Experimental Quantum Information
Prof. Dr. Fabian STEINLECHNER
Prof. Fabian Steinlechner
Image: Ira Winkler
Prof. Fabian Steinlechner.
Image: Fraunhofer IOFProf. Dr. Fabian STEINLECHNER
Email: fabian.steinlechner@uni-jena.de
Phone: +49 3641 807 733
Carl-Zeiss-Stiftung Logo
Picture: Carl-Zeiss-Stiftung.Support by the CZS Center Photon
Prof. Fabian Steinlechner received his PhD in 2015 from ICFO in Barcelona, where his doctoral research focused on quantum light sources for space applications. As a postdoctoral researcher at the Institute for Quantum Optics and Quantum Information in Vienna, he worked on entangled photons for fundamental tests of quantum mechanics, quantum sensing, high-dimensional quantum information and long-distance quantum communication.
In 2018, he established the “Quantum Communication Technologies” group at Fraunhofer IOF in Jena. Since 2023, he has been Professor of Experimental Quantum Information at the Institute of Applied Physics of Friedrich Schiller University Jena. His professorship is supported by the Carl-Zeiss-Stiftung within the CZS Center for Quantum Photonics (QPhoton)External link.
The Steinlechner group conducts experimental and application-oriented research in quantum communication and photonic quantum information processing. Its work spans the development of quantum light sources, high-dimensional and distributed quantum information protocols, photonic quantum processing, and robust hardware for fiber, free-space and satellite-based quantum networks.
Dr. Fabian Steinlechner received his PhD in 2015 from ICFO (Barcelona, Spain) where his doctoral research focused on the development of quantum light sources for applications in Space. As a postdoctoral fellow at the Institute for Quantum Optics and Quantum Information in Vienna, he contributed to the application of entangled photons in loophole-free tests of non-locality, quantum sensing, high-dimensional quantum information processing, and long-distance quantum communication in free-space and fiber links. In 2018, he established the “Quantum Communication Technology” group at Fraunhofer IOF via the Attract program. Since 2020 he is acting as group leader of the “Active and Adaptive Optics” group at IOF and the “Photonic Quantum Information” group at the Institute of Applied Physics, where he received a call to become full professor in 2023. The professorship is supported by the Carl-Zeiss-StiftungExternal link within its Carl-Zeiss-Stiftung Center for Quantum Photonics (CZS Center QPhoton)
The Steinlechner group conducts applied research in the field of quantum communication and photonic quantum information processing. Working in close collaboration with partners in academia and industry we aim to bridge the gap between fundamental quantum research and real-world applications. Our research focuses on novel quantum light sources for applications in quantum communication and sensing, efficient processing and detection schemes for high-dimensional quantum information, as well as scalable methods for the transmission of quantum states over long distances. A central goal is to incorporate photonic quantum technology in robust, field-deployable hardware systems that are suitable for integration in future quantum networks, long-distance atmospheric free-space links, and ultimately satellite-based quantum key distribution sytems.
Research Areas
Entangled and non-classical states of light provide key resources for quantum communication, sensing and photonic quantum information processing. Prof. Steinlechner's research focuses on the generation, manipulation, transmission and detection of complex photonic quantum states, with particular emphasis on scalable and field-deployable quantum technologies. Research topics include:
- Entangled and engineered quantum light sources based on nonlinear optics
- High-dimensional quantum information processing in spatial, temporal and spectral degrees of freedom
- Hyperentanglement and multiplexed photonic quantum information
- Quantum communication and distributed quantum networks
- Free-space, fiber-based and satellite quantum communication
- Photonic quantum processing and multi-photon interference
- Non-classical light for quantum sensing, ranging and remote sensing
Teaching Fields
- Fundamentals of quantum information
- Quantum communication
- Experimental photonic quantum technologies
Research Methods
The group utilizes modern experimental equipment including:
- Entangled and heralded quantum light sources based on nonlinear parametric processes
- Pulsed and cw lasers from the visible to telecom wavelengths
- Time-resolved single-photon detection and time-tagging electronics
- High-speed electro-optic modulation and pulse shaping
- Wavelength-division multiplexing and spectral-mode manipulation
- Spatial light modulation, adaptive optics and multi-mode photonic processing
- Free-space quantum communication terminals and deployed fiber links
- Quantum key distribution and quantum-network testbeds
- Integrated and bulk-optical platforms for photonic quantum information processing
(left) Schematic representation of multi-plane light conversion for efficient manipulation and analysis of high-dimensional quantum states. (right) Spatial correlations of entangled photon pairs generated via parametric down conversion in a LaguerreGauss detection basis.
Graphic: Steinlechner research group, published.Recent Research Results
Recent research focuses on translating photonic quantum information from laboratory experiments towards scalable quantum networks and field-deployable systems. The group has demonstrated entanglement-based quantum key distribution over metropolitan free-space links, including robust operation under daylight conditions, and contributes to hybrid quantum networks combining free-space and fiber-based transmission [1,2].
A second focus is the use of high-dimensional and multiplexed photonic states for quantum information processing and communication. Recent experiments include the transport and analysis of high-dimensional spatial information as well as frequency-subspace encoding for multiplexed quantum secret sharing [3,4].
The group develops compact and efficient entangled-photon sources at visible, near-infrared and telecom wavelengths, with emphasis on high brightness, stability and suitability for deployment outside the laboratory [5]. Current work further addresses multi-photon interference between independent quantum sources as a key building block for distributed quantum information processing and future quantum networks [6].
In parallel, the group develops technologies for long-distance and satellite quantum communication. This includes compact quantum payloads, adaptive free-space optical systems and experimental satellite missions. In 2025, the QUICK³ nanosatellite carrying technologies for space-based quantum communication was successfully launched into Earth orbit.
[1] Kržič et al., npj Quantum Inf. 9, 95 (2023).
[2] Goy et al., New J. Phys. 27, 114510 (2025).
[3] Sephton et al., Nat. Commun. 14, 8243 (2023).
[4] Cabrejo-Ponce et al., Optica Quantum 3, 552 (2025).
[5] Fazili et al., J. Opt. Soc. Am. B 41, 2692 (2024).
[6] Baghdasaryan et al., npj Quantum Inf. 12 (2026).