My fields of expertise are Brillouin scattering and optomechanics, nonlinear fiber optics and photonic circuits, as well as classical and quantum communications. The projects in my group span from nonlinear optics to quantum optics with a focus on light-sound interactions and waveguide optomechanics. We want to explore optoacoustic interaction experimentally at the classical and quantum level with suitably engineered microstructured fibres and nanowaveguides to manipulate, in this way, light states
Spectrally pure microwave sources are highly desired for several<br> applications, ranging from wireless communication to next generation<br> radar technology and metrology. Additionally, to generate very pure<br> signals at even higher frequencies, these advanced microwave sources<br> have to be compact, low in weight, and low energy consumption to comply<br> with in-field applications. A hybrid optical and electronic cavity,<br> known as an optoelectronic oscillator (OEO), has the potential to<br> leverage the high bandwidth of optics to generate ultrapure<br> high-frequency microwave signals. Here we present a widely tunable, low<br> phase noise microwave source based on a photonic chip. Using on-chip<br> stimulated Brillouin scattering as a narrow-band active filter allows<br> single-mode OEO operation and ultrawide frequency tunability with no<br> signal degeneration. Furthermore, we show very low close-to-carrier<br> phase noise. This Letter paves the way to a compact, fully integrated<br> pure microwave source. (C) 2016 Optical Society of America
Attacks on practical quantum key distribution systems (and how to
prevent them)
Nitin Jain,
Birgit Stiller,
Imran Khan,
Dominique Elser,
Christoph Marquardt,
Gerd Leuchs
With the emergence of an information society, the idea of protecting sensitive data is steadily gaining importance. Conventional encryption methods may not be sufficient to guarantee data protection in the future. Quantum key distribution (QKD) is an emerging technology that exploits fundamental physical properties to guarantee perfect security in theory. However, it is not easy to ensure in practice that the implementations of QKD systems are exactly in line with the theoretical specifications. Such theory-practice deviations can open loopholes and compromise security. Several such loopholes have been discovered and investigated in the last decade. These activities have motivated the proposal and implementation of appropriate countermeasures, thereby preventing future attacks and enhancing the practical security of QKD. This article introduces the so-called field of quantum hacking by summarising a variety of attacks and their prevention mechanisms.
Efficient microwave to optical photon conversion: an electro-optical
realization
Alfredo Rueda,
Florian Sedlmeir,
Michele C. Collodo,
Ulrich Vogl,
Birgit Stiller,
Gerhard Schunk,
Dmitry V. Strekalov,
Christoph Marquardt,
Johannes M. Fink, et al.
Linking classical microwave electrical circuits to the optical telecommunication band is at the core of modern communication. Future quantum information networks will require coherent microwave-to-optical conversion to link electronic quantum processors and memories via low-loss optical telecommunication networks. Efficient conversion can be achieved with electro-optical modulators operating at the single microwave photon level. In the standard electro-optic modulation scheme, this is impossible because both up-and down-converted sidebands are necessarily present. Here, we demonstrate true single-sideband up-or down-conversion in a triply resonant whispering gallery mode resonator by explicitly addressing modes with asymmetric free spectral range. Compared to previous experiments, we show a 3 orders of magnitude improvement of the electro-optical conversion efficiency, reaching 0.1% photon number conversion for a 10 GHz microwave tone at 0.42 mW of optical pump power. The presented scheme is fully compatible with existing superconducting 3D circuit quantum electrodynamics technology and can be used for nonclassical state conversion and communication. Our conversion bandwidth is larger than 1 MHz and is not fundamentally limited. (C) 2016 Optical Society of America
Scientific career
since 2024 also W3 Full Professorship at Leibniz University Hannover
04/2019 – Independent Max Planck Research Group Leader (centrally funded, selected in the competitive call 2017), Max Planck Institute for the Science of Light, Germany, Quantum Optoacoustic
04/2021- 09/2022 Temporary W3 Full Professorship (Lehrstuhlvertretung), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Chair of Optics
06/2015 – 02/2019 Research fellow, The University of Sydney, CUDOS, Australia, Nonlinear Optical Phononics (Prof. Benjamin Eggleton)
10/2012 – 05/2015 Postdoctoral fellow, Max Planck Institute for the Science of Light, Germany, Optical Communication and Quantum Communication (Prof. Gerd Leuchs)
02/2012 – 09/2012Postdoctoral fellow, CNRS Institute FEMTO-ST, Besançon, France, Nonlinear Optics and Optoacoustics (Dr. Thibaut Sylvestre)
Academic education
01/2009 – 01/2012 Doctoral thesis, CNRS Institute FEMTO-ST, Besançon, France, “Brillouin scattering in photonic crystal fibre: from fundamentals to fibre optic sensors”, (Dr. Thibaut Sylvestre, Dr. Hervé Maillotte)
10/2003 – 12/2008 Master’s degree Mathematics / Physics / Education, University of Erlangen-Nuremberg, Germany, Master thesis: „Fabrication of periodically poled LiNbO3 for nonlinear optical frequency conversion by quasi phase matching“ (Prof. Jan-Peter Meyn, Prof. Christine Silberhorn)
Selected awards, fellowships, services
2024 - ERC Consolidator Grant
2024 - Henriette Hertz Scout of the Humbold Foundation
2019-2021 Conference chair, “Workshop on Optomechanics and Brillouin scattering - WOMBAT 2021/2022”, Erlangen, Germany (16-18 June 2021 and 14-17 June 2022)
2019 Conference chair, “Workshop on Optomechanics and Brillouin scattering - WOMBAT 2021”, Erlangen, Germany (planned for 16-18 June 2021)
2019 Guest editor for APL Photonics for the Topical Issue “Optoacoustics - Advances in High-Frequency Optomechanics and Brillouin Scattering”
2018 Co-Chair, “Nanophotonics 2018 – the next frontier”, Canberra, Australia
2016 Co-Chair, “Quantum photonic connections conference”, Sydney, Australia
2013 – 2015 Cusanuswerk career development program
2011 Prix A’Doc 2011 of the Université Franche-Comté
2009 – 2011 CNRS PhD Scholarship
2009 Ohm-Preis 2008/2009 of the Physics department at the University of Erlangen-Nuremberg, Germany
