Schawlow-Townes Symposium on Photonics
October 13, 2022
The University of Ottawa established the Schawlow-Townes Symposium on Photonics in 2012, in honour of Arthur L. Schawlow and Charles H. Townes, recognized as the pioneers of laser technology. This annual symposium aims to bring to light the research and discoveries of photonics experts in Canada and around the world.
Join us in person or online to learn about the latest developments from internationally recognized researchers.
All times are Eastern Daylight Time.
8:30 a.m. Registration & Networking Breakfast
9:15 a.m. Welcome and Opening Remarks
9:45 a.m. Broadband Quantum Memories: From Protocols to Platforms
Presented by Duncan England (National Research Council of Canada)
10:45 a.m. Attosecond Interferometry
Remote Presentation by Nirit Dudovich (Weizmann Institute of Science)
11:45 a.m. Poster Session & Lunch
1:45 p.m. Imaging at the speed of light
Presented by Jonathan Leach (Heriot-Watt University)
2:45 p.m. Computational Microscopy: Coherent Diffractive Imaging with Photons and Electrons
Remote Presentation by John Miao (University of California, Los Angeles)
3:40 p.m. Program Break
3:55 p.m. Extreme nonlinear fibre optics
Presented by Francesco Tani (Max Planck Institute for the Science of Light)
4:50 p.m. Closing Remarks
5 p.m. End
N.B.: Sessions marked in bold are available for online participants.
Weizmann Institute of Science (Israel)
Attosecond science is a young field of research that has rapidly evolved over the past decade. One of the most important aspect of attosecond spectroscopy lies in its coherent nature. Resolving the internal coherence is a primary challenge in this field, serving as a key step in our ability to reconstruct the underlying dynamics. As in many other branches in physics, coherence is resolved via interferometry. In my talk, I will describe advanced schemes for attosecond interferometry. The application of these schemes provides direct insights into a range of fundamental phenomena in nature, from tunneling and photoionization in atomic systems to ultrafast chiral phenomena and attosecond scale currents in solids.
The first part of my talk will be dedicated to the study of one of the most fundamental strong field phenomena – field induced tunnel ionization. Applying an all-optical interferometry resolved the barrier’s modifications during the tunneling mechanism as well as the excitation of the electron as it propagates under the tunneling barrier. Interferometry can be induced in the spatial domain as well. By shaping of 2D electron trajectories, we have induced a microscopic spatial interferometer, and probed the spatial properties of molecular systems. Finally, we have applied attosecond interferometry to explore subcycle dynamics in condense matter systems, resolving field induced band gap dynamics or probing the Berry phase accumulated during the strong field interaction.
National Research Council of Canada
Broadband Quantum Memories: From Protocols to Platforms
Quantum memories – devices that can store single photons and retrieve them on demand – are expected to be a key enabling component in long-distance ground-based quantum communications. Beyond their conventional use in quantum repeaters, various unconventional applications of quantum memories have been proposed to enhance quantum processing and sensing protocols. In this talk, I will describe the broadband quantum memories developed at NRC over the past decade. I will introduce two different protocols by which we store photons: Raman scattering and switched intra-cavity frequency translation (SWIFT). As well as the different platforms that we use: bulk diamond and fiber-based optical cavities. These memories can store short pulses of light (100 femtoseconds to 10 picoseconds), for a modest amount of time (10 picoseconds to 10 microseconds) so are more appropriate for the aforementioned unconventional applications. I will describe early progress towards realising these applications including quantum frequency conversion and beam splitter-type operations, which can both be performed while the photon is being stored.
Heriot-Watt University (Scotland)
Imaging at the speed of light
Single-photon detector array technologies have advanced significantly in recent years. Cameras now exist that are not only sensitive to single photons but the individual pixels in the sensor provide photon time-of-arrival information at the picosecond regime. Such unprecedented sensitivity and temporal resolution open up a number of exciting new applications, such as light-in-flight imaging, looking around corners with laser echoes, seeing through dense scattering media, and ultra-fast three-dimensional imaging. I will discuss the recent developments of the camera technology and discuss our latest results. I will give details of our latest results on 3D human pose estimation from low-resolution single-photon detectors via neural networks with a future outlook to person re-identification methods.
University of California, Los Angeles (United States)
Computational Microscopy: Coherent Diffractive Imaging with Photons and Electrons
Since the invention of compound microscopes in the 17th century, lens-based microscopy, such as optical, phase-contrast, fluorescence, confocal, super-resolution, and electron microscopes, has played an important role in the evolution of modern science and technology. In 1999, a novel form of microscopy, known as coherent diffractive imaging (CDI), lens less or computational microscopy, was developed to transform our conventional view of microscopy, in which the physical lens of a microscope was replaced by a computational algorithm. The well-known phase problem was solved by oversampling with iterative algorithms. CDI methods such as plane-wave CDI, ptychography (i.e., scanning CDI) and Bragg CDI have since been implemented for a wide range of applications in the physical and biological sciences using synchrotron radiation, X-ray free electron lasers, high harmonic generation, optical and electron microscopy. In this talk, I will present some recent methodology developments of this rapidly growing field and highlight several important cross-disciplinary applications.
Max Planck Institute for the Science of Light (Germany)
Extreme nonlinear fibre optics
Gas-filled hollow-core waveguides bring together nonlinear fibre optics and high-field laser science, thus providing access to novel nonlinear dynamics, new powerful tools for manipulating ultrashort light pulses, and enhanced light-matter interaction. The broadband transmission, the weak dispersion and the high-damage threshold allow guiding of extremely short and intense laser pulses and excellent control over their nonlinear propagation dynamics. Harnessing these enables the development of novel light sources with up to PHz bandwidths in spectral regions otherwise not easily accessible. Furthermore, the high efficiency and the low-pulse energy requirements of these processes facilitate the scaling of these sources to unprecedently high repetition rates, paving the way to the realization of dual-frequency combs in exotic spectral ranges.
In this talk, I will introduce the properties of gas-filled hollow-core fibres (HCFs) and soliton dynamics in such a system, then discuss photoionization-induced effects, HCF-based sources and future challenges.