Aktuelle Publikationen

September 2025

Resilience Enhancement of Optical Network-Cloud Ecosystems with Dataspace Framework and Multi-entity Cooperation (Invited)

Sugang Xu, Ronald Freund, Johannes Fischer, Mohammad Behnam Shariati, Pooyan Safari, Angela Mitrovska, Hideaki Furukawa, Subhadeep Sahoo, Yusuke Hirota, Yuki Yoshida, Kouichi Akahane, Sifat Ferdousi, Massimo Tornatore, Yoshinari Awaji , Biswanath Mukherjee

To enhance the resilience of network-cloud ecosystems, we establish a data governance framework for sharing optical testbed data across organizations and fostering machine learning research of optical networks. We further introduce multientity...


September 2025

Hybrid Photonic Integrated Circuit for Tunable, Narrow-Linewidth mmWave to sub-THz Signal Generation

Tianwen Qian

We experimentally demonstrate a photonic integrated circuit (PIC) that generates tunable mmWave signals with Hz-level linewidths. Utilizing on-chip optical frequency combs and injection locking, the phase-locked optical signals exhibit beat notes...


August 2025

On the effectiveness of multimodal privileged knowledge distillation in two vision transformer based diagnostic applications

Simon Baur, Jackie Ma, Emilio Dolgener Cantú, Alexandra Benova

Deploying deep learning models in clinical practice often requires leveraging multiple data modalities, such as images, text, and structured data, to achieve robust and trustworthy decisions. However, not all modalities are always available at...


August 2025

Quantification of Degradation Processes in Lithium-Ion Batteries Through Internal Strain Measurement with Fiber Bragg Grating Sensors

Leonard Kropkowski, Wolfgang Schade, Antonio Nedjalkov, Tim Oestreich, Fangqi Li, Alexandra Burger, Andreas Würsig

This study explores the use of fiber optical sensors with Bragg gratings to monitor internal strain in lithium-ion battery anodes, offering new insights into aging and degradation. By combining optical measurements with traditional methods, it...


August 2025

Deep Learning-Based Postprocessing to Enhance Subseasonal Soil Moisture Forecasts Over Europe

Noelia Otero Felipe, Jackie Ma, Atahan Özer

Accurate forecasts on subseasonal (S2S) timescales are essential for the preparation andmitigation of the impacts of high?impact events, such as flash droughts. To improve the accuracy of soilmoisture forecasts—a critical factor in identifying...


August 2025

Spatially Resolved Rainfall Streamflow Modeling in Central Europe

Marc Vischer, Jackie Ma, Noelia Otero Felipe

Climate change increases the risk of disastrous floods and makes intelligent fresh water management an ever more important issue for society. A central prerequisite is the ability to accurately predict the water level in rivers from a range of...


August 2025

On Level Crossings and Fade Durations in von Mises-Fisher Scattering Channels

Kenan Turbic, Slawomir Stanczak, Martin Kasparick

The paper presents closed-form analytical expressions for the level-crossing rate (LCR) and average fade duration (AFD) in channels with von Mises–Fisher (vMF) scattering. This work complements our previous results on correlation functions and...


August 2025

An Open Source Digital Twin Framework for O-RAN

Hammad Zafar, Slawomir Stanczak, Martin Kasparick, Ehsan Tohidi

This paper introduces a digital twin framework for O-RAN, designed to support the development and testing of xApps. By leveraging real-time data analysis and simulation, digital twins facilitate network performance optimization and enable a...


August 2025

Reconfigurable Intelligent Surface Placement for Enhanced User Equipment Coverage

Sven Haesloop, Slawomir Stanczak, Ehsan Tohidi

This work investigates how smart placement of Reconfigurable Intelligent Surfaces (RISs) can extend wireless coverage by considering Line-of-Sight conditions and surface orientation as key design factors. A low-complexity algorithm enables...


August 2025

Sub-THz Waveguide Band-Pass Filter: Design, Analysis and Fabrication Repeatability

Mehmet Ahad Yurtoglu, Michael Peter, Ramez Askar, Sven Wittig

This work presents high-precision all-metal Chebyshev band-pass filters operating in the Y-band (470?GHz) and D-band (160?GHz), featuring six coupled cavities and 10?GHz bandwidth with 20?dB return loss. CNC milling enables sub-5??m fabrication...


August 2025

Geometrical and Physical Optics Analysis of Sub-THz Elliptical Dielectric Lens

Vitor Carvalho De Almeida, Wilhelm Keusgen, Michael Peter, Ramez Askar

Analysis of dielectric lens in sub-THz frequencies often demands huge computational effort for full-wave electromagnetic methods. This paper presents an asymptotic technique for lens analysis at D-band, using ray tracing and applying Kirchhoff’s...


August 2025

E2E energy monitoring for AI inference in mobile networks

Abhishek Girish Dandekar, Julius Schulz-Zander, Ashrafur Rahman

When doing edge inference, VLM models in certain situations might consume similar energy as that of private 5G networks.


Juli 2025

Demonstration of a Programmable Node Prototype for Spatial Lane Switching and Band Switching

Abdelrahmane Moawad, R. Morro, Colja Schubert, Robert Emmerich, Johannes K. Fischer, Mohammad Behnam Shariati, A. Giorgetti, Caio Marciano Santos, Hussein Zaid

In this work, we designed a passive 2×2 MBoSDM node prototype that is capable of band and space/fiber switching. The prototype is fully controllable though an SDN agent and supports selective band switching as well as add/drop functions for the...


Juni 2025

Interoperable and Open Source Solution for Anchoring Augmented Reality Content to the Real World

Sylvain Buche, Ingo Feldmann, Sylvain Renault, Jérome Royan, Patrick Harns, Hugo Kreber, Jeremy Lacoche, Stephane Louis Dit Picard

This research demonstration presents an open source end-to-end solution for facilitating the anchoring of virtual content in the real world based on various platforms thanks to the interoperable specifications of the ETSI Augmented Reality...


Juni 2025

A Fast and Accurate EDFA Model for the Optimization of Power-Efficient SDM Subsea Transmission Systems

Aymeric Arnould, Ronald Freund, Georg Rademacher

In this paper, we present an adaptation of the extended Saleh model, using a coarse segmentation of the erbium doped fiber, to accurately include the impact of EDFA physics, with a limited complexity increase, in power efficiency predictions for...


Juni 2025

Beam-Steered Sub-THz Channel Measurements in D-Band in an Industrial Environment

Alper Schultze, Wilhelm Keusgen, Michael Peter, Ramez Askar, Taro Eichler, Mathis Schmieder

This paper presents results of a channel measurement campaign carried out in a production hall at a carrier frequency of 160 GHz which were analyzed with regards to beam-steering and macro-diversity gains.


Juni 2025

On the Impact of OFDM Waveform in ISAC Systems

Abdolvakil Fazli, Slawomir Stanczak, Zoran Utkovski, Patrick Agostini, Ehsan Tohidi

This paper highlights the differences between the standard matched filter (a correlation-based method) and symbol-domain processing, providing insights into how pulse shaping affects sensing performance in multicarrier schemes like OFDM....


Juni 2025

Conflict Mitigation Approach for O-RAN xApps

Hammad Zafar, Slawomir Stanczak, Martin Kasparick, Ehsan Tohidi

Open Radio Access Network (O-RAN) enables interoperability by allowing operators to choose equipment from multiple vendors. However, conflicting objectives between xApps, such as energy efficiency and load balancing, require coordination, raising...


Juni 2025

Angle-Resolved Channel Measurements at 28 and 160 GHz in Open Office Industrial-Like Environment

Mathis Schmieder, Wilhelm Keusgen, Michael Peter, Ramez Askar, Alper Schultze, Niclas Woodstock Kullig

This paper investigates angle-resolved channel measurements at 28 and 160 GHz within an industrial-like open office environment. It presents findings on power metrics, delay, and angular characteristics based on 135 measurement positions. Results...


Juni 2025

N-Heterocyclic Olefins of Pyrazole and Indazole

Bloin Zhu, Eike Hübner, Felix Lederle, Andreas Schmidt, Rouven Woyciechowski

Deprotonation of 3-methylpyrazolium and 3-methylindazolium salts yielded N-heterocyclic olefins (NHOs), which reacted with isocyanates, halogens, and carbon disulfide. Calculated proton affinities are 261 kcal/mol (indazole NHOs) and 272 kcal/mol...


Juni 2025

Datasets for QoT estimation in SDM networks

Hassan Akbari, R. Freund, Johannes K. Fischer, Mohammad Behnam Shariati, Pooyan Safari, Juan L. Morrone

The advancement of machine learning (ML)-assisted solutions for monitoring and performance analysis in space-division multiplexing (SDM) networks has been significantly constrained by a shortage of large, well-structured, and publicly available...


Juni 2025

High-Capacity THz Wireless Transmission Supporting Future 6G Optical Networks

Colja Schubert, Martin Schell, Ronald Freund, Robert Elschner, Simon Nellen, Robert Kohlhaas, Oliver Stiewe, Milan Deumer, Thomas Merkle, Axel Tessmann, In-Ho Baek, Frederik Bart, Fred Meier, Andreas Maaßen, Kallyan Das, Simon Schütze, Markus Rösch

The paper reviews recent developments in high-capacity THz wireless transmission, focusing on point-to-point links in the lower THz frequency range around 300 GHz. Available technologies and challenges for integration into future 6G optical...


Juni 2025

140 GBd S-C-L-Band Transmission System Enabled by TFLN Coherent Driver Modulator and InP Coherent Receiver Engine

Robert Emmerich, Patrick Runge, Martin Schell, Colja Schubert, Ronald Freund, Alexander Schindler

We demonstrate high symbol rate (128/140-Gbaud QPSK/16QAM) transmission for multi-band systems (S-C-L-band) with commercially available components. The broadband thin film lithium niobate high-bandwidth modulator and the HHI designed InP coherent...


Mai 2025

Inter-hospital transferability of AI: A case study on phase recognition in cholecystectomy

Lasse Renz-Kiefel, Peter Eisert, Anna Hilsmann, Eric Wisotzky, sebastian Lünse, Rene Mantke

Identifying surgical phases is a crucial component of surgical workflow analysis, facilitating the automated evaluation of surgical procedures’ performance and efficiency. A significant challenge in developing neural networks for surgical phase...


Mai 2025

Monolithic InP Ring Resonator based Laser with 40 kHz Linewidth and 40 nm Tuning Range

Hendrik Boerma, Patrick Runge, Martin Schell, Arbnor Berisha, Daniel Haubenreißer

A narrow linewidth tunable laser based on ring resonators is presented. It uses low loss passive waveguides implemented in a monolithic InP photonic integrated circuit. The laser can be tuned over a wavelength range from 1559 nm to 1602 nm. The...


Mai 2025

Clock offset synchronization with sublinear complexity for quantum key distribution on low-level hardware

Jan Krause, Ronald Freund, Jonas Hilt, Nino Walenta

We introduce iQSync, a clock-offset recovery method for quantum key distribution. iQSync achieves sub-linear computational complexity, allowing for the implementation on low-level hardware. We demonstrate the method for channel attenuations...


Mai 2025

Single-Carrier 2.56 Tb/s (3-mode x 128-GBd x DP-16QAM) Transmission over a 53.7 km Few Mode Fiber

Nicolas Braig-Christophersen, Colja Schubert, Carsten Schmidt-Langhorst, Ronald Freund, Robert Emmerich, Fabian Chowanek, Georg Rademacher, Hideaki Furukawa, Aymeric Arnould, Benjamin J. Puttnam, Kazuhiko Aikawa, Juan Carlos Alvarado Zacarias, Rodrigo Amezuca-Correa, Ruby S. B. Ospina

We investigate high-symbol rate SDM transmission using 16 to 128 GBd QPSK, 16-QAM and 64-QAM modulation over a 3-mode fiber. An aggregated net rate of 2.56 Tb/s was obtained after 54 km transmission using 128 GBd 16-QAM signals.


Mai 2025

A Flexible Real-Time Quantum Key Distribution System for Fiber and Free-Space Links

Jan Krause, Ronald Freund, Jonas Hilt, Nino Walenta

To enable QKD in various scenarios, we developed a 625 MHz real-time autonomous timebin-phase QKD system with custom clock synchronization. We demonstrate the system’s performance and robustness under unstable link conditions, a variety of fiber...


Mai 2025

Realtime-Rendering of Dynamic Scenes with Neural Radiance Fields

Kilian Leonard Krause, Peter Eisert, Anna Hilsmann, Wieland Morgenstern

This paper addresses the challenge of real-time rendering of dynamic 3D scenes using Instant Neural Graphics Primitives (iNGP), training a separate radiance field for each frame. To enable interactive VR playback, efficient data storage and...


Mai 2025

Timebin-Phase BB84 Quantum Key Distribution Using Telecom-Wavelength Fiber-Coupled SPADs

Jan Krause, Patrick Runge, Martin Schell, Ronald Freund, Nino Walenta, Pascal Rustige

Single-photon avalanche detectors (SPADs), which operate without cryogenic cooling, are a core component for practical QKD systems. We demonstrate 13-hour continuous key generation with our timebin-phase BB84 QKD system using our InGaAs/InP SPAD,...


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