A team of scientists from the Institute for Photonics and Advance Sensing (IPAS) led by Dr. Shahraam Afshar have recently shown that optical fibres are more optically nonlinear than it was thought before. Through a fundamental study of optical nonlinear processes in optical fibres, Shahraam Afshar and his team have shown that the standard theories of nonlinear optical processes in waveguides have serious limitations when it comes to waveguides with sub-wavelength structures (nano-scale structures) made from high refractive index materials.

Theoretical simulation of a fibre mode

By developing a new and general theory of nonlinear optical processes, they have not only addressed these limitations but have also predicted new processes or effects that could have not been observed with the standard theories. The most important prediction of the new theory is that the light can be confined within an area twice smaller than fundamentally thought to be the minimum area. This results in higher light intensity, which in turn leads to higher nonlinearity of optical waveguides, which is described through a parameter called effective nonlinear coefficient.

Variation in the nonliear coefficent as a function of core diameter as perdicted by the different models. SM: Standard Model, ASM: , VNSE: , VNSE ORTH:

Afshar’s new theory predicts that the effective nonlinear coefficient of optical waveguides, can be factor 2 or more higher than what is expected according to the standard theory. Such prediction greatly affects the design and performance of nonlinear photonic devices. Utilizing the fabrication facility of IPAS, a newly formed institute led by Pro. Tanya Monro, the team has recently been successful to fabricate the world’s smallest core fibre with record nonlinear coefficient. Using these fibres Afshar’s team has recently confirmed experimentally the prediction of their new theory. The results of these fundamental theoretical and experimental breakthroughs have been published in prestigious journals and attracted a lot of interest among the experts in the field.

Experimental confirmation of the change in nonlinearity as a function of core diameter, as predicted by the new model.

The IPAS institute of the University of Adelaide has become a pioneer in establishing that:

The world is more nonlinear than we think

References

(1) S. Afshar V. and T. M. Monro, “ A full vectorial model for pulse propagation in emerging waveguides with subwavelength structurespart I:Kerr nonlinearity, ” Optics Express 17, 2298–2318 (2009).

(2) M. D. Turner, T. M. Monro and S. Afshar V., “ A full vectorial model for pulse propagation in emerging waveguides with subwavelength structures part II: Stimulated Raman Scattering, ” Optics Express 17, 11565–11581 (2009).

(3) S. Afshar V., W. Zhang and T. M. Monro, “ Experimental confirmation of a generalized definition of the effective nonlinear coefficient in emerging waveguides with subwavelength structures” CThBB6, CLEO Conference, Baltimore, USA (2009).

(4) T. M. Monro, W. Zhang, H. Ebendorff-Heiperiem, and S. Afshar V., “Emerging Nonlinear Optical Fibers: Revised Fundamentals, Fabrication and Access to Extreme Nonlinearity”, IEEE Journal of Quantum Electronics, Nov. Issue (2009)

(5) S. Afshar V., W. Zhang, H. Ebendorff-Heiperiem, and T. M. Monro, “Small core optical waveguides are more nonlinear than expected; Experimental confirmation”, Optics Letters, Accepted for publication.

Book Chapter:
(6) S. Afshar V., M. D. Turner and T. M. Monro, “Nonlinear optics in emerging waveguides: revised fundamentals and implications” in Supercontinuum Generation in Optical Fibers, edited by J. M.
Dudlley and J. R. Taylor, Cambridge University Press, under publication

The CoEP is now advertising for a position in fibre laser research. Applicants will need to have postdoctoral research experience in the experimental development of fibre lasers.

If this interests you, proceed to the job details and apply now for a fantastic oppurtinuty to be part of a leading research facility.

Deadline: 18 September 2009

This week the South Australian Minister for Science, the Honourable Micheal O’Brien MP, visited the University of Adelaide  and was given a short tour of the CoEP’s experimental facilities. These include state-of-the-art fibre and glass making facilities along with fibre characterisation labs.

Minister O’Brien was shown the glass and fibre fabrication approach and witnessed a live fibre draw – the process by which a macroscopic glass ‘preform’ is drawn down to a microscopic optical fibre.

Pictured left to right: Martyn Evans (Director, Community Engagement), Prof Tanya Monro, Minister O'Brien and Prof James McWha (Vice-Chancellor, University of Adelaide)

We hope the Minister enjoyed his visit and would like to thank him again for taking the time to tour our facilities.

The CoEP is currently advertising for a number of postdoctoral research posotions.

These offer oppurtunities in the key areas of optical fibre sensing and fibre lasers and will integrate with the recently formed new research institute, IPAS – the institute for Photonics & Advanced Sensing.

The deadline for applications is the 10th August 2009.

Australian Prime Minister, Kevin Rudd, today named Professor Tanya Monro as one of 10 emerging young Australian leaders.

From the Australian:

Mr Rudd spoke of the importance of leadership and presented awards to eight of the 10 winners, selected from 100 outstanding young Australians as part of The Weekend Australian Magazine’s Next 100: Emerging Leaders project .

Read the full article.

Prof Monro (pictured below) is the director of the CoEP and the soon-to-be-launched Institute of Photonics and Advanced sensing. Watch for extended interviews of the winners in this weekend’s Australian magazine.

Prof Tanya Monro (Picture courtesy: Kelly Barnes )

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Professor Tanya Monro was featured May 4, 2009 in the Australian as they showcased those investing their talents in science in their search for 100 young leaders.

Professor Tanya Monro, 36, Physicist

She’s been named one of the top 10 brightest young minds in Australia by science magazine Cosmos and says she knew at age 14 that she wanted to do a Phd in physics. Tanya Monro went on to do a Bachelor of Science (hons) at the University of Sydney, with honours (1st class) in physics, then her longed-for doctorate in physics, winning the Bragg Gold Medal for the best physics thesis in Australia. She then sorted through the offers and chose the Optoelectronics Research Centre at the University of Southampton, UK, where she remained for nearly seven years. Now based at Adelaide University where she is Director of the newly formed Institute for Photonics & Advanced Sensing, the Sydney-born Monro heads up the Centre of Expertise in Photonics where her research – into the field of science and technology that allows the generation and control of light using glass optical fibres – leads the world. The winner of the 2008 PM’s Prize for Physical Scientist of the Years says it was her physics teacher at school who inspired her. “He made me realise that physics is an elegant and powerful way of understanding our world. That is is not about remembering dry and isolated facts, but of constantly discovering how ideas fit together, and how often the more you learn, the simpler and more beautiful our world appears.”

The Defence Science and Technology Organisation (DSTO) has established a scholarship program with the University of Adelaide to encourage young scientists to pursue studies in Photonics and Optics, potentially leading to a career in defence research and development.

The program provides annual scholarships to assist Australian students in meeting their educational costs. The scholarships are awarded to students based on the results from their previous year of tertiary study, or their year 12 results in the case of the first year award.

The scholarship program is administered by the University of Adelaide on behalf of DSTO. The winners of the DSTO Scholarships for 2009 are:

1st Year

• Ms Sophie Hollitt
• Ms Georgia Mansell

2nd Year

• Mr Peter Edwards

3rd Year

• Ms Anna Perejma

4th Year

• Mr Nikita Simakov
• Mr Jonathan Boehm
• Mr Anthony Slattery

The CoEP congratulates all of the winners of the above scholarships.

The CoEP is pleased to announce that it will be hosting a seminar on Thursday the 9th of April given by Prof Phillip Russel. This event is a free public lecture and all are welcome.

Prof Russell is considered a ‘godfather’ of microstructured optical fibre research worldwide, and is known for giving quite insightful talks.

Currently he serves as the Director of the newly founded Max-Planck Institute for the Science of Light and Professor of Physics at the University of Erlangen-Nuremberg, Germany.  He obtained his PhD (1979) degree at the University of Oxford and has subsequently held positions in France, Germany, the USA and the UK.  He specializes in the behaviour of light in periodically structured materials and waveguides, and was the founder of BlazePhotonics Ltd (2001 to 2004) whose aim was the exploitation of photonic crystal fibre. Prof Russell is a Fellow of the Royal Society and the Optical Society of America and has won several international awards for his research.

The details of the talk are are given below, followed by the abstract.

Location: Kerr Grant theatre, Physics building, University of Adelaide.

Time: 6pm

Glass cages for catching light

In its most common form, photonic crystal fibre (PCF) consists of a hair-thin thread of glass with a ‘cage’ of tiny hollow channels running along its length. This periodic lattice makes it possible to guide light in new ways, for example, to cage it inside an empty core. In such a hollow-core PCF one is able for the first time to eliminate the diffraction of light over km distances in empty space. By filling the core with gases, nonlinear gas-laser interactions can be enhanced by seven orders of magnitude in the best low-loss PCFs. Hollow-core PCF can also be used, for example, to laser-guide small particles, molecules or atoms along a curved path. In PCFs with micron-sized solid-glass cores, the chromatic dispersion can be radically altered, which has led to a revolution in the brightness of broad-band white-light sources. The most recent example of such  supercontinuum” sources is nearly six orders of magnitude brighter than an incandescent lamp, yielding up to 10 mW/nm spectral intensity at visible and near IR wavelengths. The lattice of hollow channels also gives rise to phononic band gaps and families of multi-GHz guided acoustic modes, which themselves interact strongly with light, creating unusual forward and backward Brillouin spectra. By filling the hollow channels with metals such as silver or gold, one can explore plasmon resonances in arrays of parallel nanowires. Through its unique and varied characteristics, PCF is creating many new opportunities in diverse areas of fundamental and applied research.

The CoEP will soon be part of the new Institute for Photonics and Advanced Sensing (IPAS).  IPAS will be a transdisciplinary entity, building on the University of Adelaide’s leadership in photonics and optical fibre research. Federal funding of $28.8m will provide a new building to accommodate the rapid growth of IPAS.

As part of the expansion we are seeking persons in the roles of laboratory management and strategic development. Both positions represent an exciting oppurtunity to be part of a leading optical fibre research centre worldwide.

The CoEP hosted a Christmas function at the National Wine Centre on Friday 19 December.

A great time was had by all and Tanya said a few words on her vision for the new Institute.