SQUARE Brussels Meeting Centre
Brussels, Belgium
3 - 7 April 2016
Plenary Events
Hot Topics I
Date: Monday 4 April 2016
Time: 8:45 AM - 11:00 AM
8:45 to 8:55
Welcome and Introduction
Robert A. Lieberman,
Lumoptix LLC, United States
SPIE President

Joseph W. Goodman Book Writing Award Presentation
Recipient: Valery V. Tuchin, Saratov State University, Russia

The Joseph W. Goodman Book Writing Award recognizes a recent and outstanding book in the field of optics and photonics that has contributed significantly to research, teaching and/or the optics and photonics industry. The award is presented to Valery V. Tuchin for his book, Tissue Optics: Light Scattering Methods and Instruments for Medical Diagnosis, 3rd ed., (SPIE Press, 2015).

Welcome Address
Francis Berghmans, Vrije Univ. Brussel, Belgium
Symposium Chair

Introduction to Hot Topics

Hugo Thienpont, Vrije Univ. Brussel, Belgium
Honorary Chair

9.05 to 9.30
Lighting the Future of Photonics: the Legacy of the International Year of Light
John Dudley, Université Franche-Comte, France

The International Year of Light and Light-based Technologies 2015 (IYL2015) has been a tremendously successful global initiative with thousands of events reaching millions of people in over a hundred countries. United by the interdisciplinary theme of light, IYL2015 counts amongst the most successful and visible of any of UNESCO’s international observances, bringing together an unprecedentedly diverse range of participants committed to raising awareness of the myriad ways that light touches us all. The variety of events that has taken place worldwide is truly astonishing, ranging from small school events in developing countries, to large scale public outreach, to high level meetings between world political leaders and Nobel laureate scientists. This presentation will review the achievements of the year, present some selected highlights, and discuss ongoing initiatives that will leave an enduring legacy.

Biography: President of the Steering Committee of the International Year of Light 2015, John Dudley has more than two decades experience in science research, teaching, administration, and public outreach. His research is in various areas of ultrafast and nonlinear optics, and he is currently funded by the ERC to study extreme events in nature. He has received numerous distinctions including the 2014 SPIE President’s Award, the OSA Hopkins Award, the CNRS Silver Medal and Fellowships of the OSA and IEEE. In addition to his efforts steering the International Year of Light he also served as European Physical Society President (EPS) from 2013-2015. Born in New Zealand, he also holds citizenship of Ireland and France.

9:30 to 10:15
Current Challenges and Perspectives in High Power Fiber Lasers
Cesar Jauregui Misas, Friedrich Schiller-Univ. Jena, Germany

As the output power of the first lasers started to grow, it became evident that they were severely limited by thermal effects. In particular, the heat load generated during the laser process led to the generation of a thermal lens that resulted in strong distortions of the output beam. As a consequence the original thick-rod geometry of the first active media was mostly abandoned in favour of advanced geometries such as the thin-disk, the slab or the fiber. These geometries offer a significantly increased surface to active volume ratio which favours the efficient dissipation of the heat generated during laser operation. The fiber geometry, in particular, has proven to be particularly robust against thermal problems leading to an impressive development of the performance of fiber lasers over the last 20 years, which has earned optical fibers a solid reputation as a highly power scalable laser concept. As a statement of the outstanding thermal properties of optical fibers serves the fact that these systems are able to deliver the highest average powers with diffraction limited beam quality in spite of the material most fibers are made of (silica glass) having a thermal conductivity around one order of magnitude lower than that of the crystals used in thin disk and slab lasers and amplifiers. However, even fibers are not completely immune against thermal effects and, due to the extremely high output average powers reached in the past years, a further scaling of the output power is currently hampered by thermal issues.

The most severe manifestations of thermal effects in active optical fibers are the so-called mode instabilities. This phenomenon results in the sudden degradation of the beam quality emitted by a high-power fiber laser system once that a certain average power threshold is reached. This beam quality degradation is accompanied by temporal fluctuations of the beam profile. Mode instabilities have been the focus of intense research recently since they currently limit the further development of fiber lasers systems in terms of average power and undermine one of the fundamental pillars upon which the reputation of fiber lasers systems has been built: their ability to emit nearly diffraction limited beams at very high average powers.

In this talk the evolution of high-power laser systems (and in particular pulsed systems) over the past years will be reviewed paying special attention to the different limitations found on the way and the solutions provided to them. Then current limitations, especially mode instabilities, will be described and different mitigation techniques will be presented. Finally, the development strategies of a new generation of high-power high-energy fiber laser systems will be discussed.

Biography: Dr. César Jauregui Misas was born in Santander, Spain, in 1975. He received both his Telecommunication Technical Engineering degree and his Telecommunication Engineering degree at the University of Cantabria. In 2003, he got his Ph.D. degree at that same University. In 2005 he began a two-year post-doc stay at the Optoelectronics Research centre, where he investigated the phenomenon of slow-light in optical fibers. Since 2007 he is working at the Institute of Applied Physics in Jena. His primary research concerns are high-power fiber lasers, non-linear effects and mode instabilities in optical fibers and. César Jauregui has co-authored around 250 papers presented in conferences and scientific journals.

10:15 to 11:00
Attosecond Band-Gap Dynamics
Martin Schultze, Max-Planck-Institute for Quantum Optics and Ludwig Maximilians Univ., Germany

As one of the fascinating applications of femtosecond laser technology attosecond soft-X-ray pulses were first demonstrated 15 years ago. This talk will address how their meanwhile routine availability permits time resolved spectroscopy in a wide range of gas phase systems allowing to test standard assumptions of light-matter interaction with sub-attosecond resolution. More recently, attosecond solid state spectroscopy provides us with a time-domain understanding of electron dynamics also in solids. I will discuss experiments allowing the real time observation of the excitation of electrons across the band gap of semiconductors and dielectrics, the resulting band structure modifications and the nonlinear polarization response of dielectric materials. These studies shed light on the physical phenomena behind the interaction of ultrashort laser pulses with matter and particular interest is in the exploration of the dynamics of optical nonlinearities. In principle, such nonlinear phenomena allow to control solid state electronic properties with light wave frequencies and thus could serve as building block for ultrafast metrology and signal manipulation. Our recent findings indicate that few-cycle laser pulses with electric fields up to several Volts/Ångstrom can modify the electronic system of band-gap materials with sub-femtosecond response time followed by the instantaneous recovery after passage of the laser field. The quantitative determination of the amount of dissipation associated to each optical signal manipulation reveals the feasibility of dielectric optical switching at clock rates approaching optical frequencies.

Biography: Martin Schultze studied physics at the ETH Zurich and received his PhD at the LMU Munich, Germany for attosecond gas-phase experiments leading to the discovery of the unexpected delay in the photoelectric effect. In the groups of Ferenc Krausz at the Max Planck Institute of Quantum Optics and Steve Leone at the University of California, Berkeley he established attosecond spectroscopy as quantitative tool to time resolve solid-state electron dynamics that now allows to test the suitability of novel regimes of extreme light-matter interaction for ultrafast signal manipulation.

11:00 to 11:40 Coffee Break
Hot Topics II
Date: Tuesday 5 April 2016
Time: 4:30 PM - 6:00 PM
16.30 to 16.40: Welcome Address:
IN MEMORIAM: Wolfgang Sandner, ELI-DC director and laser scientist

Wolfgang Sandner, TU Berlin, Germany and ELI-DC International Association AISBL, The "Extreme Light Infrastructure" ELI, Belgium


16.40 to 17.20
Ultrahigh Resolution Models of the Human Brain: Computational and Neuroscientific Challenges
Katrin Amunts, Director, Institute of Neuroscience and Medicine in INM-1, Forschungszentrum Jülich and Cecile and Oskar Vogt Institute for Brain Research, Univ. of Düsseldorf (Germany)

The human brain is characterized by a multi level organization. Brain models at microscopical resolution provide the bridge between the cellular level of organization and that of cognitive systems. Data size and complexity of brain organization, however, make it challenging to create them. Cytoarchitectonic mapping strategies, as well as 3D-Polarized Light Imaging for analysing nerve fibre bundles and single axons will be discussed. Models of cellular and fiber architecture will be shown, including a new BigBrain data set, based on advanced ICT, thus opening new perspectives to decode the human brain.

Biography: Katrin Amunts did postdoctoral work in the C. & O. Vogt Institute for Brain Research at Duesseldorf University, Germany. In 1999, she moved to the Research Centre Juelich and set up a new research unit for Brain Mapping. In 2004, she became professor for Structural-Functional Brain Mapping at RWTH Aachen University, and in 2008 a full professor at the Department of Psychiatry, Psychotherapy and Psychosomatics at the RWTH Aachen University as well as director of the Institut of Neuroscience and Medicine (INM-1) at the Research Centre Juelich. In 2013, she became a full professor for Brain Research at the Heinrich-Heine University Duesseldorf, director of the C. and O. Vogt Institute for Brain Research, Heinrich-Heine University Duesseldorf and director of the Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich.
Since 2007 Katrin Amunts is a member of the editorial board of Brain Structure and Function. Since 2012 she is member of the German Ethics Council. She is the programme speaker for the programme “Decoding the Human Brain” of the Helmholtz Association, Germany. Since 2013 Katrin Amunts is leading the Subproject 2 “Strategic Human Brain Data” and a member of the Board of Directors of the European FET-Flagship “The Human Brain Project”.

17.20 to 18.00
Exciting and Detecting new Contrast in Biomedical Optics
Sarah Bohndiek, Univ. of Cambridge, VISION Lab. and Cancer Research UK Cambridge Institute (United Kingdom)

Oxidative stress and metabolic alterations derived from inflammation and tumor growth lead to hypoxia and angiogenesis in cancer and are associated with disease aggressiveness as well as the evolution of drug resistance. There are few validated, non-invasive, methods to detect the spatiotemporal distribution of these processes. To overcome this limitation and help to elucidate the role of oxygen in cancer, we aim to create and apply novel imaging methods to study oxygen delivery and utilization in preclinical models and in patients. In this talk, I will given an overview of how biomedical optics can aid this research effort and focus on two emerging approaches: optoacoustic and hyperspectral imaging, detailing both their technological development as well as giving examples of their biomedical application in living subjects.

Biography: Dr Sarah Bohndiek completed her PhD in Radiation Physics at University College London in 2008 and then worked in both the UK and the USA as a postdoctoral fellow in molecular imaging. Since 2013, she has led the VISION laboratory at the University of Cambridge, developing new techniques for spectral imaging of oxygen and oxidative stress in cancer. These techniques have been applied to study both disease development and the emergence of drug resistance and are now translating into the clinic. Sarah has published over 30 research articles on molecular imaging of cancer, which have received over 950 citations. She was awarded the Institute of Physics Paterson Medal, WISE Research Award and MSCA Prize in 2014 recognition of this work.
Hot Topics III
Date: Thursday 7 April 2016
Time: 8:45 AM - 10:20 AM
8.45 to 8.50:Introduction

8.50 to 9.35
Mesoscale Tissue Mechanics: the New Promise of Mechanical Contrast Probed with Optics
David D. Sampson, University of Western Australia

The mechanics of cells and tissues is important in a variety of ways that drives major topics of research in cell biology, biophysics and medicine. Arguably, research on the cellular and sub-cellular scale and, at the other extreme, on the whole organ scale of medical imaging, is being well served by existing imaging methods. The gap in the spatial resolution spectrum between these two extremes presents an opportunity to be filled by optics, in probing length scales from the few micrometers to perhaps 10-100 times that. Such scales are relevant to probing a cell and convey the potential to study cell mechanics in situ in real tissues. They also convey the potential to resolve heterogeneous tissue structures, such as cancer, which could aid in the more effective surgical removal of tumors. Mechanical properties are important to measure in their own right, but additionally they also represent an alternative form of contrast to that of optical properties, which provides new opportunity in imaging tissues. Probing mechanics with optics is not new, but various aspects have converged recently to make possible high-contrast, high-resolution imaging of tissue mechanics. This plenary will try to tease out this story, demonstrate progress, and highlight where the field might go in the future.

Biography: Professor David Sampson heads the Optical+Biomedical Engineering Laboratory and is Director of the Centre for Microscopy, Characterisation & Analysis at The University of Western Australia. He directs the Western Australian nodes of the Australian Microscopy & Microanalysis Research Facility and the National Imaging Facility (Australia). He is an SPIE Fellow, OSA Fellow, and a senior member of the Institute of Electrical & Electronics Engineers. Prof. Sampson’s research interests are in the science and applications of light in medicine and biology. His research is focused on the translation of microscopy techniques to imaging in the living body – medical microscopy. He was awarded the IEEE Photonics Society’s Distinguished Lecturer Award in 2013 for the Microscope-in-a-Needle, a deep tissue imaging platform. His other interests are in optical elastography, the microscale imaging of tissue stiffness, and parametric imaging of other tissue properties, such as optical attenuation, birefringence, and speckle dynamics to detect microvasculature, with a view to creating a suite of tools to comprehensively characterise the tissue microenvironment.

9:35 to 10:20
Single-Photon, Ghost Imaging with a Camera
Miles Padgett, University of Glasgow, United Kingdom

Conventional imaging systems use light that is scattered or transmitted by the object and subsequently imaged. Alternatively, Ghost Imaging systems use down-conversion sources that produce twin light beams within which the photons are position-correlated. One of these light beams then illuminates an object while the image information is recovered from the other beam that seemingly spookily has never interacted with the object!

Early demonstrations of ghost imaging used scanning detectors but our use of a camera increases the optical efficiency of detection in proport to the number of image pixels. In our latest work we are developing a camera-based ghost imaging system where the correlated photons have significantly different wavelengths. Infrared photons at 1550 nm illuminate the object and all those which are transmitted are detected by a single-pixel, single-photon avalanche diode. The image data are recorded from the coincidently detected, position-correlated, visible photons at 460 nm using an image-intensified, photon-counting camera. The efficient transfer of the image information from infrared illumination to visible detection wavelengths and the ability to count single-photons allows the acquisition of an image whilst illuminating the object with an extremely low optical flux. This wavelength-transforming ghost imaging technique has potential for the imaging of light-sensitive specimens or where covert operation is desired.

Biography: Miles Padgett holds the Kelvin Chair of Natural Philosophy at the University of Glasgow. He leads QuantIC, a quantum imaging centre and one of four Quantum Technology hubs in the UK. In 2001 he was elected a Fellow of the Royal Society of Edinburgh (RSE) and in 2014 a Fellow of the Royal Society, the UK's National Academy. In 2009, with Les Allen, he won the Institute of Physics Young Medal, in 2014 the RSE Kelvin Medal and in 2015 the Science of Light Prize from the European Physical Society.

10:20: Adjourn

10:20 to 10:50: Coffee Break
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