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2017 Issue 3: Science on a small scale

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Light matter / nanophotonics: studying light on a very small scale

Light matter / nanophotonics: studying light on a very small scale

Physicists Steve Hughes and Nishan Singh Mann explore how light interacts with objects on a very small scale.

[Nishan Singh Mann and Stephen Hughes]
Photo by Bernard Clark

With the world’s attention on Queen’s physicist Dr. Art McDonald after he received the Nobel Prize in Physics for breakthrough neutrino research, we decided to shine a spotlight on other innovative Queen’s physicists. Read more – and find links to all our physics research profiles – in The Biggest, Deepest Questions.


Very much at the theoretical level, Professor Stephen Hughes and PhD student Nishan Singh Mann study light matter interactions – the science of optics, and how light interacts with very small structures on the nano-scale. Their research has many applications, from next-generation quantum light sources for quantum computers to biosensors and high-efficiency solar cells.

"These are new nano-quantum technologies of the future that are going to be mainstream in probably 50 years," says Dr. Hughes, who believes that Mr. Singh Mann’s "killer" model – looking at disorder and non-linearities in photonic crystals – is going to have a huge impact across a number of sectors.

Stephen Hughes and Nishan Singh Mann

Stephen Hughes, Professor
Nishan Singh Mann, PhD Student
Queen's Department of Physics, Engineering Physics & Astronomy

Stephen Hughes: We study light matter interactions – the science of optics, and how light interacts with very small structures. The structures are typically on the nano-scale, where at least one of the length scales is a few hundred nanometres or less.

A nanometre is an extremely small size, about 1-50,000th the width of a human hair. Incredibly small, but these days, fabrication techniques have developed so much that they can reliably manufacture on that scale.

And most of what we look at is manufactured – semiconductor-type nano-structures that have applications in telecom, lasers, solar cells.

Our theory is to actually come up with structures that can stop light. The more you slow down light, the more you amplify it. And that takes you into the quantum world, and at the same time it basically enhances anything you’re trying to do in photonics, because you’re getting more bang for your buck.

Nishan Singh Mann: We are a theory group so our lab is a group of powerful computers.

For my PhD, I’m working on a model that combines disorder and non-linearities in photonic crystals – specifically, photonic crystal waveguides.

Disorder and non-linearities – previously, the community has looked at each of them in part. But when you look at them together, there is a feedback mechanism between the two, and I’m hoping it reveals some new, rich physical phenomena and allows us to explain some previous experiments that are done in the presence of disorder.

Stephen Hughes: A significant part of our research is done in direct collaboration with leading experimental groups throughout the world, including groups in Denmark, France, Germany, Canada and the U.S.

This close interaction also allows us to develop and improve our models and it is extremely rewarding to be able to explain complicated data, and predict entirely new experiments and see these measured in the lab, often years later.

To carry out a successful research program in academia, it is also important to attract a top quality team of outstanding graduate students and post-doctoral fellows, and so far at Queen’s I have been quite fortunate in this regard.

[Singh Mann and Hughes]
Nishan Singh Mann and Stephen Hughes (Photo by Bernard Clark)

thumbnail: Alumni Review coverOther feature research stories in the Queen's Alumni Review Physics Issue:

See also:

Photography: Bernard Clark  |  www.bernardclark.com  |  Bernard Clark on Facebook  |  Follow @phtogclark on Twitter

[cover graphic of Queen's Alumni Review, issue 1-2016]