Vahid Ansari

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We report on the implementation of a time-multiplexed click detection scheme to probe quantum correlations between different spatial optical modes. We demonstrate that such measurement setups can uncover nonclassical correlations in multimode light fields even if the single mode reductions are purely classical. The nonclassical character of correlated(More)
We implement an ultrafast pulsed type-II parametric down conversion source in a periodically poled KTP waveguide at telecommunication wavelengths with almost identical properties between signal and idler. As such, our source resembles closely a pure, genuine single mode photon pair source with indistinguishable modes. We measure the joint spectral intensity(More)
Hybrid quantum networks rely on efficient interfacing of dissimilar quantum nodes, as elements based on parametric downconversion sources, quantum dots, colour centres or atoms are fundamentally different in their frequencies and bandwidths. Although pulse manipulation has been demonstrated in very different systems, to date no interface exists that(More)
Vahid Ansari, ∗ Markus Allgaier, Linda Sansoni, Benjamin Brecht, 2 Jonathan Roslund, Nicolas Treps, Georg Harder, and Christine Silberhorn Integrated Quantum Optics, Paderborn University, Warburger Strasse 100, 33098 Paderborn, Germany Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU, United Kingdom Laboratoire Kastler(More)
J. Tiedau, V. S. Shchesnovich, D. Mogilevtsev, V. Ansari, G. Harder, T. Bartley, N. Korolkova and Ch. Silberhorn Applied Physics, University of Paderborn, Warburgerstrasse 100, 33098 Paderborn, Germany; Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Santo Andre, SP, 09210-170 Brazil; Institute of Physics, Belarus National Academy of(More)
In the last few decades, there has been much progress on low loss waveguides, very efficient photon-number detectors and nonlinear processes. Engineered sum-frequency conversion is now at a stage where it allows operation on arbitrary temporal broadband modes, thus making the spectral degree of freedom accessible for information coding. Hereby the(More)
Encoding quantum information in the photon temporal mode (TM) offers a robust platform for high-dimensional quantum protocols. The main practical challenge, however, is to design a device that operates on single photons in specific TMs and all coherent superpositions. The quantum pulse gate (QPG) is a mode selective sum-frequency generation designed for(More)
Encoding information in temporal modes (TMs) is an intriguing scheme in quantum information science. The main practical challenge, however, is to design a device that operates on phase and amplitude of TMs carried by quantum states. The quantum pulse gate (QPG) is a mode selective sum-frequency generation designed for this task. Here, we perform a full(More)
Markus Allgaier, ∗ Vahid Ansari, Christof Eigner, Viktor Quiring, Raimund Ricken, John Matthew Donohue, Thomas Czerniuk, Marc Aßmann, Manfred Bayer, Benjamin Brecht, 3 and Christine Silberhorn Integrated Quantum Optics, Applied Physics, University of Paderborn, 33098 Paderborn, Germany Experimentelle Physik II, Technische Universität Dortmund, D-44221(More)
The spectral-temporal correlation and the correlation time of a biphoton wavepacket generated in the process of parametric down-conversion (PDC), is of great importance for a broad range of quantum experiments. We utilise an integrated PDC source to generate biphotons with different types of spectral-temporal correlations and probe their respective(More)
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