser it would have been impossible to do this in one device, usually requiring a new device for each beam shape.

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