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The rapid advances in ultrafast laser technology have resulted in widespread availability of robust, practical laser sources for driving novel interaction physics inside of materials. As a result, useful applications for these sources have emerged in many different fields, from micromachining and THz imaging to nonlinear microscopy and semiconductor testing to laser surgery and communications. Now in its twenty-second year, this conference is the premier venue for discussing the development of new ultrafast laser sources, the manipulation and characterization of ultrashort pulses as well as their potential for opening new biomedical, scientific, and industrial applications. We anticipate a larger conference than ever that will bring together a multi-disciplinary group consisting of university researchers from diverse fields, as well as scientists and engineers from industry. A program that includes invited and tutorial presentations will provide the context for contributed talks and posters, and for stimulating discussions.

We encourage submission of papers on all aspects of ultrashort pulsed lasers and the novel ultrafast science that drives unique optical interactions for probing and processing all types of materials. In addition, all graduate and undergraduate students are encouraged to enter their submissions in the Student Competition for best presentation (see below).

General topics include, but are not limited to, the following areas:
Thanks to generous corporate sponsorship, we are happy to announce that a student competition will be held again this year. Due to the great success in previous years, the competition will be a general best student award, taking posters and talks into account. The winner will be announced and awarded a $1000 cash prize to the best student paper with the runner-up students receiving a cash prize as well.

To nominate yourself, you must:
  • be a graduate or undergraduate full-time student
  • have conducted the majority of the work to be presented
  • submit your abstract online by the deadline
  • be the submitting author and select “Yes” when asked if you are a full-time student
  • select yourself as the speaker
  • under TOPIC selection, choose “Consider for Best Student Paper Award”
  • make the oral presentation
  • attend the competition onsite and present a 4-minute summary (see below).

Competition Judging and Requirements
Contributions submitted by graduate and undergraduate students are eligible, whether poster or talk. For the evaluation, the conference chairs and select members of the program committee will judge the students within a devoted oral session of the conference. Here, the students will present a brief summary of their oral or poster paper with a time limit of 4 minutes. Presentations will be judged based on content, scientific impact, organization, quality of presentation, answers to questions from the judging panel and audience members, and presenter's overall mastery of the subject. Candidates for the award need to be the presenting author, a full-time student, and must have conducted the majority of the research presented in the paper.
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Conference 11991

Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XXII

In person: 23 - 25 January 2022
All sponsors
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View Session ∨
  • 1: Biomedical Applications for Ultrafast Laser Systems I
  • 2: Biomedical Applications for Ultrafast Laser Systems II
  • 3: Ultrafast Lasers for Cell Manipulation
  • 4: Ultrafast Laser-Matter Interaction
  • 5: Novel Ultrafast Processing Techniques I
  • 6: Micromachining of Transparent Materials I
  • 7: Micromachining of Transparent Materials II
  • LASE Plenary and Hot Topics
  • 8: Novel Ultrafast Laser Sources
  • 9: Micromachining of Transparent Materials III
  • 10: Novel Characterization Techniques for Ultrashort Pulses
  • 11: Novel Ultrafast Processing Techniques II
  • Frontiers in Ultrafast Optics Best Student Presentation Competition and Award Ceremony


  • Submissions are accepted through 06-December
  • Notification of acceptance by 20-December

View Call for Papers PDF Flyer
Session 1: Biomedical Applications for Ultrafast Laser Systems I
Session Chair: Peter R. Herman, Univ. of Toronto (Canada)
Author(s): Donald R. Risbridger, Rainer J. Beck, Heriot-Watt Univ. (United Kingdom); Thomas I. Maisey, David Jayne, Univ. of Leeds (United Kingdom); Jonathan D. Shephard, Heriot-Watt Univ. (United Kingdom)
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Various beam shapes (including Bessel-Gauss beams) and laser scanning parameters have been investigated for plasma-mediated ablation of porcine intestinal tissue, capitalising upon the distinct advantages offered from applying ultrashort pulsed lasers to novel medical applications, including microsurgery. Ablation profiles were assessed through optical surface profilometry and histological analysis. If adopted in operating theatres, surgeons could benefit from increased precision when resecting neoplasia in the colon, providing greater levels of control both laterally and in the depth of tissue removed compared to current electrocautery methods.
Author(s): Laura Gemini, Samy Al-Bourgol, Guillaume Machinet, ALPhANOV (France); Raphaël Devillard, Serge Mordon, Aboubakr Bakkali, Bioingénierie Tissulaire, Univ. de Bordeaux (France); Marc Faucon, Rainer Kling, ALPhANOV (France)
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Femtosecond (fs) lasers are currently considered in the frame of next-generation high-resolution bone tissue thanks to their unique properties which ensure a drastic reduction of thermal loads into the irradiated tissue and an overall improved healing quality and duration. In this work, a deep experimental analyses of heat dynamics was carried by IR FLIR camera imaging and thermo-couple sensors. Results show that it is indeed possible to reach temperatures below the protein denaturation temperature of the bone when the fs laser processing is carried out in pressured-water spray environment. Finally, it is shown that LIBS technique is a valid technique for real time monitoring of bone condition and it allows discriminate health bone tissue from carbonized or calcined one during laser ablation.
Session 2: Biomedical Applications for Ultrafast Laser Systems II
Session Chair: Roberto Osellame, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Author(s): Marco Andreana, Medizinische Univ. Wien (Austria); Caterina Sturtzel, St. Anna Kinderkrebsforschung e.V., Innovative Cancer Models (Austria); Ming Yang, VIULASE GmbH (Austria); Richard Latham, Research Institute of Molecular Pathology (Austria); Rainer A. Leitgeb, Wolfgang Drexler, Medizinische Univ. Wien (Austria); Manuel Zimmer, Research Institute of Molecular Pathology (Austria); Tuan Le, VIULASE GmbH (Austria); Martin Distel, St. Anna Kinderkrebsforschung e.V., Innovative Cancer Models (Austria); Angelika Unterhuber, Medizinische Univ. Wien (Austria)
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A novel direct diode pumped femtosecond Kerr-lens-mode-locked Ti.sapphire oscillator scheme for nonlinear optical imaging is presented and characterized. The complexity, and by that the footprint and the cost of the laser are considerably reduced by the proposed scheme. The power, noise performance and beam quality are comparable with commonly used commercial ultrafast Ti:sapphire systems. The emission characteristic of the laser is set such as two-photon-excited fluorescence, second harmonic generation and coherent anti-Stokes Raman scattering are efficiently excited in a laser scanning microscope setup. Imaging capabilities are shown in vivo on small animal models of interest.
Author(s): Shaun A. Engelmann, Annie Zhou, Ahmed M. Hassan, Michael R. Williamson, Andrew K. Dunn, The Univ. of Texas at Austin (United States)
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Here we present a system including a diamond Raman laser and fiber amplifier with high value for imaging neural structure through multiphoton microscopy. Construction is both simple and cost-efficient, which makes it a great alternative to conventional ultrafast laser options. The produced wavelengths (λ=1060 nm, λ=1250 nm) efficiently excite many red-shifted neural labels, and the repetition rate (80 MHz) is compatible with fast scanning technologies that enable rapid image acquisition. We demonstrate our system’s utility through neuronal imaging, neurovascular imaging at deep locations (>1 mm), and longitudinal imaging over a large field of view aided by a resonant scanning strategy.
Author(s): Zi-Ping Chen, Lu-Ting Chou, Yu-Cheng Liu, Shih-Hsuan Chia, National Yang-Ming Univ. (Taiwan)
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We optimized the spectral coverage of self-phase-modulation-enabled femtosecond fiber sources by careful investigations into the influence of input pulse width, fiber length, and fiber damage, and we have demonstrated a widely tunable source ranging from 740-1250 nm for two-photon microscopy applications. In addition, tens of milliwatt tunable near-UV/visible spectrum is easily obtained by a frequency-doubled conversion, and the gap between the fundamental and frequency-doubled spectra can be filled with the nonlinear wave breaking around 650 nm. A multi-modality microscopy incorporating two-photon microscopy and confocal fluorescence microscopy was also demonstrated to prove the versatility of our development for biomedical imaging.
Session 3: Ultrafast Lasers for Cell Manipulation
Session Chair: Adela Ben-Yakar, The Univ. of Texas at Austin (United States)
Author(s): Yusuke Ito, The Univ. of Tokyo (Japan); David Veysset, Stanford Univ. (United States); Steven E. Kooi, Dmitro Martynowych, Massachusetts Institute of Technology (United States); Keiichi Nakagawa, The Univ. of Tokyo (Japan); Keith A. Nelson, Massachusetts Institute of Technology (United States)
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Laser-induced shock waves have been gaining attention for biological and medical applications in which shock waves influence cell permeation. However, the mechanisms of permeation remain mostly unclear because of the difficulty of observing the transient and dynamic behaviors of the shock waves and the cells. Here we present an all-optical measurement method that can quantitatively capture the pressure distribution of the propagating shock wave and simultaneously monitor the dynamic behavior of cell membranes. Using this method, we find that a sharp pressure gradient causes cell membrane permeation. Our measurement will further advance biological and medical applications of shock waves.
Author(s): Alain Abou Khalil, Lab. Hubert Curien (France); Steve Papa, Univ. de Lyon (France), Univ. Jean Monnet Saint-Etienne (France), SAINBIOSE (France); Nicolas Compère, Alina Pascale Hamri, Manutech USD (France); Alain Guignandon, Univ. de Lyon (France), SAINBIOSE (France); Virginie Dumas, Ecole Nationale d'Ingénieurs de Saint-Etienne (France), Lab. de Tribologie et Dynamique des Systèmes (France); Xxx Sedao, Lab. Hubert Curien (France)
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Titanium based dental implant suffer sometimes from failure due to lack of osseointegration in the jaw bone. In this work, we study the generation of Laser Induced Periodic Structures (LIPSS) using three different femtosecond lasers with wavelengths of 1030,515 & 257nm. Fully covered Titanium alloy (Ti6AlV) samples with different LIPSS periodicities are produced and wettability tests are performed prior and post sterilization of the samples. Finally, a comparison between the effect of different LIPSS on the cell adhesion is performed using mesenchymal stem cells to identify the best pattern for enhanced cell adhesion.
Session 4: Ultrafast Laser-Matter Interaction
Session Chair: Peter R. Herman, Univ. of Toronto (Canada)
Author(s): Olga Koritsoglou, Aix-Marseille Univ. (France); Olivier Thomine, Olivier Utéza, David Grojo, CNRS (France); Didier Loison, Univ. de Rennes 1 (France); Alexandros Mouskeftaras, CNRS (France)
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In this study, we investigate the conversion of femtosecond laser energy deposition from plasma into a shockwave in ambient air. The experiments are carried out using a 380fs pulsed laser at 1.03μm, with laser intensities below the filamentation threshold. The measurements of this dynamic phenomenon are carried out with the help of a time-resolved transmission microscope, and the pressure and temperature space-time evolution are evaluated using a theoretical model. In our conditions we generate shockwaves with initial pressure loading in the range of GPa and maximum propagation velocity in the order of a few km/s.
Author(s): Justinas Pupeikis, Benjamin Willenberg, ETH Zurich (Switzerland); Francois Bruno, Univ. de Bordeaux (France); Mike Hettich, Research Ctr. for Non Destructive Testing GmbH (Austria); Alexander Nussbaum-Lapping, Matthias Golling, Carolin P. Bauer, Sandro L. Camenzind, ETH Zurich (Switzerland); Benayad Abdelmjid, Patrice Camy, Ctr. de Recherche sur les Ions, les Matériaux et la Photonique, Univ. de Caen Normandie (France); Bertrand Audoin, Univ. de Bordeaux (France); Christopher R. Phillips, Ursula Keller, ETH Zurich (Switzerland)
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We present a free-running 80-MHz polarization-multiplexed solid-state dual-comb laser which delivers 1.8 Watts of average power with 110-fs pulse duration per comb. We apply this free-running dual-comb laser to picosecond ultrasonic measurements via a high-sensitivity pump-probe setup. We demonstrate ultrasonic measurements on thin-film samples, and compare our measurements to ones obtained with a pair of locked femtosecond lasers and x-ray diffraction measurements. Our data show that a free-running dual-comb laser is well-suited for picosecond ultrasonic measurements and thus it offers significant reduction in complexity and cost for this widely adopted non-destructive testing technique.
Author(s): Kaneto Tsunemitsu, Keio Univ. (Japan); Akira Watanabe, Institute of Multidisciplinary Research for Advanced Materials, Tohoku Univ. (Japan); Hiroaki Onoe, Mitsuhiro Terakawa, Keio Univ. (Japan)
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We demonstrate the fabrication of double-network (DN) hydrogel microstructures inside a hydrogel by multi-photon cross-linking induced by focused femtosecond laser pulses. Two different poly(ethylene glycol) diacrylate (PEGDA, Mw=700 and 4000) solutions were prepared. A cross-linked PEGDA hydrogel molded into block-shape was immersed in PEGDA hydrogel prepolymer solutions of different molecular weight. Then the DN microstructures were fabricated by spatially-selective photo cross-linking of the polymer chains by femtosecond laser pulse irradiation. The mechanical strength of DN microstructures were enhanced which was confirmed by uniaxial compression test, suggesting the potential of our method for controlling spatial distribution of strength and stiffness.
Session 5: Novel Ultrafast Processing Techniques I
Session Chair: Roberto Osellame, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Author(s): Ronan McCann, Abhijit S. Cholkar, David Kinahan, Dermot Brabazon, Dublin City Univ. (Ireland)
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As manufacturers seek to move to sustainable materials, aluminum has seen a resurgence of interest. Ultrafast laser processing offers one route towards further extending the native capabilities and functionalities of this material. In this work we examine the use of a low-power (<4 W) 400 fs laser system for surface nano- and microstructuring of aluminum alloys 6061 and 7075. Changes in surface morphology and hydrophobicity were investigated, along with the corrosion behavior of the processed surfaces. As scalability is of paramount importance in industrial contexts, the use of scanning optics and spatial light modulation for large-area processing were also assessed.
Author(s): Eric Audouard, Benoit Tropheme, Julien Pouysegur, Florent Basin, Jorge Sanabaria, Julien Nillon, Martin Delaigue, Clemens Hönninger, Eric Mottay, Amplitude (France); Girolamo Mincuzzi, Marc Faucon, Rainer Kling, ALPhANOV (France)
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Femtosecond technologies will enable new fields of use and new methods of production thanks to the "agility" of high-power fs lasers associated with beam engineering. The relative slowness of the removal processes in femtosecond mode is no longer a limitation and the unique quality of ultra-short processes is therefore accessible to an increasingly important panel of industrial implementation. We report on the versatile use of femtosecond pulses at more than 300W average power at a wavelength of 1030 nm, 200W at 515nm, and 100W at 343 nm, free triggering of the laser output pulses, and burst generation.
Author(s): Ivan Gusachenko, Clément Jacquard, CAILabs (France); Benoít Beaudou, Pierre Guay, GLOphotonics (France); Gwenn Pallier, Guillaume Labroille, CAILabs (France); Fetah Benabid, GLOphotonics (France)
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Micro processing applications using femtosecond lasers have developed thanks to the quality of the process. A challenge still to be addressed is the capability to deliver the beam through a fibre. One solution is the use of hollow-core inhibited coupling fibres, nevertheless its use requires a beam stabilization to insure a stable operation. This study attempts to qualify two beam stabilisation systems: two piezo motors coupled with four quadrant detectors and Cailabs’ all-optical mode-cleaner system based Multi-Plane Light Conversion (MPLC) technology. To do such output fibre transmission efficiency and beam quality are investigated under controlled fluctuation of beam pointing.
Session 6: Micromachining of Transparent Materials I
Session Chair: Adela Ben-Yakar, The Univ. of Texas at Austin (United States)
Author(s): Roberto Memeo, Andrea Crespi, Politecnico di Milano (Italy); Roberto Osellame, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
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We present a way to exploit 3D resonant mechanical micro-structures, embedded in glass substrates, to achieve optical signals switching at MHz frequency. These structures are realised by means of femtosecond laser pulses: combining direct waveguide writing and laser-assisted etching in hydrofluoric acid of the 3D microstructure. The mechanical oscillation of the resonator induces periodical refractive index modifications, due to localised stress, across the waveguide region, thus modulating the phase of the propagating optical signal.
Author(s): Enrico Casamenti, Sacha Pollonghini, Yves Bellouard, Ecole Polytechnique Fédérale de Lausanne (Switzerland)
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In this study, we investigate multiple etchants and laser parameters. Interestingly, we show that there is an optimal energy dose one order of magnitude smaller than the currently used ones, and notably, at a regime where nanogratings are not yet formed. This energy dose yields higher process efficiency and lower processing time, and this, with unprecedented aspect ratio levels. We further demonstrate that for low dose exposure is the formation of laser-induced bond matrix defects in the glass matrix and not the presence of nanogratings that drives the etching selectivity.
Author(s): Francesca Bragheri, Petra Paiè, Francesco Ceccarelli, Matteo Calvarese, CNR-Istituto di Fotonica e Nanotecnologie (Italy); Roberto Osellame, CNR-Istituto di Fotonica e Nanotecnologie (Italy), Politecnico di Milano (Italy), Politecnico di Milano (Italy); Andrea Bassi, Politecnico di Milano (Italy); Federico Sala, Politecnico di Milano (Italy), CNR-Istituto di Fotonica e Nanotecnologie (Italy)
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Integrated optical modulators allow performing reconfigurability in circuits, resulting as fundamental components in different fields ranging from optical communications to sensing and metrology. Thermo-optic effect has been exploited to fabricate optical modulators by femtosecond laser micromachining (FLM) in glass substrates. In this work, we present an integrated optical switch realized by FLM with a switching time of less than 100 μs: about two orders of magnitude shorter than conventional switches realized by FLM. The result has been achieved by carefully optimizing the geometry and the position of resistors and trenches near the waveguides through simulation and experimental validation.
Session 7: Micromachining of Transparent Materials II
Session Chair: Peter R. Herman, Univ. of Toronto (Canada)
Author(s): Laura Loi, Ctr. Lasers Intenses et Applications, Univ. de Bordeaux (France); Théo Guérineau, Institut de Chimie de la Matière Condensée de Bordeaux, Univ. de Bordeaux (France); Sylvain Danto, Thierry Cardinal, Yannick Petit, Institut de Chimie de la Matière Condensée de Bordeaux, Univ. de Bordeaux (France); Lionel Canioni, Ctr. Lasers Intenses et Applications, Univ. de Bordeaux (France)
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We report on high refractive index change up to 10^-2 in silver-containing glasses by means of subsequent multiscan femtosecond laser inscription.
This technique is based on cumulative pulses absorption and it takes benefit of type A modification peculiarity to maintain an athermal regime, allowing for the absorption of an high number of pulses without inducing any thermal effect. Such remarkably high refractive index contrast is exploited to fabricate type A waveguides, such as bended waveguides in order to achieve compact devices for photonics applications.

Author(s): Hossein Mahlooji, Abdullah Rahnama, Gligor Djogo, Fae Azhari, Peter R. Herman, Univ. of Toronto (Canada)
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A point-by-point femtosecond laser fabrication technique was used to form filament arrays inside single-mode telecommunication fiber. The off-axis positioning of the grating from the neutral axis was key to enabling displacement optical sensing in single mode fiber. Optomechanical responses were enhanced with stress concentration in cantilevered optical fiber. The narrow geometry of the filament array facilitated sensing of a uniform strain field induced by the lateral displacement, or to null the response when filaments were orthogonally oriented. In this way, filament gratings could be overlaid for azimuthally resolved displacement sensing. The ability to measure transverse displacements paves the way toward developing more efficient optical accelerometers.
Author(s): Olivier Bernard, Andrea Kraxner, Assim Boukhayma, Ecole Polytechnique Fédérale de Lausanne (Switzerland); Jeff Squier, Colorado School of Mines (United States); Christian Enz, Yves Bellouard, Ecole Polytechnique Fédérale de Lausanne (Switzerland)
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Tightly focused femtosecond exposure of bulk transparent materials induces several types of atomic level defects, and nano- to micro-scale structural changes. The nature of the modification is dependent on the material, and on exposure parameters. Perturbations hinder the quality of the process, as it is performed in open-loop control because of the lack of in situ monitoring methods. Because of the sub-diffraction limit patterns and quasi-isorefractive nature of most modifications, observing through conventional microscopy is not achievable. Here, we propose using wide-field third-harmonic generation microscopy to image the modified areas, a method that enhances optical heterogeneities, to identify patterns.
LASE Plenary and Hot Topics
In person: 24 January 2022 • 3:30 PM - 6:00 PM
More information available soon!
Session 8: Novel Ultrafast Laser Sources
Session Chair: Roberto Osellame, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Author(s): Philipp Täschler, Mathieu Bertrand, Barbara Schneider, Matthew Singleton, ETH Zurich (Switzerland); Pierre Jouy, IRsweep AG (Switzerland); Filippos Kapsalidis, Mattias Beck, Jérôme Faist, ETH Zurich (Switzerland)
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The quantum cascade laser has evolved to be a compact, powerful source of coherent mid-infrared light. However, its fast gain dynamics strongly restricts the formation of ultrashort pulses. Here, we demonstrate an approach capable of producing near-transform-limited femtosecond pulses. Starting from a frequency modulated phase-locked state, which most efficiently exploits the gain of the active region, ultrashort pulses are generated via external pulse compression. We assess their temporal nature by means of a novel upconversion sampling method, coherent beat note interferometry and interferometric autocorrelation. These results open new pathways for nonlinear physics in the mid-infrared.
Author(s): Steffen Hädrich, Maxim Tschernajew, Active Fiber Systems GmbH (Germany); Evgeny Shestaev, Active Fiber Systems GmbH (Germany), Abbe Ctr. of Photonics, Friedrich-Schiller-Univ. Jena (Germany); Fabian Stutzki, Nico Walther, Florian Just, Florian Karl, Sven Breitkopf, Christian Gaida, Oliver Herrfurth, Active Fiber Systems GmbH (Germany); Imre Seres, Zsolt Bengery, Barnabas Gilicze, Péter Jójárt, Zoltán Várallyay, Ádám Börzsönyi, ELI-ALPS Research Institute, ELI-HU Nonprofit Ltd. (Hungary); Michael Müller, Friedrich-Schiller-Univ. Jena (Germany); Christian Grebing, Friedrich-Schiller-Univ. Jena (Germany), Fraunhofer-Institut für Angewandte Optik und Feinmechanik IOF (Germany); Dominik Hoff, Single Cycle Instruments (Germany); Gerhard G. Paulus, Helmholtz Institute Jena (Germany), Friedrich-Schiller-Univ. Jena (Germany); Tino Eidam, Active Fiber Systems GmbH (Germany); Jens Limpert, Active Fiber Systems GmbH (Germany), Abbe Ctr. of Photonics, Friedrich-Schiller-Univ. Jena (Germany), Fraunhofer-Institut für Angewandte Optik und Feinmechanik IOF (Germany)
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We present a sub-2-cycle laser system combining high average power, pulse energy and repetition rate with CEP-stable operation. The laser system creates 300 fs pulses with 1.8 mJ pulse energy that are nonlinearly post-compressed down to few optical cycles in two subsequent multipass cells (MPC). A pulse duration of 5.8fs (sub-2-cycle) at a pulse energy of 1.1mJ in combination with 110W average power (100 kHz) is achieved. This corresponds to the shortest pulses and highest compressed average power for few-cycle MPCs. Furthermore, the carrier-to-envelope-phase stability amounts to 300 mrad for frequencies above 2 kHz as measured by stereo—above-threshold-ionization (ATI).
Author(s): Eric Audouard, Julien Pouysegur, Vincent Gruson, Martin Delaigue, Denis Ferachou, Julien Loyez, Eric Mottay, Clemens Hönninger, Amplitude (France)
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We report on kW-level femtosecond lasers for flexible and high throughput industrial applications. Power scaling is achieved by a slab-based amplifier architecture. The laser concept is capable to generate high pulse energies in the multi-mJ range as well as high pulse repetition rates in the MHz or GHz ranges. Moreover, free triggering (FemtoTrig®) and burst options as well as frequency conversion to the green and UV spectral region will leverage these femtosecond lasers into future industrial applications.
Author(s): Antoine Delgoffe, Saood Nazir, Sargis Hakobian, Ecole Polytechnique Fédérale de Lausanne (Switzerland); Clemens Hönninger, Amplitude (France); Yves Bellouard, Ecole Polytechnique Fédérale de Lausanne (Switzerland)
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We report on a new concept of credit card-sized free-space Yb:KYW laser cavity designed to generate femtosecond pulses at a GHz repetition-rate. Optical components are assembled directly, without mounts, inside slots fabricated by direct laser writing and chemical etching in a rigid fused-silica substrate, ensuring a very precise pre-alignment. In this concept, the alignment fine-tuning is provided by one-time actuators fabricated within the glass substrate itself and which are remotely activated using femtosecond laser-induced micro-deformation in the bulk of the substrate. As first proofs of concept, efficient CW and SESAM-enabled passive mode-locking regimes are demonstrated in prototype versions.
Author(s): Florian Emaury, Benjamin Rudin, Menhir Photonics AG (Switzerland)
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Ultrafast lasers are key tools for micromachining and medical applications, but also in a growing numbers of domains like telecoms, aerospace and microwave photonics, which are currently limited by the lack of reliability of the lasers and the achievable repetition rate. Menhir Photonics has now successfully demonstrated and deployed real-turnkey ultrafast laser oscillators at 1.5 um and GHz repetition rate with an unprecedent robustness. Reaching now up to 2.5 GHz of fundamental repetition rate and the lowest phase noise and timing jitter on the market, the MENHIR-1550 was already qualified for Space. The latest development of the MENHIR-1550 at 2.5 GHz will be presented (first commercial product of its kind) as well as the newest applications that it enabled worldwide, in the fields of green-house gases monitoring from Space, very fast dual-comb spectroscopy or photonics analog-to-digital converter.
Session 9: Micromachining of Transparent Materials III
Session Chair: Adela Ben-Yakar, The Univ. of Texas at Austin (United States)
Author(s): Myriam Kaiser, Marvin Feil, Michael Lang, Max Kahmann, Jonas Kleiner, Daniel Flamm, TRUMPF Laser- und Systemtechnik GmbH (Germany)
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We report on the separation of glass substrates with edge contours in C-shape. To achieve single-pass laser modifications along the entire contour geometry a processing optics is presented where a multitude of foci are simultaneously distributed inside a working volume. Tangential angles of the focus trajectory to the surface can be almost arbitrarily chosen and amount to even less than 45-deg. After having induced laser modifications along the desired edge geometry, separation is done chemically in the present case. The glass articles, thus fabricated, meet the demands of the display industry in terms of bending strength and surface quality.
Author(s): Keyou Chen, Feng Feng, TRUMPF China Co., Ltd. (China); Felix Zimmermann, Jonas Kleiner, Daniel Flamm, TRUMPF GmbH & Co. KG (Germany)
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We report on the design and realization of novel non-diffracting beams for ultrashort laser materials processing. Our method is axicon based and introduces subtle azimuthal modifications to the conical lenses or well-defined misalignments to achieve a set of novel non-diffracting beams. These focus distributions retain all well-known advantages of non-diffracting beams, such as self-healing, high optical efficiency, or possible extreme aspect ratios. Additionally, tailored transversal intensity profiles with, for example, well-defined preferential direction can be generated. Clear advantages for controlling residual stress and crack orientation in glass processing are discussed and micro machining experiments ranging from cutting to welding are presented.
Author(s): Jason R. Grenier, Lars A. Brusberg, Chad C. Terwilliger, Kristopher A. Wieland, Corning Research & Development Corporation (United States)
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As on-board and co-packaged optics propose significant advancements for next-generation data center switches, the high-volume manufacturing of the photonic integrated circuits that underpin the technology will be required. A major challenge of yielding vertical end-facets with the optical quality needed for low-loss coupling to single-mode fibers is overcome by using an ultrashort pulsed laser with quasi-non-diffracting beams to singulate the optical circuits while leaving optical quality regions around both planar ion-exchanged and buried 3D laser-inscribed waveguides. This technique is applied to multi-project wafers comprised of free-form optical circuits with complex layout patterns and to wafers with hundreds of optical circuits, and thus paves the way towards a high-volume manufacturing solution.
Session 10: Novel Characterization Techniques for Ultrashort Pulses
Session Chair: Peter R. Herman, Univ. of Toronto (Canada)
Author(s): Jacob Stamm, Marcos Dantus, Michigan State Univ. (United States)
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We present a pulse-shaper based method to measure and correct arbitrary spectral phase distortions to milliradian precision in broadband femtosecond laser pulses. The method involves scanning a pi/2 phase step across the spectrum of the pulse and recording the second harmonic generation spectrum. Information about the phase is obtained through the pi/2 step vs SHG contour map. Several types of arbitrary spectral phases from optics and by a pulse shaper are added to the pulse and retrieved again using the pi/2-scan method. The accuracy and limitations of the retrieval method across the studied phase types are discussed.
Author(s): Matthias Baudisch, Mateusz Ibek, Edlef Büttner, Peter Staudt, APE Angewandte Physik & Elektronik GmbH (Germany)
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We propose Type-II SHG-autocorrelation as a simple and robust tool for high-dynamic range pulse-contrast measurements of sub-μJ energy, high-repetition rate pulses. We demonstrate dynamic ranges of the autocorrelation of over 10^7 with input energies of 55 nJ at 1 MHz repetition rate. The device allows temporal resolutions of 25 fs over a wide scanning range of 1100 ps, supporting input wavelengths from 700-1200 nm. The technique provides the perfect tool for wide use pulse-contrast measurement and optimization, possibly enabling a more effective use of pulse energy in peak power driven material processing applications.
Author(s): Lakshmi C. G., V.R. Supradeepa, Ctr. for Nano Science and Engineering (CeNSE) (India)
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Ultrashort pulse sources are complex and resource-intensive. Robust delivery of pulses to time-varying satellite locations reduces overhead. This requires accurate characterization of the delivered pulses remotely without specialized equipment. We demonstrate a compact measurement method with power detectors at the fundamental and second harmonic wavelengths and a thin SHG crystal. At the source, a pulse shaper-based interferometer creates pulse pairs with varying time delays. Together, they provide the field autocorrelation (related to spectra) and the intensity autocorrelation. Pulse parameters obtained following 50m of propagation in an existing fiber link of a sub-picosecond source matched well with direct measurements.
Session 11: Novel Ultrafast Processing Techniques II
Session Chair: Roberto Osellame, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Author(s): Gözden Torun, Anastasia Romashkina, Ecole Polytechnique Fédérale de Lausanne (Switzerland); Tetsuo Kishi, Tokyo Institute of Technology (Japan); Yves Bellouard, Ecole Polytechnique Fédérale de Lausanne (Switzerland)
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Tellurite glasses combine a wide optical transmission window up to 5 µm with a high refractive index and nonlinear optical properties, making them attractive materials for photonic applications. We demonstrated that, upon near-IR femtosecond (fs) laser exposure the tellurite glass evolves into a functional metalloid/glass composite, due to a localized laser-induced elemental decomposition and a crystallization of a metalloid tellurium (Te). Here, we report on the electrical and photo-response characterization of Te micro-wires produced by fs laser direct-exposure of a tellurite glass. The fs laser direct writing offers interesting opportunities for investigating, not only photoconductivity, but also thermoelectricity and piezoelectricity of integrated glass/metalloid composites as future functional devices obtained without adding any other materials and through a high-precision single process.
Author(s): Daewoon Seong, Deokmin Jeon, Kyungpook National Univ. (Korea, Republic of); Ruchire Eranga Wijesinghe, Univ. of Sri Jayewardenepura (Sri Lanka); Kibeom Park, Ulsan National Institute of Science and Technology (Korea, Republic of); Hye Ree Kim, Euimin Lee, Mansik Jeon, Jeehyun Kim, Kyungpook National Univ. (Korea, Republic of)
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The improvement of the imaging speed of optical coherence tomography (OCT) has been widely studied. To enhance the speed of spectral-domain OCT (SD-OCT), we presented space-time division multiplexing (STDM)-based superfast SD-OCT with 1 MHz A-scan rate. Two cameras for time-division multiplexing (TDM) were implemented in the single spectrometer to fully utilize the operating time. In addition, the optical path length difference of the two scanners is precisely controlled to apply the space-division method (SDM). In this paper, we successfully integrated the TDM and SDM simultaneously and its applicability was demonstrated by inspection of the optical thin film.
Frontiers in Ultrafast Optics Best Student Presentation Competition and Award Ceremony
In person: 25 January 2022 • 5:00 PM - 6:00 PM
Competition . . . . . . . . . . . . . . . 5:00 PM to 5:45 PM
Judging & Award Ceremony . . . 5:45 PM to 6:00 PM

We are pleased to announce that cash prizes will be awarded to the best student presentations in this conference (1st, 2nd, and 3rd place; both poster and oral papers considered).

Papers submitted and presented by graduate and undergraduate students are eligible. In order to ensure a fair evaluation, the conference chairs and the program committee will judge the students during a special student competition session held during the conference. Here the students present a brief 4-minute summary of their original talk or poster presented at the conference.

Following the student competition, the judges will meet and decide on the winner. The winners will be announced during the award ceremony and awarded a cash prize.

Award sponsored by:
Conference Chair
Univ. of Toronto (Canada)
Conference Chair
CNR- Istituto di Fotonica e Nanotecnologie (Italy)
Conference Chair
The Univ. of Texas at Austin (United States)
Program Committee
Princeton Univ. (United States)
Program Committee
Ecole Polytechnique Fédérale de Lausanne (Switzerland)
Program Committee
TRUMPF Laser- und Systemtechnik GmbH (Germany)
Program Committee
Leibniz Univ. Hannover (Germany)
Program Committee
Univ. of California, Davis (United States)
Program Committee
Harvard Univ. (United States)
Program Committee
Amplitude Systèmes (France)
Program Committee
Berner Fachhochschule Technik und Informatik (Switzerland)
Program Committee
Friedrich-Schiller-Univ. Jena (Germany)
Program Committee
Technische Univ. Wien (Austria)
Program Committee
Cornell Univ. (United States)
Program Committee
Instituto de Óptica "Daza de Valdés" (Spain)
Program Committee
RIKEN Ctr. for Advanced Photonics (Japan)
Program Committee
Keio Univ. (Japan)
Program Committee
Univ. of Lübeck (Germany)
Program Committee
Technion-Israel Institute of Technology (Israel)
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