Research & Other Activities

Welcome to my website which has links to my research and other activities.  An earlier google sites website can still be accessed here but this is no longer updated. If you want to follow me on Twitter, then you can follow me at @johnmdudley which is a great way to keep up to date with my various research and education activities.  At present, content of this website is only in English, but if you need any information in French, just ask (in French of course!)  


Source Development, Instabilities, Characterization and Control 

Femtosecond supercontinuum

I have been studying ultrafast lasers since my PhD, and the rich dynamics of laser physics continues to fascinate me. The recent development of advanced pulse measurement techniques such as the dispersive Fourier transform and the time lens afford characterization possibilities that were only dreamt of 2 decades ago.  The ability to perform real-time spectral and temporal characterization has opened up new possibilities to directly study the fundamental origins of ultrafast laser buildup and instability.  My  work in this area initially focussed on studies of supercontinuum noise and spectral correlations, but has recently expanded to explore open questions in mode-locked laser dynamics.  In fact, although the dynamics of mode-locked lasers have been studied since the very early days of laser physics, there are important and fundamental open questions regarding the operation and physics of dissipative soliton laser, when the laser operation is governed by not only gain and loss, but also dispersion and nonlinearity, and sometimes highly dissipative spectral filtering.  At the same time, the availability of convenient machine learning tools opens entirely new and potentially revolutionary approaches for analysis and control of pulsed laser operation and nonlinear propagation. This area of research is not only of fundamental interest, but also promises to set the scene for the next generation of fibre laser source.  

Selected Publications

M. Narhi, B. Wetzel, C. Billet, S.Toenger, T. Sylvestre, J.-M. Merolla, R. Morandotti, F. Dias, G. Genty, J. M. Dudley
Real-time measurements of spontaneous breathers and rogue wave events in optical fibre modulation instability
Nature Communications 7, 13675 (2016)

P. Ryczkowski, M. Närhi, C. Billet, J.-M. Merolla, G. Genty, J. M. Dudley, Real-time full-field characterization of transient dissipative soliton dynamics in a mode-locked laser, arXiv:1706.08571, Nature Photonics 12, 221-227 (2018).

M. Närhi, L. Salmela, J. Toivonen, C. Billet, J. M. Dudley, G. Genty, Machine learning analysis of extreme events in optical fibre modulation instability, Nature Communications 9 4923 (2018)

P. Ryczkowski, M. Närhi, C. Billet, J.-M. Merolla, G. Genty, J. M. Dudley, Seeing laser solitons born from chaos, Optics and Photonics News, Special issue on Optics in 2018 December (2018)

C. Lapre, C. Billet, F. Meng, P. Ryczkowski, T. Sylvestre, C. Finot, G. Genty, J. M. Dudley, Real-time characterization of spectral instabilities in a mode-locked fibre laser exhibiting soliton-similariton dynamics, Scientific Reports 9, 13950 (2019)

L. Salmela, C. Lapre, J. M. Dudley, G. Genty, Machine learning analysis of rogue solitons in supercontinuum generation, Scientific Reports 10, 9596 (2020)

F. Meng, J. M. Dudley, Toward a self-driving ultrafast fiber laser, Light: Science and Applications 9 26 (2020)

F. Meng, C. Lapre, C. Billet, G. Genty, J. M. Dudley, Instabilities in a dissipative soliton-similariton laser using a scalar iterative map, Optics Letters 45, 1232-1235 (2020)

Supercontinuum Physics

Femtosecond supercontinuum

A key area of my research since 2000 has focused on studying nonlinear propagation and supercontinuum generation in highly nonlinear and photonic crystal fibers (PCF). This work has involved experiments carried out by my own group in France, as well as analysis of results from a number of international groups.  Major results have included: first demonstration of PCF supercontinuum generation in the nanosecond regime using a compact microchip laser system; detailed numerical modeling of pulse propagation and supercontinuum generation in PCF in both the nanosecond and femtosecond regimes; definition of a quantitative measure of spectral coherence; use of the spectrogram representation to physically interpret the complex dynamics.  In 2006, I co-wrote the first major review of the field of PCF supercontinuum generation, but it should be remarked that this paper is far more than just a compilation of published results; we carried out many original numerical studies to illustrate previously unknown features of the dynamics, and to aid in experimental design.  In 2010, I co-edited a book with a selection of papers by experts that updated the supercontinuum state of the art.  I am currently working on extending the supercontinuum to new wavelength ranges and continuing studies of techniques for noise reduction, particularly in the mid-IR. This work has been funded by the Horizon 2020 ITN Project SUPUVIR.  

Selected Publications

J. M. Dudley, G. Genty, S. Coen, Supercontinuum Generation in Photonic Crystal Fiber,
Reviews of Modern Physics 78 1135-1184 (2006)

J. M. Dudley and J. R. Taylor, Ten years of nonlinear optics in photonic crystal fibre: progress and perspectives,
Nature Photonics 3 85-90 (2009)

J. M. Dudley and J. R. Taylor (Eds) Supercontinuum Generation in Optical Fiber, Cambridge University Press, 400 pages, ISBN 978-0521514804 (2010)

J. M. Dudley and G. Genty, Supercontinuum Light, Physics Today 66(7) 29-34 (2013)

E. Genier, P. Bowen, T. Sylvestre, J. M. Dudley, P. Moselund, O. Bang, Amplitude noise and coherence degradation of femtosecond supercontinuum generation in all-normal-dispersion fibers, Journal of the Optical Society of America B, 36 A161-167 (2019)

Rogue Waves

The importance of the supercontinuum as a technological light source motivated intense interest into its noise and stability properties which subsequently opened up a new field of research into optical rogue waves.  The idea here is that the instabilities observed on a light wave propagating in an optical medium are analogous to those that drive the emergence of giant waves on the surface of the ocean.  My work here has been carried out in the frame of an ANR grant MANUREVA and an ERC Advanced Co-Investigator Grant MULTIWAVE (with F Dias from UCD Dublin) where the aim was to study potential analogies between ocean waves and light waves carefully and in detail.  We took our time with MULTIWAVE to do things properly, as when we began our work there were all sorts of papers being rushed into print proposing analogies between ocean waves and optics in systems where no such analogy existed.  We like to think that the work in MULTIWAVE has led to some structure being introduced into this field. MULTIWAVE completed in 2016, but our work led to a number of significant results in the field of optical rogue waves, some of which were summarised in a 2014 paper paper in Nature Photonics.   I am currently working on developing new measurement techniques to provide new insights into the complex optical rogue wave dynamics, as well as to explore some new approaches to developing an even better understanding of the underlying physics.  Some key publications are listed below, including a significant 2019 review paper in Nature Reviews Physics that highlights the state of the art of rogue wave research in both oceanography and optics.  

Selected Publications

B. Kibler, J. Fatome, C. Finot, G. Millot, F. Dias, G. Genty, N. Akhmediev, J. M. Dudley.  The Peregrine soliton in nonlinear fibre optics Nature Physics 6, 790–795 (2010)

B. Kibler, J. Fatome, C. Finot, G. Millot, G. Genty, B. Wetzel, N. Akhmediev, F. Dias, J. M. Dudley, Observation of Kuznetsov-Ma soliton dynamics in optical fibre Scientific Reports  2 463 (2012)

J. M. Dudley, F. Dias, M. Erkintalo, G. Genty, Instabilities, Breathers and Rogue Waves in Optics.  Nature Photonics 8, 755-764 (2014)

J. M. Dudley, M. Erkintalo, G. Genty, Rogue Waves of Light, Optics and Photonics News, 26 (11) 34-41 (2015)

J. M. Dudley, G. Genty, A. Mussot, A. Chabchoub, F. Dias, Rogue waves and analogies in optics and oceanography, Nature Reviews Physics 1 675-689 (2019) and on arXiv (2019) 

Ultrafast accelerating beams, Material Processing, Other Topics

 I have a long-standing interest in ultrafast phenomena in optics, and have worked in areas which have included the development of picosecond and femtosecond sources and ultrafast measurement techniques (including frequency resolved optical gating FROG).  One major achievement in source development was the co-discovery of the "similariton" regime of optical fibre pulse propagation (a word that I simultaneously take credit and blame for inventing!) which used powerful techniques of the mathematics of self-similarity in nonlinear systems to describe a particular regime of fibre amplifier propagation which allowed pulsed fibre amplifier operation to be scaled to new power levels.  More recent work in this area at FEMTO-ST has been in support of the fantastic experiments being led by my colleague Francois Courvoisier (recently awarded an ERC Consolidator Grant) to develop unique and novel degrees of freedom for femtosecond laser ablation and materials processing through the use of so-called "nondiffracting" or "accelerating" beam structures.  

Selected Publications

J. M. Dudley, C. Finot, D. J. Richardson, G, Millot
Self Similarity in Ultrafast Nonlinear Optics Nature Physics 3 597-603 (2007).

L. Froehly, F. Courvoisier, A. Mathis, M. Jacquot, L. Furfaro, R. Giust, P.-A. Lacourt, J. M. Dudley
Arbitrary accelerating micron-scale caustic beams in two and three dimensions
Opt. Express, 19 16455-16465 (2011)

A. Mathis, L. Froehly, S. Toenger, F. Dias, G. Genty, J. M. Dudley, Caustics and Rogue Waves in an Optical Sea, Scientific Reports 5, Article number: 12822 10.1038/srep12822 (2015)

P. Ryczkowski, M. Barbier, A. T. Friberg, J. M. Dudley, G. Genty, Ghost imaging in the time domain
Nature Photonics 10, 167-170 (2016)

L. Froehly, F. Courvoisier, D. Brunner, L. Larger, F. Devaux, E. Lantz, J. M. Dudley, M. Jacquot, Advancing Fourier: space–time concepts in ultrafast optics, imaging, and photonic neural networks, Journal of the Optical Society of America A 36, C69-C77 (2019)

Outreach & Education

I have always been interested in developing effective means to communicate science to students and the general public. Over the years I have worked on demonstration-based teaching for liberal arts courses and the use of historical material in lectures, and you can look at some publications on these themes here.   I have also developed a live-science lecture spanning 2 hours with non-stop experiments on light and related areas of physics.  You can see an outline of what this involves here by following this Twitter thread.    

I have also worked often with professional societies such as EPS, SPIE, OSA and the IEEE, and I have devoted extensive efforts in public communication of science to initiating and then chairing The International Year of Light and Light-based Technologies 2015. 

The International Year of Light and Light-based Technologies 2015 (IYL 2015) was a United Nations observance that aimed to raise awareness of the achievements of light science and its applications, and its importance to humankind.  I first had the idea for an International Year around the theme of light back in 2009, but it took an enormous effort by many different partners under the leadership of UNESCO to bring things together.  The International year of light resulted in over 13,000 events in 147 countries during 2015, reaching out to an incredibly diverse audience from pre-schoolers to politicians.  IYL 2015 forged many new links and collaborations between decision makers, industry leaders, scientists, artists, social businesses, NGOs and the public at large,  and he estimated reach of all IYL 2015 activities worldwide was estimated to exceed 100 million.  To learn more, you can review the IYL2015 website, or download the IYL 2015 Final Report from this link.  You can also read about the story of how the IYL2015 was put together here.  

I was also privileged to be asked to coordinate the followup action which led to the proclamation of an annual United Nations International Day of Light observed annually on 16 May, the anniversary of the first observation of laser oscillation in 1960.  If you want to see how the International Day of Light has been a great success since its inauguration in 2018, follow this News Link here.  You can also download the latesr International Day of Light 2020 Reporthere.