Publications

47 Publikationen filtern

Die Publikationen filtern

Highlighted authors are members of the University of Jena.

  1. Ultra-compact payload for a LEO-orbit based entanglement QKD mission using cubesats

    Year of publicationPublished in:Quantum Computing, Communication, and Simulation V E. Beckert, D. Heinig, F. Steinlechner, K. Fuechsel, M. Beier, K. Schilling, A. Kloth
    University Bibliography Jena:
    fsu_mods_00024480External link

  2. A predictive polarisation compensation method for dynamic free-space optical links in quantum communication

    Year of publication T. Parab
    Quantum communication, particularly quantum key distribution (QKD), leverages the principles of quantum mechanics to provide secure information exchange. A key challenge in airborne quantum communication setups is the preservation of polarisation states during photon transmission between a moving aircraft and a ground station. In this work, I propose a polarisation compensation model designed to mitigate the distortions introduced by dynamic optical elements, including the aircraft’s coarse pointing assembly (CPA), the periscope system of the ground station (QuBus), and other optical components. These distortions can degrade the performance of both QKD and any interfacing experiments requiring coupling of these transmitted photons. By characterising the polarisation transformations introduced by these elements, I develop a polarisation correction mechanism based on a three-waveplate configuration consisting of two quarter-wave plates (QWPs) and one half-wave plate (HWP). This dynamic compensation system adjusts in real-time, based on positional data from the QuBus periscope. Laboratory tests have demonstrated the feasibility of this correction mechanism in terms of speed, achieving adjustments within 2.54 seconds, thus allowing for compensation on aircraft with a traverse angle rate of change of up to 0.413°/sec. The effectiveness of this system will be further evaluated in the upcoming 935 nm interfacing experiment, scheduled for March 2025, providing critical insights into its real-world applicability and its potential to enhance the reliability of free-space quantum communication systems.
    University Bibliography Jena:
    fsu_mods_00027455External link

  3. Plug-and-play solution for characterizing two-way optical frequency transfer over free-space

    Year of publicationStatusReview pendingPublished in:Optics Express J. Ji, S. Mukherjee, A. Kuhl, S. Koke, M. Leipe, M. Rothe, F. Steinlechner, J. Kronjäger
    Optical clock networks connected by phase-coherent links offer significant potential for advancing fundamental research and diverse scientific applications. Free-space optical frequency transfer extends fiber-based connectivity to remote areas and holds the potential for global coverage via satellite links. Here we present a compact and robust portable, rack-integrated two-way free-space link characterization system. Equipped with plug-and-play capabilities, the system enables straightforward interfacing with various optical systems and facilitates quick deployment for field experiments. In this work, we achieve a fractional frequency instability of 2.0 × 10−¹⁹ for an averaging time of 10 s over a 3.4 km horizontal fully folded intra-city free-space link. Moreover, the system maintains an uptime of 94% over 15 hours, illustrating its reliability and effectiveness for high-precision optical frequency comparisons over free-space.
    University Bibliography Jena:
    fsu_mods_00027552External link

  4. Time-Resolved Measurement of Hong-Ou-Mandel Interference from integrated SPDC sources

    Year of publicationStatusReview pendingPublished in:2025 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2025 K. Lozano-Mendez, M. Cabrejo-Ponce, B. Baghdasaryan, F. Steinlechner
    University Bibliography Jena:
    fsu_mods_00027651External link

  5. Clock synchronization with pulsed single photon sources

    Year of publicationPublished in:Quantum Science and Technology C. Spiess, F. Steinlechner
    Photonic quantum technology requires precise, time-resolved identification of photodetection events. In distributed quantum networks with spatially separated and drifting time references, achieving high precision is particularly challenging. Here we build on recent advances of using single-photons for time transfer and employ and quantify a fast postprocessing scheme designed to pulsed single-photon sources. We achieve an average root mean square synchronization jitter of 3.0 ps. The stability is comparable to systems with Rb vapor cell clocks with 19 ps at 1 s integration time, in terms of Allan time deviation. Remarkably, our stability is even better than classical high-precision time transfer, like the White Rabbit protocol, although we use significantly less signal (single-photon level). Our algorithms allow local processing of the data and do not affect the secure key rate. It compensates substantial clock imperfections from crystal oscillators and we foresee great potential for low signal scenarios. The findings are naturally suited to quantum communication networks and provide simultaneous time transfer without adding hardware or modifying the single-photon sources.
    University Bibliography Jena:
    fsu_mods_00009581External link

  7. Spatiotemporal Description of Non-linear Interference Based on Cascaded Spontaneous Parametric Down-Conversion.

    Year of publicationPublished in:Proceedings : Quantum 2.0 Conference and Exhibition : 23–27 June 2024, Rotterdam, Netherlands C. Sevilla-Gutiérrez, P. Chauhan, F. Steinlechner
    University Bibliography Jena:
    fsu_mods_00018757External link

  8. Enhancing Quantum Communications: Automated, Ultra-Bright Entangled Photon Generation

    Year of publicationPublished in:Proceedings : Quantum 2.0 Conference and Exhibition : 23–27 June 2024, Rotterdam, Netherlands R. Sebak, R. Gomez, S. Gamarra, J. Tafur, E. Beckert, F. Steinlechner
    University Bibliography Jena:
    fsu_mods_00018764External link

  9. Design and Manufacturing of a metallic telescope for ground-based Quantum communication

    Year of publicationPublished in:Optical Fabrication and Testing VIII M. Unger, N. Heidler, T. Peschel, C. Damm, R. Jende, P. Weide, K. Kleinbauer, R. Steinkopf, T. Porwol, S. Müller, M. Rohde, J. Hartung, C. Jäger, S. Shestaeva, R. Schlegel, S. Schwinde, M. Goy, F. Steinlechner, S. Risse
    University Bibliography Jena:
    fsu_mods_00016181External link

  10. Ultra-bright polarization entangled photon sources, e.g. based on time-reversed Hong-Ou-Mandel interference

    Year of publicationPublished in:Quantum Computing, Communication, and Simulation IV: 27 January-1 February 2024, San Francisco, California, United States E. Beckert, R. Sebak, F. Steinlechner, R. Gomez, C. Luna, S. Sharma, E. Brambila-Tamayo, C. Melo Luna
    University Bibliography Jena:
    fsu_mods_00018419External link

  11. Continuous Polarization Correction for Long-distance Quantum Key Distribution

    Year of publicationPublished in:Proceedings : Quantum 2.0 Conference and Exhibition : 23–27 June 2024, Rotterdam, Netherlands U. Chandrashekara, A. Kržič, R. Gómez, F. Steinlechner
    University Bibliography Jena:
    fsu_mods_00018760External link

  12. Engineering Spectral Purity of Telecom Wavelength Photons Generated via SPDC for Multi-partite Quantum Communication

    Year of publicationPublished in:Proceedings : Quantum 2.0 Conference and Exhibition : 23–27 June 2024, Rotterdam, Netherlands J. Conrad, R. Gómez, M. Leipe, M. Ponce, F. Steinlechner
    University Bibliography Jena:
    fsu_mods_00018767External link
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