Seminar : March 10th

New dimensions of spectroscopy; no fear of wild molecules

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

Jennifer P. Ogilvie 

Physics Department at the University of Michigan, Ann Arbor, Michigan, United States

Multispectral and Spatially-resolved Multidimensional Spectroscopy

Abstract: There is currently a revolution in optical spectroscopies to develop multidimensional approaches that provide sensitive probes of structure and dynamics in condensed-phase systems spanning decades in space and time. I will discuss our development of a multispectral multidimensional spectrometer enabling measurements from the ultraviolet, visible and mid-infrared as well as combination spectroscopies. I will illustrate some of the capabilities of the instrument through our efforts to probe the electronic structure and charge separation mechanisms in natural and artificial light-harvesting systems. I will also discuss our development of phase-modulation-based spatially-resolved multidimensional spectroscopy, enabling in vivomeasurements on biological systems and will discuss the promise of this new approach for imaging of biological and material systems. 

Bio: Jennifer P. Ogilvie is a Professor in the Physics Department at the University of Michigan, Ann Arbor. She received her B.Sc. from the University of Waterloo, her M.Sc. degree from Simon Fraser University, Canada, and her Ph.D. in Physics from the University of Toronto, Canada. She was a Postdoctoral Fellow in the Laboratory for Optics and Biosciences at the Ecole Polytechnique. Ogilvie’s group develops multidimensional spectroscopy and imaging methods and applies them to studies of ultrafast energy transfer and charge separation in natural and artificial photosynthetic systems.  She is a Sloan Fellow and a Fellow of the Optical Society of America.

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Invited

Vincent Wanie

Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany

Few-optical-cycle UV pulse generation and applications in molecular science

Abstract: Ultraviolet (UV)radiation being an essential element in a wide range of scientific areas, advances of UV light sources promise to have an impact not only for engineering new technologies but also for fundamental research. 

In molecular science, well-established spectroscopic methods have allowed to study in real-time the evolution of photo-induced chemical reactions with few-femtosecond (fs) and even sub-fs time resolution [1]. However, the investigation of UV-induced phenomena at such timescales is still in its infancy due to the technological challenges for the production and manipulation of ultrabroadband, few-fs UV pulses [2]. 

In this presentation, thecurrently available state-of-the-art technologies delivering few-fs UV pulses will first be discussed, together with their advantages and limitations.I will notably present the recent developments following our generation of sub-2-fs, 150 nJ UV pulses [3],obtained by third-harmonic generationof 800 nm, 5-fs pulses in argon gas.The light source is embedded into an all-vacuum beamline for dispersion-free spectroscopic applications, where UV pulses can be synchronized to either few-cyclenear-infrared or attosecond XUV (15-50 eV) pulses for time-resolved measurements.

Finally, the investigation of UV-induced dynamics in a few molecular targets will be presented, using the UV-pump/near-infrared-probe scheme. The results show that the unprecedented temporal resolution provided by our experimental setup allows us to resolve ultrafast phenomena within few tens of fs such as chiroptical switching effects in chiral molecules and non-adiabatic dynamics in halogenated hydrocarbons.Our work marks an important step forward in the field of molecular UV spectroscopy, while the application of our compact UV light source can be further extended to the study of a number of materials for photonic applications.

  1. F.Calegari et al., “Advances in attosecond science,” J. Phys. B: At. Mol. Opt. Phys 49, 062001 (2016).

2. V. Wanie et al., “Advances of ultraviolet light sources: towards femtosecond pulses in the few-cycle regime,” in Emerging Laser Technologies for High-Power and Ultrafast Science(IOP Publishing, 2021). 

3. M.Galli, V. Wanie et al., “Generation of deep ultraviolet sub-2-fs pulses,” Optics Letters 44, 1308-1311 (2019).

Bio: 

Since 07/2021: Senior Scientist (tenured) in the Attosecond Science group of the DESY Photon Science Division, Hamburg, Germany.

01/2021 – 06/2021: Postdoctoral researcher in the Attosecond Science group of the DESY Photon Science Division, Hamburg, Germany.

2015 – 2020: PhD in Energy and Materials Sciences, INRS-ÉMT, Canada

  • Funded by the Vanier Canada Graduate Scholarship.
  • Thesis title: Probing and controlling few-femtosecond dynamics with ultrashort laser pulses: from gases to solids.

2014 – 2015: Master Degree in Energy and Materials Sciences – Fast-track to PhD, INRS-ÉMT, Canada.

2010 – 2013: B. Sc.in Chemistry, Université de Sherbrooke, Canada.

Seminar : December 2nd

Winter special: Of Penguins, Ice and Frost

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

Anne Marie Kietzig

McGill University, Québec, Canada

About Penguin feathers, ice, metal and ultrafast pulses

Abstract: The body feather of the perpetually ice-free South American penguin is an excellent natural example of an anti-icing surface. The feather’s ice-shedding property is attributed to a flexible wire-like microstructure formed by so-called barbs and barbules, which are covered by nanogrooves. We have taken a bio-inspired approach in fabricating an engineering ice shedding surface by femtosecond laser micromachining fine woven metallic wire cloths to decorate the latter with characteristic laser-induced periodic surface structures (LIPSS). The mesh-like microstructure of the wire cloth provides a multitude of stress concentration and thus crack initiation sites, which together with the directionality and pattern repeat exhibited by the mesh structure, results in extremely small forces necessary to remove accreted ice. By appropriately choosing laser machining settings as well as the post processing environment, we have fabricated both hydrophilic and hydrophilic versions of the engineered anti-icing surface, which further enabled us to identify the role of surface chemistry in ice adhesion. In conclusion we present a bioinspired surface with both ice-shedding and water-shedding functionality

Bio: Anne-Marie Kietzig is an Associate Professor and Gerlad Hatch Fellow at the Department of Chemical Engineering at McGill University, Canada. She started her undergraduate education of Chemical Engineering and Economy Studies at the Technical University of Berlin, Germany, and continued her doctoral studies at the Department of Biological and Chemical Engineering at the University of British Columbia in Vancouver, Canada. Today she leads a research program in Biomimetic Surface Engineering, which combines laser micromachining for the generation of surface functionality with surface performance evaluations in contact with liquids. The fields of application are manifold and target tailoring optical properties, adhesion, drag, and friction.

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Invited

Philippe Lassonde

Institut National de la Recherche Scientifique – Énergie Matériaux Télécommunications, Québec, Canada

Temporal characterization of ultrashort laser pulses with Frequency-resolved optical switching (FROSt)

Abstract: We have developed an ultrashort laser pulse characterization technique called Frequency-Resolved Optical Switching (FROSt) based on the generation of free carriers in semi-conductors or low band-gap dielectric materials [1-4]. We have demonstrated the capacity to measure ultrashort pulses independently of their central wavelength, spectral bandwidth and polarization states. This method has interesting features as it works with common materials such as silicon, germanium or zinc selenide and as the signal is linear with the pulse to be characterized, providing augmented sensitivity for detection.  FROSt operates in a pump-probe scheme where the pump requires sufficient intensity to promote free carriers in the conduction band of the material resulting in an ultrafast drop of its transmissivity on the timescale of the pump duration. This  transmissivity switch is probed by the pulse to be measured. This mechanism enables to characterize ultrashort laser pulses without the phase-matching constraints observed with conventional techniques based on nonlinear processes in crystals. We have demonstrated FROSt to characterize (i) few-cycle pulses centered at wavelength from 0.8 to 14µm, (ii) ultra-broadband pulses of 2.25 octave in the near-infrared, (iii) low-energy pulses spread temporally to very long durations (i.e. 150nJ/40ps pulses), and  (iv) simultaneously two pulses with orthogonal polarization directions. In a nutshell, the FROSt technique provides a versatile and powerful tool for ultrashort laser pulse measurement.

1.            A. Leblanc, P. Lassonde, S. Petit, J. C. Delagnes, E. Haddad, G. Ernotte, M. R. Bionta, V. Gruson, B. E. Schmidt, H. Ibrahim, E. Cormier, and F. Légaré, “Phase-matching-free pulse retrieval based on transient absorption in solids,” Opt. Express 27, 28998-29015 (2019).

2.            B. Brizard, A. Leblanc, S. Petit, J.-C. Delagnes, É. Cormier, H. Ibrahim, F. Légaré, and P. Lassonde, “Single-shot phase-matching free ultrashort pulse characterization based on transient absorption in solids,” Opt. Express 28, 35807-35815 (2020).

3.            P. Lassonde, A. Laramée, H. Ibrahim, É. Cormier, F. Légaré, and A. Leblanc, “Polarization-independent pulse retrieval based on frequency resolved optical switching,” Opt. Express 29, 23225-23233 (2021).

4.            A. Leblanc, A. Longa, M. Kumar, A. Laramée, C. Dansereau, H. Ibrahim, P. Lassonde, and F. Légaré, “Temporal characterization of two-octave infrared pulses by frequency resolved optical switching,” Journal of Physics: Photonics 3, 045002 (2021).

Bio: Philippe Lassonde received his B.Eng. degree in engineering physics from the University Laval, Quebec city, in 2006, and the MSc. degree in physics from the Institut National de la Recherche Scientifique (INRS), Varennes, in 2009. Since 2009, he is employed at the ALLS facility as a research agent and he has been steadily involved in research activities in the field of ultrafast laser development and applications. He is author and coauthor of more than 100 papers published in international scientific journals and conference proceedings. His research interests include laser ablation of materials, ultrafast mid-infrared source development, secondary sources derived from high intensity laser-matter interactions and pulse compression/metrology.

Seminar : November 4th

Halloween special: spooky action – dead and alive

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

Benjamin Brecht

Paderborn University, Integrated Quantum Optics, Institute for Photonic Quantum Systems (PhoQS), Warburger Straße 100, 33098 Paderborn, Germany

Integrated quantum optics with pulsed light

Abstract: The notion of coherence is central to quantum optics. Quantum interference is verified with second-order coherence measurement, coherence times of pulsed quantum light are intimately linked to the purity of the underlying quantum states, and interferometric schemes can harness quantum resources to reach improved performances.

In our group, we study the coherence properties of pulsed quantum light and quantum processes both to understand them fundamentally and to harness them for photonic quantum technologies. To this end, we have built an extensive theoretical framework that allows us to treat spectrally broadband quantum processes. Key to this framework is the concept of pulsed temporal modes, which are the natural eigenbasis for describing pulsed quantum light. Based on this, we have developed several tailored quantum devices such as single- and few-mode photon-pair sources, or the quantum pulse gate – a dispersion-engineered frequency conversion process.

During the presentation, I will introduce the concept of temporal modes, give an overview over the capabilities of our group from technology to quantum applications and will conclude with discussing the coherence properties of nonlinear interferometry, which become particularly interesting when considering the interplay of coherences and quantum light.

Bio: Benjamin Brecht is the leader of the Quantum Networks part of the Integrated Quantum Optics group, led by Christine Silberhorn. Further, he is the manager of the interdisciplinary Institute for Photonic Quantum Systems (PhoQS) at Paderborn University, which aims to develop photonic quantum technologies in a full-stack approach. He received his PhD degree in 2014 for his work on engineered ultrafast quantum frequency conversion, during which he developed and demonstrated the quantum pulse gate. In 2015, he joined the Ultrafast Quantum Optics group of Ian A. Walmsley at the University of Oxford, to work on broadband atomic quantum memories. He was co-inventor of the ORCA quantum memory, which is now being commercialised as a tool for quantum technologies. He moved back to Paderborn in 2018 to take over the lead of the Quantum Networks part of the Silberhorn group. His research interests are centred around ultrafast quantum optics and the generation, manipulation, and application of pulsed quantum light in large photonic systems. Within PhoQS, he is focussing on building a photonic quantum computer, again based on pulsed quantum light

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Invited

Roberto Morandotti

Institut National de la Recherche Scientifique – Énergie Matériaux Télécommunications, Québec, Canada

Quantum Micro frequency combs

Abstract: The development of accessible next-generation technologies for quantum information science necessitates the realization and precise manipulation of complex entangled photon states on practical and scalable platforms. Furthermore, adapting these quantum photonic platforms to off-the-shelf optical telecommunications represents an important, yet challenging, milestone. Quantum frequency combs (QFCs) are a powerful tool towards this goal, since they enable the generation of complex photon states in just a single spatial mode as well as their control through the use of readily available fiber-based telecom components. Here, we make use of integrated QFCs (namely, micro frequency combs) for the first on-chip realization of complex entangled photon states in both the time and frequency domains. Furthermore, by using optical components that are compatible with telecom infrastructures, we are able to coherently control and process the generated photon states. Our results can pave the way towards the advancement of quantum technologies such as quantum communications for out-of-the-lab applications, as well as towards their compatibility with current optical telecommunication networks.

Bio: Roberto Morandotti received his M. Sc. degree in physics from the University of Genova, Genova, Italy, in 1993, and the Ph.D. degree from the University of Glasgow, Glasgow, U.K., in 1999. Since 2003, he joined the INRS-EMT, Varennes, Canada. He is author and coauthor of more than 1,000 papers published in international scientific journals and conference proceedings. His current research interests include integrated and quantum optics, photonics machine learning as well as Terahertz science and applications. He is a Fellow of the Royal Society of Canada, of the AAAS, of the IEEE, of theAPS, of the OSA, of the SPIE, and an E.W.R Steacie Memorial Fellow, as well as a recipient of the NSERC Synergy and Brockhouse Awards. He has served as a Chair and Technical Committee Member for several OSA, IEEE, and SPIE sponsored meetings

Seminar : October 7th

THz Photonics and applications

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

Jean-Michel Ménard

Department of Physics, University of Ottawa Center for Quantum 2D Materials NRC–uOttawa Joint Centre for Extreme Photonics Max Planck – uOttawa Centre for Extreme and Quantum Photonics http://menard.physics.uottawa.ca

THz photonics: technology for discovery

Abstract: New scientific instruments are often designed with the purpose to confirm hypotheses or theories. Some other times, they are “solutions seeking for a problem” to quote Maiman, the inventor of the first working laser. In either case, technological advances clearly drive scientific progress and lead to scientific breakthroughs. Especially, new and improved photonics instruments have been the catalysts behind many important discoveries, and not only in the field of optics, but also in biology, astronomy, and condensed matter physics. This has been a constant motivation for my research group to think about original optical configurations and components. More specifically, we are interested in the design and demonstration of new terahertz (THz) photonics devices. THz is a very active field of research and development focusing on optical technology operating around 1 THz (or 300 µm in wavelength). This radiation, located between the near-infrared and microwave regions, is generated and detected with relatively complex schemes, but it also has unique properties enabling many applications. For example, it can be used to image through seemingly opaque materials, identify molecular compounds from their low-energy spectrum, and monitor quasi-particles dynamics in condensed matter systems. However, many of these applications are still limited by a lack of efficient and affordable THz systems. In this presentation, I will show our recent progress on experimentally improving THz time-domain spectroscopy (THz-TDS) systems, notably by relying on ideas borrowed from the field of nonlinear optical propagation in optical fibers and periodically patterned semiconductor crystals.

[1]   W. Cui et al. Broadband and tunable time-resolved THz system using argon-filled hollow-core photonic crystal fiber. APL Photonics 3, 111301 (2018)

[2]   A. Halpin, N. Couture and J.-M. Ménard. Optical pulse structuring in gas-filled hollow-core kagomé PCF for generation and detection of phase-locked multi-THz pulse. Optical Materials Express 9, 3115 (2019)

[3]   A. Halpin, W. Cui, A. W. Schiff-Kearn, K. M. Awan, K. Dolgaleva, J.-M. Ménard. Enhanced terahertz detection efficiency via grating-assisted noncollinear electro-optic sampling. Physical Review Applied 12, 031003 (2019)

Bio: Jean-Michel Ménard is Associate Professor and principal investigator of the Ultrafast Terahertz Spectroscopy Lab at the University of Ottawa. He completed his PhD in 2010 under the guidance of Henry van Driel at the University of Toronto. He was then awarded a Humboldt Fellowship to investigate ultrafast dynamics with terahertz spectroscopy in the lab of Rupert Huber at the University of Regensburg. In 2014, he joined the Russell Division at the Max Planck Institute for the Science of light in Erlangen as a postdoctoral researcher and finally moved back to Canada in 2016 to start a new research program combining photonics and condensed matter physics. He is a fellow of the Max Planck-uOttawa Centre for extreme and quantum photonics and the NRC-uOttawa Joint Centre for Extreme Photonics (JCEP). His research interests focus on time-resolved terahertz spectroscopy of quantum materials and the development of new THz systems relying on photonic crystal fibers and metasurfaces.

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Invited

David Purschke

University of Alberta, Edmonton, Alberta, Canadá.

Time-resolved Terahertz Spectroscopy of double-helix SnIP nanowires  

Abstract: Time-resolved THz spectroscopy (TRTS) is a powerful ultrafast pump-probe technique that enables measurement of the complex photoconductivity spectrum in materials with sub-picosecond temporal resolution. In our group, TRTS has been applied extensively to study semiconductors and nanomaterials, allowing us to extract parameters such as carrier mobility, and leading to new insight into the nature of carrier transport in nanostructured materials. In this talk, I give a brief introduction to the TRTS technique focusing on our recent work studying tin iodide phosphide (SnIP), a quasi-1D van der Waals semiconductor with an inorganic double-helix structure. SnIP, first reported in 2016, is an exciting new material with remarkable mechanical properties (flexibility and softness) that has shown promise in photocatalytic water splitting. To date, however, very little is known about it’s optical and electronic properties. Using TRTS, we make the first measurement of the carrier mobility in SnIP, which is found to be as high as 280 cm2V-1s-1, suggesting it could be an excellent new material for flexible electronics applications. Additionally, studying the density-dependent photoconductivity suggests that carrier localization due to nanogranular structure dominates the dispersion of the spectra, which is consistent with our studies of the recombination dynamics that indicate a large trap density. This suggests that a significant enhancement of the carrier mobility and lifetime could be achieved with improved synthesis or processing, which would greatly improve the application potential for SnIP. Finally, I summarize our ab-initio studies of the electronic structure of SnIP, which, surprisingly, shows signatures of a 2D-like behavior in the conduction bands. The potential of alternative ultrafast techniques to probe this unique structure is discussed.

Bio: David Purschke received his MSc in physics from the University of Alberta followed by a joint doctoral degree between the University of Alberta and Technical University of Munich as part of the ATUMS Graduate School for Hybrid Functional Materials. He is currently a National Research Council Postdoctoral Fellow with the Joint Attosecond Lab in Ottawa.

Seminar : September 2nd

Laser applications – from plants to the cosmos.

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

Byung-Kook (Brian) Ham

Global Institute for Food Security, Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada

Plant vascular system acts as information superhighway in plants; What is the role of plant vascular system in plant development, physiology and agriculture?

Abstract: Application of nutrient fertilizers enables achievement of increased agricultural crop productivity. It has been important research programs to enhance nutrient use efficiency in crop species for permitting sustainable crop yield and, thereby ensure global food security under limited nutrient fertilizer input. During reduced mineral nutrient availability, plant roots are the first organs to recognize these stress conditions through root-localized mechanisms. These stresses can be converted into root-derived signals that are transported via the xylem for communicating these challenging conditions to the shoot. The root-derived signals, delivered into vegetative tissues, elicits generation of specific output signals that enter the phloem to transfer commands from the shoot to the root for integrating the demands for various developmental and physiological processes. Therefore, it has been proposed that the plant vascular system functions as an effective shoot-root communication route in mineral nutrient homeostasis. Recent studies have been discussed in the content of information macromolecules, including proteins and various forms of RNAs, in phloem, which function as mediators to integrate sophisticated regulatory networks between shoots and roots. It raised the question as to whether the phloem has evolved the delivery capacity of specific stress-signaling molecules for regulation of adaptive developmental responses when plants face mineral nutrient limitation. We will discuss the function of the phloem as an integrator to operate long-distance gene regulation for optimizing plant developmental and physiological processes under mineral nutrient-stress conditions, by delivering a cascade of signaling agents to various developing sink tissues.

Bio: Byung-Kook (Brian) is currently an Assistant Professor in the Department of Biology at University of Saskatchewan and also affiliated with the Global Institute for Food Security (GIFS) as a research chair.

Brian received his BSc, MSc and PhD degrees in Molecular Biology from Korea University, South Korea. He joined in the Department of Plant Biology as University of California-Davis as a postdoctoral fellow, Assistant and Associate Project Scientist. His research has been focused on profiling signaling components in the plant vascular tissues and characterizing their functions within plants. He was recently awarded an New Fronter Research Fund – Exploration for synchrotron-based plant imaging to analyze distribution of mineral elements under nutrient-starvation stress conditions.

Invited

Brant Billinghurst

Senior Scientist, Beamline Responsible, Far-Infrared, Canadian Light Source. Inc., University of Saskatchewan, Canada

THz Spectroscopy at the CLS: From Quantum to the Cosmos  

Abstract: The Far-Infrared beamline at the Canadian Light Source provides access to a number of techniques that leverage the high brightness of the Synchrotron in the Far-Infrared and Terahertz, to provide high quality spectral information for a number of different applications.

This presentation will summarize the techniques available on the Far-Infrared beamline, including High-resolution Gas Phase Spectroscopy, Terahertz Microscopy and Attenuated Total Reflectance. It will also provide examples of the applications of Terahertz spectroscopy. Terahertz spectroscopy has vast applications, in fields far ranging across agriculture, life sciences, materials, and more. This talk will focus on a small number of fields that are being actively studied on the beamline. A simple example will show that, although many materials do not have strong absorptions, this can be used to benefit analytical analysis. Also shown will be the use of Terahertz spectroscopy to monitor reactions under extreme conditions, in this case the formation of HgF4 at pressures of 30 GPa.  Furthermore, Terahertz spectroscopy can be used to probe interesting phenomena like Quantum Monodromy and Quantum Tunnelling.  The importance of Terahertz spectroscopy to Astrochemistry will also be discussed. Terahertz spectroscopy is essential to understand the data provided by telescope and satellite based spectrometers, as well as being used to better understand the environment on other astronomical bodies, specifically the atmosphere of Titan, and to evaluate the possibility that liquid water could have been present on ancient Mars.

Bio: Brant Billinghurst received a Ph.D. in Chemistry from the University of Manitoba in 2004. Upon completion of his degree he held a Postdoctoral position at the University of Alberta, working with Resonance Raman Spectroscopy. Remaining in Alberta Dr. Billinghurst accepted a position as a Canadian Government Laboratories Visiting Fellow at Natural Resources Canada – CANMET Energy Technologies Centre, where his research focused on using Vibrational Spectroscopy to study materials of interest to the energy industry. In 2008 Dr. Billinghurst made the move to his current position as Senior Scientist responsible for operation of the Far-Infrared Beamline at the Canadian Light Source, and has been highly active in research involving Coherent Synchrotron Radiation. Dr. Billinghurst has also held the position of adjunct assistant professor at the University of Lethbridge since 2009.

Seminar : July 8th

High power lasers

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

Félicie Albert

Lawrence Livermore National Laboratory, CA, USA

Laser plasma accelerators: next generation x-ray light sources

Abstract: Bright sources of x-rays, such as synchrotrons and x-ray free electron lasers (XFEL) are transformational tools for many fields of science. They are used for biology, material science, medicine, or industry. Such sources rely on conventional particle accelerators, where electrons are accelerated to gigaelectronvolts (GeV) energies. The accelerating particles are also wiggled in magnetic structures to emit x-ray radiation that is commonly used for molecular crystallography, fluorescence studies, chemical analysis, medical imaging, and many other applications.  One of the drawbacks of synchrotrons and XFELs is their size and cost, because electric field gradients are limited to about a few 10s of MeV/M in conventional accelerators.

This seminar will review particle acceleration in laser-driven plasmas as an alternative to generate x-rays. A plasma is an ionized medium that can sustain electrical fields many orders of magnitude higher than that in conventional radiofrequency accelerator structures. When short, intense laser pulses are focused into a gas, it produces electron plasma waves in which electrons can be trapped and accelerated to GeV energies. This process, laser-wakefield acceleration (LWFA), is analogous to a surfer being propelled by an ocean wave. Betatron x-ray radiation, driven by electrons from laser-wakefield acceleration, has unique properties that are analogous to synchrotron radiation, with a 1000-fold shorter pulse. This source is produced when relativistic electrons oscillate during the LWFA process.

An important use of x-rays from laser plasma accelerators we will discuss is in High Energy Density (HED) science. This field uses large laser and x-ray free electron laser facilities to create in the laboratory extreme conditions of temperatures and pressures that are usually found in the interiors of stars and planets. To diagnose such extreme states of matter, the development of efficient, versatile and fast (sub-picosecond scale) x-ray probes has become essential. In these experiments, x-ray photons can pass through dense material, and absorption of the x-rays can be directly measured, via spectroscopy or imaging, to inform scientists about the temperature and density of the targets being studied.  

Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344, supported by the LLNL LDRD program under tracking code 13-LW-076, 16-ERD-024, 16-ERD-041, supported by the DOE Office of Fusion Energy Sciences under SCW 1476 and SCW 1569, and by the DOE Office of Science Early Career Research Program under SCW 1575.

Bio: Félicie Albert is a scientist at the Lawrence Livermore National Laboratory in the National Ignition Facility and Photon Science directorate, and the deputy director for LLNL’s center for High Energy Density Science.

Félicie earned her PhD in physics in 2007 from the Ecole Polytechnique in France, her MS in Optics from the University of Central Florida in 2004, and her BS in engineering from the Ecole Nationale Supérieure de Physique de Marseille, France, in 2003. Her areas of expertise include the generation and applications of novel sources of electrons, x-rays and gamma-rays through laser-plasma interaction, laser-wakefield acceleration, and Compton scattering. She has conducted many experiments using high-intensity lasers at various facilities around the world.

Félicie received the Presidential Early Career Award for Scientists and Engineers (PECASE) in 2019, was awarded a 2016 DOE Early Career Research Program Award. She is the recipient of the 2017 American Physical Society (APS) Katherine E. Weimer Award and of the 2017 Edouard Fabre. She was elected a senior member of the Optical Society (OSA) in 2019, a Fellow of the APS (Division of Plasma Physics) in 2019 and a National Academy of Sciences Kavli Fellow in 2020.

She has over 70 refereed publications and has given over 35 invited talks at international conferences. She is a member of the International Committee of Ultra Intense Lasers (ICUIL), of the APS-DPP executive committee, of the Assessment of High Energy Density (HED) Physics NAS committee, and the current Chair of LaserNetUS.

Candra

Invited

Chandra Breanne Curry

University of Alberta / SLAC

Shrinking particle accelerators with petawatt lasers: ion beams from relativistic laser-plasma interactions  

Abstract: High-intensity laser-plasma interactions have the potential to produce unprecedented acceleration gradients for the development of compact particle accelerators. Simulations have identified relativistically enhanced ion acceleration mechanisms with recently achievable peak laser intensities and sophisticated, near-critical density target designs. 

In this talk, I will first present the development of cryogenic liquid hydrogen and deuterium jets with tunable thickness down to less than 1 micron. These jets have been fielded in experiments to systematically investigate the complex interplay between target and laser conditions and the effect on ion emission. Small variations of the target density profile or laser pulse shape may favor one of many competing acceleration mechanisms or support co-existence. By irradiating planar jets with the Texas Petawatt laser (135 J, 135 fs, 1021 W/cm2), we have entered a regime where bright, high-energy proton and deuteron beams are produced. This work suggests that future applications of machine learning techniques and active laser–target–diagnostic feedback loops, enabled by the high-repetition rate compatibility of the cryogenic jet target, are a promising new path to fully optimize laser-driven ion beams for applications. 

Bio: Chandra Breanne Curry is currently a PhD Candidate in the Department of Electrical and Computer Engineering at the University of Alberta and is jointly affiliated with the High Energy Density Science Division at SLAC National Accelerator Laboratory. She was recently awarded an NSERC Postdoctoral Fellowship for pump-probe experiments on fusion-relevant materials at X-ray free electron laser facilities. Her research is performed primarily in the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS) and high-intensity laser facilities within the LaserNetUS consortium (https://www.lasernetus.org/). 

Seminar : June 3rd

THz Science

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Keynote

François Blanchard

Ecole de technologie Supérieure, Québec

Improving sensitivity in terahertz applications

Abstract: Terahertz time-domain systems require a certain technical expertise to achieve sufficiently sensitive performance for accurate measurements. In this presentation, we will review some basic elements of THz wave detection by electro-optical sampling (e.g., photodiodes and lock-in amplifier). Following this introduction, we will review the latest developments in the generation of intense THz waves allowing fast rate nonlinear spectroscopy measurements. Finally, we will discuss a promising approach on the use of metasurfaces and active MEMS structures to improve the performance of THz systems and reveal information with subwavelength accuracy. 

Bio: François BLANCHARD, professor in the Department of Electrical Engineering at the École de Technologie Supérieure (ÉTS) since 2015 has obtained the ÉTS Chair in Terahertz (THz) Optoelectronics (2016-18) and has recently obtained a Canada Research Chair in THz Wave Encryption (2021-26). Over the past thirteen years, he has accumulated over 2400 citations with more than 50 scientific papers, 5 patents, one book chapter and three major journal articles in the field of THz waves. He has contributed significantly to the establishment of a world reference in high field THz pulse generation using nonlinear crystals, as well as the development, in collaboration with Olympus Corp. of the first video rate THz microscope. In addition, he has extensive expertise in the field of non-destructive testing of materials with a decade of industrial experience. His recent contributions include a project on non-contact characterization of THz wave printable electronics devices. This project led his first PhD student (Ms. Zhuldybina) to start her company (TraQc) in THz inspection as part of the Centech Acceleration program.   https://www.etsmtl.ca/en/research/professors/fblanchard/#Publications

Invited

Shawn Sederberg

University of Ottawa

Transferring light structure to current structure for THz magnetic impulses  

Abstract: The fundamental link between currents and magnetic fields is central to the theory of electromagnetism and to magnetic field sources. Our ability to structure magnetic fields in space and time is limited by the electrical conductors and superconductors used to carry currents in electromagnets. Adding high-bandwidth temporal structure to magnetic fields would enable exploration of ultrafast magnetic-field-induced dynamics in nature and the ultimate speed limits of magnetic-field technology. Precise control over their spatial structure would facilitate manipulation and optimization of magnetic fields for finer control of free-electron lasers, electron microscopes, spintronic devices, and magnetic skyrmions.   In this work, we explore the possibility to transfer spatial and temporal structure from femtosecond laser pulses to currents in solids and gases via the interference of quantum pathways, or coherent control. In the first half of this seminar, I will demonstrate how structured light can be used to sculpt and reconfigure complex current arrangements including ring currents in semiconductors via coherent control. These currents can be used to control THz-bandwidth magnetic fields, or to serve as active metasurfaces for THz radiation. Subsequently, I will present our efforts towards generating structured THz pulses radiated from an air plasma channel excited by two-colour laser fields. By in-situ monitoring of currents within the plasma channel, we actively stabilize the THz waveforms to fluctuations in both the two-colour interferometer and the plasma channel. Finally, I will discuss our ongoing efforts to generate and measure Tesla-scale magnetic fields with femtosecond rise-times. 

Bio: Shawn completed his Ph. D. in Engineering Physics at the University of Alberta and was awarded the Governor General’s Gold Medal. Subsequently, he held a Banting Postdoctoral Fellowship while working at the Max Planck Institute for Quantum Optics in Garching, Germany. He is currently a Research Associate and Project Leader at the Joint Attosecond Science Laboratory at the University of Ottawa and National Research Council Canada.

Seminar : May 6th

10:30 Vancouver – 11:30 Edmonton – 12:30 Winnipeg – 13:30 Montreal – 14:30 Halifax

Olga Smirnova

Max Born Institute, Berlin

Ultrafast chirality: twisting light to twist electrons

Abstract: I will describe several new, extremely efficient approaches to chiral discrimination and enantio-sensitive molecular manipulation, which take advantage of ultrafast electronic response [1,2]. One of them is based on the new concept of synthetic chiral light [3], which can be used to trigger bright nonlinear optical response in the molecule of a desired handedness while keeping its mirror twin dark in the same frequency range. The other is based on the new concept of geometric magnetism in photoionization of chiral molecules and leads to a new class of enantiosensitive observables in photoionization [4]. Crucially, the emergence of these new observables is associated with ultrafast excitation of chiral electronic or vibronic currents prior to ionization and can be viewed as their unique signature.

[1] S Beaulieu et al, Photoexcitation circular dichroism in chiral molecules, Nature Physics 14 (5), 484,2018

[2] AF Ordonez, O Smirnova, Generalized perspective on chiral measurements without magnetic interactions, Physical Review A 98 (6), 063428, 2018

[3] D Ayuso et al, Synthetic chiral light for efficient control of chiral light–matter interaction, Nature Photonics, 2019, doi: 10.1038/s41566-019-0531-2

[4] AF Ordonez, D Ayuso, P. Decleva, O Smirnova “Geometric magnetism and new enantio-sensitive observables in photoionization of chiral molecules” (in preparation)

Bio: Olga Smirnova graduated from the Physics Department of the Moscow State University in 1996 and received her PhD there in 2000, continuing as assistant professor. In 2003 she received the Lise-Meitner Fellowship of Austrian Science Foundation (FWF) and joined the Vienna University of Technology as a postdoctoral fellow. In 2005 she moved to the National Research Council (NRC) in Ottawa, Canada, where she became a permanent staff scientist in 2006.  In 2009 she received the SAW award of the Leibniz society and moved to the Max Born Institute to establish her own Strong Field Theory research group, which she continues to lead. Since 2016 she also holds full professorship at the Technical University Berlin. In 2010 Olga has received the Karl-Scheel-Preis of Physikalischen Gesellschaft zu Berlin and in 2020 she has received the Ahmed Zewail Award in Ultrafast Science & Technology of the American Chemical Society in 2020. Olga’s current research focuses on imaging and control of ultrafast electron dynamics in atoms, solid state materials, and molecules, especially chiral molecules.

Arthur K Mills

University of British Columbia

Ultrafast Nonlinear Optics in Femtosecond Enhancement Cavities: High Harmonics and Beyond

Abstract: In this talk I will present our work on femtosecond enhancement cavity (fsEC) XUV sources and their application to time- and angle-resolved photoemission spectroscopy (TR-ARPES). We use nonlinear Yb-doped fiber amplifiers to produce pulses of tunable duration (i.e. 80-300 fs), which are further enhanced in the fsEC and used for intra-cavity HHG. This allows us to emphasize higher time resolution or higher energy resolution depending on the particular ARPES application. I will also discuss new modes of nonlinear pulse propagation in the fsEC that produce pulse durations below 30 fs, and may provide new opportunities for nonlinear optics in fsECs.

Bio: Art Mills has a background in stable laser development, and develops advanced source technologies for application of high repetition rate ultrafast sources in condensed matter spectroscopy such as time- and angle-resolved photoemission spectroscopy.