Chairs
Professor Ruth Oulton, University of Bristol, UK
Professor Ruth Oulton, University of Bristol, UK
Ruth Oulton’s field of research involves the study of nanoscale semiconductor devices that enable the exchange of “quantum” information between a single electron and a single photon. The idea is that they can use the rules of quantum mechanics to perform computing and measurements in a completely new way. She take ideas from quantum theory and information science, bring them together with what we are beginning to understand about semiconductors on the nanoscale, and to make working quantum devices that engineers will use as part of their everyday toolkit. In her recent work she studies single electron spins in atomic-like systems, and studies how the angular momentum of the photon and spin exchange information, and how photonic design can influence this. In other interdisciplinary side projects she studies the role of photonic structures in plants such as seaweed and begonias.
13:30-14:00
Manipulating the character and shape of ultrashort quantum light states
Dr Marco Bellini, National Institute of Optics (CNR-INO), Italy
Abstract
A fully controlled state and mode engineering of nonclassical light is one of the major challenges in the path of future quantum technologies.
In recent years, quantum state engineering has quickly evolved, with new tools and techniques, such as photon addition and subtraction, which have demonstrated their extreme versatility for performing operations normally unavailable in the realm of Gaussian quantum optics. While photon subtraction can enhance nonclassicality and entanglement in a quantum light state, photon addition has the unique capability of creating nonclassicality and entanglement from scratch, whatever the input. However, engineering quantum states in a single, well-defined, mode is rarely enough. In real experiments, states are often prepared in modes that do not coincide with those used for their processing and detection, or for the optimal coupling to matter systems. Gaining access to the rich mode structure of quantum light would also greatly increase the capacity of communicating, manipulating, and storing quantum information. For all these tasks, and for those related to possible spectroscopic applications of nonclassical light, it is of fundamental importance to gain a full control over the modes that host the quantum states. In this talk, I will briefly present some of our recent experimental results towards the controlled generation, manipulation, and detection of the quantum state and mode structure of ultrashort light wavepackets.
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Dr Marco Bellini, National Institute of Optics (CNR-INO), Italy
Dr Marco Bellini, National Institute of Optics (CNR-INO), Italy
Marco Bellini is a Research Director at the Istituto Nazionale di Ottica (CNR-INO) in Florence, Italy. Although his main current interests are in the field of Quantum Optics, in the course of his scientific career he has been involved in very different experimental activities, ranging from high-precision atomic and molecular spectroscopy in the far infrared, to coherent sources in the extreme ultraviolet. He is an expert in frontier experimental research with ultrashort laser pulses, both in the regime of high-intensity laser-matter interactions, and in that of quantum effects with single-photon-level light intensities. Some of his main achievements were in the field of supercontinuum and high-order harmonic generation (his collaboration with Professor TW Hänsch contributed to the invention of the optical frequency comb and to the 2005 Nobel Prize in Physics), and in the production and characterization of nonclassical light states for fundamental tests.
14:15-14:45
Exploiting quantum correlations for spectroscopy, imaging and remote sensing
Professor John Rarity FRS, University of Bristol, UK
Abstract
In this talk I will review recent work on sensing technologies focussing on pair photon correlations applied to rangefinding and remote sensing. These experiments primarily exploit the time (energy) correlations between photons [1] and were recently popularised as quantum illumination [2]. I will review recent experimental results showing the possibility of 3D imaging and covert rangefinding using parametric pair photon sources. I will also review work towards practical photon limited gas sensing using near infra-red wavelengths [3] and extensions to longer wavelengths using non-linear interferometry [4] in bulk and chip scale experiments [5, 6].
[1] J.G. Rarity et al Applied Optics 29, 2939 (1990).
[2] S. Lloyd, Science 321, 1463 (2008).
[3] M Quatrevalet, JGR, et al, IEEE J. Selected Topics in Quantum Electronics 23, 157 (2017).
[4] T.J. Herzog, JGR et al Physical Review Letters, 72, 629 (1994).
[5] T. Ono, JGR et al, Optics letters 44 (5), 1277-1280 (2019).
[6] L. Rosenfield JGR et al arXiv:1906.10158.
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Professor John Rarity FRS, University of Bristol, UK
Professor John Rarity FRS, University of Bristol, UK
Professor John Rarity FRS is head of Quantum Engineering Technology Labs (Physics and E&EE) and Photonics Group (E&EE) at the University of Bristol (since 2003). He is an international expert on quantum optics, communications and sensing exploiting single photons and entanglement. He pioneered early experiments in path entanglement, quantum key distribution and quantum metrology. Current research focusses on non-linear waveguide sources of pair photons, integrated quantum photonics, sub-shot noise imaging schemes, long wavelength quantum sensing, free space quantum communications, multi-photon entanglement and nanocavities for spin photon interfaces.
15:30-16:00
Infrared metrology with visible light
Dr Leonid Krivitskiy, Agency for Science, Technology and Research (A*STAR), Singapore
Abstract
Infrared (IR) optical range is important for material characterization and sensing. Also, imaging in the IR range yields superior image contrast due to a significant reduction of scattering losses. Thus IR metrology is widely used in petrochemical, pharma, biomedical, homeland security, and other areas.
Even though there are well-developed conventional methods for IR metrology, the remaining challenges are associated with high cost, low efficiency and regulatory requirements for IR light sources and detectors. To mitigate these issues the team is developing new quantum-enabled techniques which allow them to retrieve properties of materials in the IR range from the measurements of visible range photons. The approach is based on the nonlinear interference of frequency correlated photons produced via spontaneous parametric down conversion (SPDC) [1, 2]. Within this process, one of the photons is generated in the visible range, and its correlated counterpart in the IR range is used to probe the properties of the medium. The visibility and phase of the observed fringes depend on the properties of the IR photon, which interacts with the sample. This allows the team to infer the properties of the sample in the IR range from the measurements of visible range photons. In a series of experiments, they demonstrate the IR spectroscopy [1-3], tunable optical coherence tomography (OCT) [4], and polarimetry [5]. In all these demonstrations the IR properties (absorption spectra, refractive index, 3D images, and polarization) are inferred from the measurements of the interference pattern in the visible range thus making IR measurements more affordable.
[1] D. Kalashnikov, A. Paterova, S. Kulik, L. Krivitsky, Nature Photonics 10, 98 (2016).
[2] A. Paterova, S. Lung, D. Kalashnikov, L. Krivitsky, Scientific reports 7, 42608 (2017).
[3] A. Paterova, H. Yang, Ch. An, D. Kalashnikov, L. Krivitsky, New Journal of Physics 20, 043015 (2018).
[4] A. Paterova, H. Yang, Ch. An, D. Kalashnikov, L. Krivitsky, Quantum Science & Technology 3, 025008 (2018).
[5] A. Paterova, H. Yang, C. An, D. Kalashnikov, L. Krivitsky, Opt. Express 27, 2589-2603 (2019).
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Dr Leonid Krivitskiy, Agency for Science, Technology and Research (A*STAR), Singapore
Dr Leonid Krivitskiy, Agency for Science, Technology and Research (A*STAR), Singapore
Leonid started his professional career in 2003 as a postdoctoral researcher at the National Metrology Institute (Turin, Italy). In 2005 he received Alexander von Humboldt fellowship and moved to Max Planck Institute for the Science of Light (Erlangen, Germany). In 2006 he received the H.C. Oersted fellowship at Technical University of Denmark (Lyngby, Denmark). In 2008 he started his group at Agency for Science Technology and Research (A*STAR) in Singapore being awarded A*STAR investigatorship grant. His research interests include quantum and nonlinear optics, quantum information processing, and quantum metrology. Leonid holds MSc and PhD degrees from Lomonosov Moscow State University and MBA degree from the National University of Singapore.
16:15-16:45
Single photon spectroscopy of atoms and solids
Dr Alex S Clark, Imperial College London, UK
Abstract
The absorption and reflection of light allows us to determine the properties of the world around us. Alex S Clark will present two recent experiments using single photons to perform absorption spectroscopy. The first uses photons generated by four-wave mixing in optical fiber. Two pump photons (~750nm) are annihilated to simultaneously generate time-correlated pairs of photons at widely spaced wavelengths (~650nm signal and ~900nm idler). The researchers tune the pump wavelength to scan idler photons across the absorption band-edge of gallium arsenide placed in the idler beam path. The transmission of the idler photons alone does not reveal the absorption due to overlapping Raman noise, but when correlated with detected signal photons, the absorption is revealed, a form of ‘ghost-spectroscopy’. The second experiment uses a bright pump laser to saturate rubidium atoms in a vapour cell, while a counter-propagating and cross-polarized single photon level probe reveals narrow transmission peaks corresponding to the hyperfine excited state energy levels of the atoms. The pump and probe are independently tunable, meaning atoms moving in all directions can be addressed by compensating the counter-propagating optical frequencies for the relevant Doppler shifts. This experiment forms a basis for building an atomic quantum memory.
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Dr Alex S Clark, Imperial College London, UK
Dr Alex S Clark, Imperial College London, UK
Dr Alex S Clark is a Royal Society University Research Fellow working on organic molecular quantum photonics at Imperial College London. He heads the Quantum Nanophotonics Project in the Centre for Cold Matter, is Work Package Leader on Interfaces in the EPSRC Programme Grant Quantum Science with Ultracold Molecules (QSUM) and leads a team working on coupling molecules to integrated waveguides and cavities in the QuantERA Consortium Organic Quantum Integrated Devices (ORQUID). His current research interests lie in the use of molecules to build new quantum technology and explore quantum science, including creating on-demand photon sources, quantum memories, photonic quantum gates and hybrid interfaces to link disparate quantum systems. Dr Clark has recently joined QUANTIC - the UK Quantum Hub for Imaging, in which he is working on imaging biological cells using induced coherence and nonlinear interferometry.
17:00-18:15
Poster session