Getting a good vibe

Getting a good vibe

The slightest movement can ruin a photonics experiment. For Robert Boyd and his team, working in new labs designed to dampen vibration will make their job a whole lot easier.
September 30, 2014

Ask Robert Boyd why he is looking forward to working in the Advanced Research Complex (ARC) and he starts to talk about vibration. Not the vibrations caused by jackhammers or rumbling trucks, but the more subtle variety that human senses cannot detect. They pose a problem that he and his colleagues have repeatedly confronted in their former laboratories in the SITE building, home of the School of Electrical Engineering and Computer Science.

“If a mirror wobbles, a beam of light winds up at the wrong place,” explains Boyd, who holds the Canada Excellence Research Chair in Quantum Nonlinear Optics. Misdirected light, he adds, will undo the delicate task of interferometry, which involves bouncing and filtering intense laser light in ways that might be applied to transmitting or storing bits of data.

This kind of work is the essence of photonics — the science of light — where researchers operate on large tables arranged with devices that look like a high-tech version of a pinball machine. Light is sent down various channels, split in different directions, and forced to negotiate lenses or gratings that can reduce its speed from the fastest in the universe to an almost dead stop. All of these interactions hinge on precise detail, so much so that unplanned movements in the order of millionths of a metre can be enough to ruin an experiment.

“The measurements that you make will be unreliable, essentially garbage,” says Boyd. “It’s not just a little bit deficient, but useless. The signal you’re trying to measure is buried in the noise.”

What he calls “noise” is actually vibration, which was hard to avoid in the SITE building. While this structure successfully accommodates most researchers in computer science and electrical engineering, it simply was not designed to meet the exacting needs of photonics experiments. ARC, on the other hand, has been erected specifically for the challenges of vibration; its architecture features deeply rooted foundational piles that should eliminate the difficulties Boyd and his colleagues have been experiencing.

“Everything’s going to be 10 times easier,” he predicts, based on what he has witnessed at Université Laval, where a similarly designed building is being used for photonics research.

Apart from the physical benefits of the new complex, Boyd also foresees some administrative advantages that will result from moving to this new setting.

“Photonics is 50 percent physics and 50 percent engineering,” he says, noting that the multidisciplinary nature of the field usually means people are scattered in a number of locations on any given university campus. “The advantage here is that all of the photonics people will be in the same building.”

He anticipates that this arrangement should be cost-effective and efficient, since some of the most sophisticated — and expensive — research tools can be shared. Just as important, though, is the efficiency of the scientific process that drives those tools, which is bound to benefit from having researchers gathered under the same roof.

This story originally appeared in the summer 2014 issue of Research Perspectives, a publication of the University of Ottawa.

MAIN IMAGE: Robert Boyd demonstrates a laser projection of the University of Ottawa logo created by diffracting a laser beam off a computer-generated hologram.  Credit: Peter Thornton, uOttawa