Aktuelle Publikationen

Januar 2021

InP-Components for 100 Gbaud Optical Data Center Communication

Patrick Runge, Martin Möhrle, Martin Schell, Ute Troppenz, Marko Gruner, Tobias Beckerwerth, Hendrik Boerma

Externally modulated DFB lasers (EML) and vertically illuminated photodetectors are presented. Because of their excellent high-speed behavior and operation wavelength of 1310 nm, the devices are of interest for intra-data center communication. Since the EML and the photodetector chips are compatible with current systems, these devices are candidates for upgrading existing transceivers to higher baud rates. Therefore, a proof of concept for 100 GBaud data transmission with the presented components is demonstrated. Even without predistor! tion, the experiments show clearly open eye diagrams.


Januar 2021

Robustifying Models Against Adversarial Attacks by Langevin Dynamics

Vignesh Srinivasan, Klaus-Robert Müller, Wojciech Samek, Shinichi Nakajima, Arturo Marban

This paper proposes a novel, simple yet effective defense strategy for adversarial attacks on deep learning models. Our algorithm, called MALA for DEfense (MALADE), is applicable to any existing classifier, providing robust defense as well as off-manifold sample detection. In our experiments, MALADE exhibited state-of-the-art performance against various elaborate attacking strategies.


Januar 2021

Inverse Design Strategies for Large Passive Waveguide Structures

Marko Perestjuk, Patrick Runge, Martin Schell, Alexander Schindler, Hendrik Boerma

Inverse design is rapidly gaining popularity for automated design of photonic components. Two methods to improve it for large passive waveguide structures are developed: Adaptive Threshold Binarization and Hybrid Optimization. To demonstrate their capability, inverse design is applied to an InP waveguide platform for the first time. As an example, a polarizer with a PER of -19.4 dB is presented.


Dezember 2020

Neural Face Models for Example-Based Visual Speech Synthesis

Wolfgang Paier, Peter Eisert, Anna Hilsmann

In this paper we present an example-based approach for visual speech synthesis. We combine the advantages of deep generative models and classical animation approaches to create a real-time capable facial animation framework based on volumetric captures.


Dezember 2020

Second Harmonic Generation in Polymer Photonic Integrated Circuits

Hauke Conradi, Norbert Keil, Martin Schell, Moritz Kleinert, Crispin Zawadzki, Ronald Freund, David de Felipe Mesquida, Martin Kresse, Björn Globisch, Lars Liebermeister, Almontaserbillah Hakmi, Madeleine Weigel

Second harmonic generation is an efficient way to create coherent radiation at wavelengths that are not accessible with standard laser sources. In this work we demonstrate second harmonic generation from 1550 nm to 775 nm in a polymer photonic integrated circuit via the hybrid integration of a periodically poled lithium niobate crystal. The bulk crystal is inserted in an on-chip free-space section between two waveguide couple! d GRIN lenses. Fiber to fiber conversion efficiencies were 0.03 %/W for a continuous wave laser source and 100 %/W for a femtosecond laser source. Furthermore, third and fourth harmonic light at 517 nm and 388 nm was observed.


Dezember 2020

Demonstration of Federated Learning over Edge-Computing Enabled Metro Optical Networks

Mohammad Behnam Shariati, Pooyan Safari, Angela Mitrovska, Nazila Hashemi, Johannes Fischer, Ronald Freund

We demonstrate the benefits of a federated learning framework for (re)training of global ML models over geo-distributed data sources. The demonstration is carried out on a live edge computing enabled optical networking test-bed. In this demonstration, we perform real-time training of a QoT classifier by exploiting data of three different Domain Managers (DM), representing a multi-vendor ecosystem, without sharing any data with the Network Management System (NMS) in order to avoid transporting any data t! o a central location and to protect the privacy of different vendors while offering their knowledge to train a global ML model.


Dezember 2020

Predictive Resource Allocation for Automotive Applications using Interference Calculus

Daniel Fabian Külzer, Slawomir Stanczak, Renato L. G. Cavalcante, Mladen Botsov

In autonomous driving, safety-related connected applications will coexist with infotainment services. We propose a multi-cell anticipatory networking framework with interference coordination based on Interference Calculus to serve diverse QoS requirements. The iterative approach optimizes packet transmission times leveraging service properties and channel distribution information.


November 2020

Experimental Demonstrations of High-Capacity THz-Wireless Transmission Systems for Beyond 5G

Carlos Moises Castro Posada, Robert Elschner, Thomas Merkle, Colja Schubert, Ronald Freund

Using the concept of a “THz-Wireless Fiber Extender” it is possible to combine the flexibility of wireless networks with the high capacity of fiber-optical networks. In this article, we report on a real-time short-range demonstration of a 100 Gb/s fiber extender and discuss the potential of long-range data transmission at 300 GHz using a 500-meter-long wireless link in Berlin, Germany.


November 2020

Dual-Band Node Architectures for C+L-Band Capacity Upgrades in Optical Metro Transport Networks

Robert Emmerich, António Eira, Nelson Costa, Pablo Wilke Berenguer, Robert Elschner, Colja Schubert, Johannes Fischer, João Pedro, Ronald Freund

To address the capacity crunch in optical metropolitan networks caused by the roll out of innovations in the context of 5G and beyond innovative approaches are required to increase the achievable throughput. Multi band systems are an interesting solution to address this issue. In this contribution, we investigate the capacity limits of such networks.


November 2020

Security Gap Investigation of Multilevel Coding in Coherent Fiber-Optical Systems

Johannes Pfeiffer, Carsten Schmidt-Langhorst, Robert Elschner, Felix Frey, Robert Emmerich, Colja Schubert, Robert F. H. Fischer

Using a coherent laboratory setup with up to 768 Gb/s data rate (64-GBd DP-64QAM), we experimentally show that multilevel coding (MLC) provides superior physical layer security (i.e. smaller security gaps) as compared to conventional bit-interleaved coded modulation (BICM) . MLC offers a flexible trade-off between security and net secure data rate.



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