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Subject: search.filters.subject.530Institute: search.filters.UBSInstitut.Stuttgart Research Centre of Photonic Engineering (SCoPE)Institute: search.filters.UBSInstitut.Fakultätsübergreifend / Sonstige EinrichtungPublication Type: search.filters.UBSTyp.ZeitschriftenartikelStart date: 2020End date: 2020

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Now showing 1 - 5 of 5
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    Tailored nanocomposites for 3D printed micro-optics
    (2020) Weber, Ksenia; Werdehausen, Daniel; König, Peter; Thiele, Simon; Schmid, Michael; Decker, Manuel; Oliveira, Peter William de; Herkommer, Alois; Giessen, Harald
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    Vibrational quenching of weakly bound cold molecular ions immersed in their parent gas
    (2020) Jachymski, Krzysztof; Meinert, Florian
    Hybrid ion–atom systems provide an excellent platform for studies of state-resolved quantum chemistry at low temperatures, where quantum effects may be prevalent. Here we study theoretically the process of vibrational relaxation of an initially weakly bound molecular ion due to collisions with the background gas atoms. We show that this inelastic process is governed by the universal long-range part of the interaction potential, which allows for using simplified model potentials applicable to multiple atomic species. The product distribution after the collision can be estimated by making use of the distorted wave Born approximation. We find that the inelastic collisions lead predominantly to small changes in the binding energy of the molecular ion.
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    Ultrathin monolithic 3D printed optical coherence tomography endoscopy for preclinical and clinical use
    (2020) Li, Jiawen; Thiele, Simon; Quirk, Bryden C.; Kirk, Rodney W.; Verjans, Johan W.; Akers, Emma; Bursill, Christina A.; Nicholls, Stephen J.; Herkommer, Alois; Giessen, Harald; McLaughlin, Robert A.
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    Electron-driven photon sources for correlative electron-photon spectroscopy with electron microscopes
    (2020) Christopher, Joshua; Taleb, Masoud; Maity, Achyut; Hentschel, Mario; Giessen, Harald; Talebi, Nahid
    Electron beams in electron microscopes are efficient probes of optical near-fields, thanks to spectroscopy tools like electron energy-loss spectroscopy and cathodoluminescence spectroscopy. Nowadays, we can acquire multitudes of information about nanophotonic systems by applying space-resolved diffraction and time-resolved spectroscopy techniques. In addition, moving electrons interacting with metallic materials and optical gratings appear as coherent sources of radiation. A swift electron traversing metallic nanostructures induces polarization density waves in the form of electronic collective excitations, i.e., the so-called plasmon polariton. Propagating plasmon polariton waves normally do not contribute to the radiation; nevertheless, they diffract from natural and engineered defects and cause radiation. Additionally, electrons can emit coherent light waves due to transition radiation, diffraction radiation, and Smith-Purcell radiation. Some of the mechanisms of radiation from electron beams have so far been employed for designing tunable radiation sources, particularly in those energy ranges not easily accessible by the state-of-the-art laser technology, such as the THz regime. Here, we review various approaches for the design of coherent electron-driven photon sources. In particular, we introduce the theory and nanofabrication techniques and discuss the possibilities for designing and realizing electron-driven photon sources for on-demand radiation beam shaping in an ultrabroadband spectral range to be able to realize ultrafast few-photon sources. We also discuss our recent attempts for generating structured light from precisely fabricated nanostructures. Our outlook for the realization of a correlative electron-photon microscope/spectroscope, which utilizes the above-mentioned radiation sources, is also described.
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    Extending quantum links : modules for fiber‐ and memory‐based quantum repeaters
    (2020) Loock, Peter van; Alt, Wolfgang; Becher, Christoph; Benson, Oliver; Boche, Holger; Deppe, Christian; Eschner, Jürgen; Höfling, Sven; Meschede, Dieter; Michler, Peter; Schmidt, Frank; Weinfurter, Harald
    Elementary building blocks for quantum repeaters based on fiber channels and memory stations are analyzed. Implementations are considered for three different physical platforms, for which suitable components are available: quantum dots, trapped atoms and ions, and color centers in diamond. The performances of basic quantum repeater links for these platforms are evaluated and compared, both for present‐day, state‐of‐the‐art experimental parameters as well as for parameters that can in principle be reached in the future. The ultimate goal is to experimentally explore regimes at intermediate distances - up to a few 100 km - in which the repeater‐assisted secret key transmission rates exceed the maximal rate achievable via direct transmission. Two different protocols are considered, one of which is better adapted to the higher source clock rate and lower memory coherence time of the quantum dot platform, while the other circumvents the need of writing photonic quantum states into the memories in a heralded, nondestructive fashion. The elementary building blocks and protocols can be connected in a modular form to construct a quantum repeater system that is potentially scalable to large distances.