Volume 5, Number 2

(This story also available in PDF format.)

McGill is an international research leader in an area that has broad implications  The photon is the fundamental physical particle of light, in the same way the electron is the fundamental particle of electricity. Just as electronics revolutionized our world during the past half-century, photonics – the application of light – is having a similar transformative impact on all aspects of our lives, from communications and health care to entertainment and sustainable energy.

Early diagnosis of debilitating disease, sustainable processes to generate solar energy and more effective, cost-efficient transmission of vast quantities of data all draw on the science of photonics. McGill researchers are leading the way in this increasingly important field of scientific discovery.

Applications for Telecommunications
Every day, millions of people access the Internet, send text messages, tweet, use smart phones or a GPS, download music, upload videos and play video games. Data transfer is thus growing exponentially every year, and the photon is the quintessential messenger in this process.

The wireless mobile phones, laptops and personal digital assistants that we all rely on are connected to the global optical fibre network that forms the backbone of our international telecommunications system. These optical fibres transmit signals over thousands of kilometres, across continents and under oceans. Each fibre carries tens of thousands of voice calls and data streams. One fibre can support more than 100 different wavelengths of light, each of which is switched on and off more than 10 billion times per second.

Increasingly, optical fibre links are being used over very short distances, too, within buildings and inside computer systems. The Department of Electrical and Computer Engineering at McGill hosts one of the largest groups of researchers in this field of any Canadian university. The group includes professors David Plant, James McGill Professor and NSERC/Bell Canada Industrial Research Chair in Ultra-high bit rate optical transport and networks, Lawrence Chen, Martin Rochette and Odile Liboiron-Ladouceur.

The cutting-edge researchers in the Photonics Systems group operate a shared laboratory infrastructure – valued at more than $15-million – that is the most advanced in Canada for ultrahigh bandwidth optical communications research.

Their work centres on solving problems that industry will face as optical communication bandwidths extend, from today’s maximum of 10 gigabits per second, to more than 100 gigabits per second. Specific areas of investigation include data modulation techniques, the design of advanced optical transmitters and modulators, all-optical signal processing approaches, impairments in signal transmission and designing advanced photonic integrated circuits that will incorporate multiple photonic devices into one chip.

The group also collaborates widely with many industrial partners, such as Bell Canada, Hydro- Québec, Reflex Photonics Inc. (a developer of high-speed optical connectivity) and CorActive High-Tech Inc. (a developer and manufacturer of advanced specialty optical fibre products).

Applications for Medicine
“Photonics also provides an exquisitely sensitive tool to probe biochemical reactions inside living organisms, cells and biological samples,” says Andrew Kirk, Associate Dean of Research and Graduate Education in the Faculty of Engineering. Photonic biosensors make use of the fact that very small changes in optical properties (such as reflectivity, absorption or fluorescence) can be measured with very high precision. Electrical and Computer Engineering professor Vamsy Chodavarapu, for example, makes use of fluorescent probes to measure changes in the oxygen level of neurons within the brain, allowing us to understand brain function with far greater accuracy.

In the same department, Kirk, a William Dawson Scholar, is developing integrated optical biosensors that can be used to provide early diagnosis of cancer, heart disease and other medical conditions. Both Chodavarapu and Kirk work closely with colleagues in the Faculty of Medicine to translate their research into clinical applications.

Several researchers in the Departments of Physics and Chemistry are also applying photonics to essential medical research, including professor Paul Wiseman (Physics and Chemistry), who recently developed a pioneering approach to the detection of malaria infection through the use of three-photon absorption spectroscopy; Chris Barrett (Chemistry), who is developing novel photo-functional surfaces for cell growth experiments, and David Burns (Chemistry), who is developing advanced spectroscopic instruments.

Applications for Sustainable Energy
All of the energy on this planet, with the exception of nuclear power, ultimately derives from the sun. As individuals, industry and governments recognize the need to move to sustainable power supplies, there has been a massive growth in interest in solar power and in particular in photovoltaic (PV) materials that convert sunlight into energy. The best-known PV material is the silicon solar cell, but silicon is inefficient and also expensive.

Many Faculty of Engineering researchers are seeking to develop alternatives that will work more effectively to solve the world’s energy problems:

  • Electrical and Computer Engineering professor Zetian Mi, a Hydro-Québec NanoEngineering Faculty Scholar, uses molecular growth techniques to create highly efficient multilayer PV materials;
  • Mining and Materials Engineering professor Nate Quitoriano grows silicon nanowires that promise to be much cheaper and more efficient than flat silicon cells;
  • Electrical and Computer Engineering professor Ishiang Shih is developing new compound semiconductor materials;
  • Mining and Materials Engineering professor George Demopoulos is developing nanostructured electrodes for solar cells.

This talented group of interdisciplinary specialists is working to solve some of the most pressing problems that prevent wide-scale adoption of low cost and sustainable solar power.

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