Optical fibres are the backbone of the internet, carrying vast amounts of data across cities, countries and oceans. Without them global communication would be more expensive and much slower.
Tanya Monro’s research has contributed to their performance. But she thinks that optical fibres can do much, much more for humanity. She’s dreaming of aircraft that know when they’re getting metal fatigue; water plants that react within seconds of cryptosporidium entering the water supply; tractors that know how much fertiliser every metre of the field needs; and wearable sensors that detect certain proteins or viruses.
At 35 years of age, this mother of three leads a team of over 20 researchers at the Centre of Expertise in Photonics at the University of Adelaide. She and her colleagues have created a new class of optical fibre using soft glass. These holey optical fibres have thousands of potential applications in industry, health, agriculture and defence.
For her leadership in photonics Tanya Monro receives the 2008 Malcolm McIntosh Prize for Physical Scientist of the Year.
In Tanya’s earlier years, however, it appeared that it would be sound waves, not light rays, which would guide her career.
An accomplished cello player and pianist, Tanya was keen to attend Sydney’s Conservatorium High School at age 12. But her mother wanted Tanya to keep her science options open and stay at a mainstream school. That decision reaped dividends for Australian science.
In year 9, Tanya’s science teacher at SCEGGS Darlinghurst in Sydney sparked her passion for physics. “He showed me that physics and mathematics provide an elegant and powerful way of understanding our world without simply remembering isolated facts. By fifteen I’d decided that I wanted to do a physics PhD,” says Tanya.
At first she was drawn to astrophysics. But, after her first year at The University of Sydney, Tanya took a summer job in photonics: understanding and controlling light. She was captivated by the subject and went on to specialise in it for her PhD. Her talent was quickly recognised and she was awarded the Bragg Gold Medal for the best physics PhD in Australia in 1998.
Her next move was to the University of Southampton in the UK, where she joined a team of some 180 researchers who had been responsible for many of the breakthroughs that enabled the creation of the optical fibre backbone to the internet. These thin silica glass fibres carry terabytes of data around the world; everything from phone calls to banking transactions to scientific data and Facebook updates.
Optical fibres work because there are two different layers of glass. The inner glass core is denser than the surrounding glass sheath. The light travels along the inner glass core reflecting off the outer glass sheath.
Silica glass is perfect for the job: put lots of light in one end and it emerges relatively unchanged. And it is possible to create two layers of glass that are chemically, thermally and optically compatible.
But when light travels over long distances in optical fibres, the signal has to be regenerated or cleaned up electronically. It would be much more efficient if you could process the signal optically.
Tanya realised that by introducing air holes, or tunnels, within the fibre, it is possible to concentrate the light guided by the fibre within a much smaller area, thus increasing the light intensity. She and her team went on to demonstrate that it is possible to process and regenerate photonic data signals using light itself, simply by passing them through a few metres of this new type of fibre. Her work opened the way to using new kinds of glass-known as ‘soft glasses’ because of their lower melting points-and bypassing some of the limitations of silica glass.
Glasses can be made from many materials including silicates, phosphates and fluorides but, until Tanya’s discovery, finding two compatible glasses to form the layers of an optical fibre was a somewhat hit and miss affair.
“I realised that by using holes to form the cladding of the fibre rather than a second material, I could create optical fibres from almost any kind of glass,” she says. “And that allows us to choose the right glass for each application and translate it into optical fibre form.” The applications are almost endless: each glass has distinct properties and different patterns of holes manipulate the light in different ways. In some fibres the light travels through the glass, in others it travels through the holes.
Silica glass, for example, is not transparent for mid-infrared wavelengths. “We’ve made optical fibres that can transmit this infrared light. These new fibres will protect aircraft from attack from infrared-controlled missiles; facilitate improved surgical procedures using infrared laser light; and detect gases in trace quantities.”
Some of the most exciting applications of these optical fibres are in diagnostics. “These fibres offer a tantalising opportunity to detect chemicals or biomolecules in-situ and in real time.” Tanya and her team have shown that this can be done by introducing coatings to the internal surfaces of the holes within the fibres. For example, by attaching antibodies within the fibre, specific biomolecules can be detected using light. If a target protein or virus is detected, the antibodies will fluoresce and the fibre will deliver the fluorescent light directly to a sensitive detector.”
“Ultimately, we would like to create sensors that could be used at the point of care to detect viruses such as flu viruses or HIV.”
Tanya and her colleagues are working with the Defence Science and Technology Organisation and a number of Australian companies to turn these ideas into reality.
1998 Doctor of Philosophy in physics, The University of Sydney
1995 Bachelor of Science with Honours (1st class) in physics, The University of Sydney
2005-present Professor of Photonics and Director, Centre of Expertise in Photonics, School of Chemistry and Physics, University of Adelaide
2003-2005 Royal Society University Research Fellow and Reader, Optoelectronics Research Centre, Southampton University, UK
2000-2003 Royal Society University Research Fellow and Principal Research Fellow, Optoelectronics Research Centre, Southampton University, UK
1998-2000 Research Fellow, Optoelectronics Research Centre, Southampton University, UK
Awards and fellowships
2008 Federation Fellowship
2007-2008 Australian Institute of Physics’ Women in Physics Lecturer
2007 Rising Star Award (South Australia’s ‘Top 50′ across all fields under the age of 35)
2007 Finalist, South Australian Scientist of the Year
2006 Cosmos magazine ‘Bright Spark’ award (Australia’s ‘Top 10′ scientific minds under 45)
2000 Royal Society University Research Fellowship, UK
1999 Bragg Gold Medal for the best physics PhD thesis in Australia in 1998
Memberships and appointments
2008 Founding member of the Advisory Committee for the Royal Institution, Australia
2008 Member of the community consultation panel for the Defence White Paper
2005 Member of the South Australian Premier’s Science and Research Council
1. Monro,T.M., Richardson,D.J., Broderick, N.G.R. and Bennett, P.J. Holey fibres: an efficient modal model. Journal of Lightwave Technology 17, 1093-1102, 1999.
2. Monro, T.M., Moss, D., Bazylenko, M., de Sterke, C.M. and Poladian, L., Observation of self-trapping of light in a self-written channel in a photosensitive glass. Physical Review Letters 80, 4072-4075, 1998.
3. Afshar V., S., Warren-Smith, S.C. and Monro, T.M. Enhancement of fluorescence-based sensing using microstructured optical fibres Optics Express 15, 17891-17901, 2007.
4. Ebendorff-Heidepriem, H. and Monro, T.M. Extrusion of complex preforms for microstructured optical fibers. Optics Express 15, 15086-15092, 2007.
5. Monro, T.M. and Ebendorff-Heidepriem, H. Progress in microstructured optical fibres. Annual Review of Materials Research 36, 467-495, 2006.