Recent publications

November 2021

Linearity Characteristics of Avalanche Photodiodes For InP Based PICs

Tobias Beckerwerth, Patrick Runge, Martin Schell, Felix Ganzer, Robert Behrends

We demonstrate InP based PICs with MMIs and waveguide integrated avalanche photodiodes (APD). We investigate these devices regarding their DC and RF linearity characteristics and find a high bandwidth beyond 20 GHz and a dynamic range of 30 dB...


November 2021

On the Link between Subjective Score Prediction and Disagreement of Video Quality Metrics

Lohic Fotio Tiotsop, Sebastian Bosse, Florence Agboma, Glenn van Wallendael, Ahmed Aldahdooh, Lucjan Janowski, Marcus Barkowsky, Enrico Masala

 

It is common to observe signi?cant disagreements amongst the quality predictions of these VQMs for the same video sequence. Herein, a measure for quantifying the disagreement between VQMs is proposed. We propose a disagreement measure that...


November 2021

Demonstration of latency-aware 5G network slicing on optical metro networks

Mohammad Behnam Shariati, Ronald Freund, Johannes Fischer, R. Nejabati, Jörg-Peter Elbers, Dimitra Simeonidou, R. Casellas, O. González de Dios, A. Autenrieth, Luis Velasco, Ralf-Peter Braun, Annika Dochhan, Bodo Lent, Marc Ruiz, J.J. Pedreno-Manresa, A. S. Muqaddas, J. E. Lopez de Vergara, S. López-Buedo, F.J. Moreno, P. Pavón, S. Patri, A. Giorgetti, A. Sgambelluri, F. Cugini, L. Luque Canto

The H2020 METRO-HAUL European project has architected a latency-aware, cost-effective, agile, and programmable optical metro network. This includes the design of semidisaggregated metro nodes with compute and storage capabilities, which interface...


November 2021

Secure Multi-Party Computation and Statistics Sharing for ML Model Training in Multi-domain Multi-vendor Networks

Pooyan Safari, Johanna Fischer, Mohammad Behnam Shariati, Geronimo Bergk

We propose a secure aggregation algorithm that allows proprietary-owned domains, hosting statistically different datasets, train and operate ML models in a Horizontally Federated Learning fashion. The obtained results show a compelling test...


November 2021

Vertical Federated Learning for Privacy-Preserving ML Model Development in Partially Disaggregated Networks

Nazila Hashemi, Johannes Fischer, Mohammad Behnam Shariati, Pooyan Safari

We present a novel framework that enables vendors and operators, with partial access to operational and monitoring features of a service, to collaboratively develop a ML-assisted solution without revealing any business-critical raw data to each...


November 2021

Radiation pattern of planar optoelectronic antennas for broadband continuous-wave terahertz emission

Simon Nellen, Martin Schell, Björn Globisch, Robert Kohlhaas, Lars Liebermeister, Milan Deumer, Sebastian Lauck, Garrit William Johannes Schwanke

In future wireless communication networks at terahertz frequencies, the directivity and the beam profile of the emitters are highly relevant since no additional beam forming optics can be placed in free-space between the emitter and receiver. We...


November 2021

Can You Do Real-Time Gesture Recognition with 5 Watts?

Azrin Rahman, Peter Eisert, Sebastian Bosse, Detlef Runde, David Przewozny, Paul Chojecki, Mykyta Kovalenko

Accurate and reliable gesture recognition is a central problem in human-computer interaction (HCI). Many applications that make use of gesture recognition call for mobile devices with reduced power consumption, weight and form factors. Recent...


November 2021

Production environment of tomorrow (ProMo): Partially automated repair process of small tool moulds, forming tools, injection moulding tools and sand casting tools

Jan Kuschan, David Przewozny, Paul Chojecki, Vinzenz Müller, Stephan Mönchinger, Oliver Heimann, Carsten Niebuhr, Oday Kabha, Jörg Krüger

Small defects in the grain or major damage to a moulded part or tool can bring production to a standstill. SMEs in particular have neither the personnel nor the equipment to repair such damage on their own, so they send it to specialised...


October 2021

Endoscopic measurement of nasal septum perforations

Jean-Claude Rosenthal, Peter Eisert, Anna Hilsmann, Eric Wisotzky, Florian C. Uecker, Carsten Matuschek, Melanie Hobl

Nasal septum perforations (NSP) have many uncomfortable symptoms for the patient and a highly negative impact on quality of life. NSPs are closed using patient-specific implants or surgery. Implants are created either under anesthesia using...


October 2021

Enabling S-C-L-Band Systems with Standard C-Band Modulator and Coherent Receiver using Coherent System Identification and Nonlinear Predistortion

Robert Emmerich, Colja Schubert, Carsten Schmidt-Langhorst, Ronald Freund, Robert Elschner, Isaac Sackey, Matheus Ribeiro Sena

A promising solution to keep up with the rapid growth in global traffic while at the same time addressing increasing network cost, is the efficient reuse of installed legacy optical fiber. Multiband systems are promising solutions to capitalize...


September 2021

Feature Focus: Towards Explainable and Transparent Deep Face Morphing Attack Detectors

Clemens Peter Seibold, Peter Eisert, Anna Hilsmann

In this paper, we present Feature Focus, a new transparent face morphing detector based on a modified VGG-A architecture and an additional feature shaping loss function, as well as Focused Layer-wise Relevance Propagation (FLRP), an extension of...


September 2021

Formation of Titanium Nitride, Titanium Carbide and Silicon Carbide Surfaces by High Power Femtosecond Laser Treatment

R. Fedorov, Wolfgang Schade, Karl Wöbbeking, Mingji Li, Eike Hübner, Felix Lederle, V. Olszok

Surface treatment with femtosecond laser pulses at high repetition rates in the presence of gaseous sources for nitrogen and carbon leads to the formation of stable coatings with nitrides and carbides. High power femtosecond laser setups fill the...


September 2021

COMPASS: localization in laparoscopic visceral surgery

Regine Hartwig, Jean-Claude Rosenthal, Dirk Wilhelm, Hubertus Feussner, Daniel Ostler, Maximilian Berlet, Kevin Yu

Tracking of surgical instruments is an essential step towards the modernization of the surgical workflow by a comprehensive surgical landscape guidance system (COMPASS). Real-time tracking of a laparoscopic camera used in minimally-invasive...


September 2021

2D Optical Phased Arrays for Laser Beam Steering Based on 3D Polymer Photonic Integrated Circuits

Adam Raptakis, Christos Kouloumentas, Moritz Kleinert, Hercules Avramopoulos, Norbert Keil, Panos Groumas, Lefteris Gounaridis, Christos Tsokos, Madeleine Weigel, Michalis Georgiopoulos, Elias Mylonas

A novel concept for the implementation of 2-dimensional (2D) optical phased arrays (OPAs) with end-fire waveguides as antenna elements (AEs) is proposed and its theoretical model and experimental proof is presented. The concept is based on the...


September 2021

Influence of losses on the Laser Voltage drop of the active section

Magnus Happach, Norbert Keil, Martin Schell, Moritz Kleinert, Walter Brinker, Crispin Zawadzki, Martin Moehrle, David de Felipe Mesquida, Martin Kresse, Gelani Irmscher, Werner Hofmann, Victor Nicolai Friedhoff

A model of a tunable distributed Bragg reflector (DBR) laser describing the effect of cavity losses on the gain voltage is presented. Theoretical and experimental results are in good agreement. Measurements show the gain voltage trace for Bragg...


September 2021

Influence of losses on the Laser Voltage drop of the active section

Magnus Happach, Norbert Keil, Martin Schell, Moritz Kleinert, Walter Brinker, Crispin Zawadzki, Martin Moehrle, David de Felipe Mesquida, Martin Kresse, Gelani Irmscher, Werner Hofmann, Victor Nicolai Friedhoff

A model of a tunable distributed Bragg reflector (DBR) laser describing the effect of cavity losses on the gain voltage is presented. Theoretical and experimental results are in good agreement. Measurements show the gain voltage trace for Bragg...


September 2021

Interconnection challenges on integrated terahertz photonic systems

Guillermo Carpintero, Norbert Keil, David DeFelipe, Björn Globisch, Lars Liebermeister, Muhsin Ali, Luis Enrique Garcia-Munoz, Sebastian Lauck, Michael Nagel, Alejandro Rivera-Lavado, Daniel Gallego, Dmitry Lyubchenko, Nikolaos Xenidis, Enrique Prados-Castro, Jose Maria Pindado-Buendia, Riccardo Rossetti

Current challenges for RF interconnects are presented, esp. for calibrated measures of the frequency response of components operating > 100 GHz. Photonics and electronics are combined to develop new paradigm in the millimetre and Terahertz...


September 2021

Curiously Effective Features For Image Quality Prediction

Sören Becker, Thomas Wiegand, Sebastian Bosse

We find feature extractors constructed from random noise to be sufficient to learn a linear regression model whose quality predictions reach high correlations with human visual quality ratings, on par with a model with learned features.


September 2021

EEG-Based Analysis of the Impact of Familiarity in the Perception of Deepfake Videos

Jan-Philipp Tauscher, Marcus Magnor, Sebastian Bosse, Susana Castillo

Using EEG, we classify perceptual differences of familiar and unfamiliar people versus their face-swapped counterparts. Our results show that it is possible to discriminate fake videos from genuine ones when at least one face-swapped actor is...


September 2021

An Efficient Multi-Link Channel Model for LiFi

Sreelal Maravanchery Mana, Volker Jungnickel, Jonas Hilt, Peter Hellwig, Sepideh Mohammadi Kouhini, Kerolos Gabra Kamel Gabra

The emergence of LiFi for indoor communications opens up new possibilities for wireless services in crowded multiuser scenarios. The deployment of LiFi in indoor scenarios is challenging due to the line-of-sight (LOS) blockage as well as...


August 2021

Zero on Shape: A Generic 2D-3D Instance Similarity Metric learned from Synthetic Data

Maciej Janik, Peter Eisert, Anna Hilsmann, Niklas Gard

We present a network architecture which compares RGB images and untextured 3D models by the similarity of the represented shape. Our system is optimised for Zero-Shot retrieval, meaning it can recognise shapes never shown in training


August 2021

Enabling S-C-L-Band Systems with Standard C-Band Modulator and Coherent Receiver using Nonlinear Predistortion

Robert Emmerich, Colja Schubert, Carsten Schmidt-Langhorst, Ronald Freund, Robert Elschner, Isaac Sackey, Matheus Ribeiro Sena

To counteract the forthcoming capacity crunch in optical networks by increasing the throughput over already existing fiber infrastructures, innovative approaches are required. Multiband systems are an interesting approach to address this issue....


August 2021

S-Band Transmission with Off-the-Shelf C-Band Components Enabled by Nonlinear Predistortion based on Coherent System Identification

Robert Emmerich, Colja Schubert, Carsten Schmidt-Langhorst, Ronald Freund, Robert Elschner, Isaac Sackey, Mustafa Sezer Erkilinc, Matheus Ribeiro Sena

Nonlinear Predistortion based on Coherent System Identification Text: In order to cope with the rapid traffic growth and as well reducing the cost-per-bit, reuse of the legacy optical fiber infrastructure is one of the main objectives for...


August 2021

Clustered Federated Learning: Model-Agnostic Distributed Multi-Task Optimization under Privacy Constraints

Felix Sattler, Klaus-Robert Müller, Wojciech Samek

Federated learning (FL) is the most widely adopted framework for collaborative training of deep learning models under privacy constraints. Albeit its popularity, it has been observed that FL yields suboptimal results if the clients’ data...


August 2021

FantastIC4: A Hardware-Software Co-Design Approach for Efficiently Running 4bit-Compact Multilayer Perceptrons

Simon Wiedemann, Thomas Wiegand, Wojciech Samek, Friedel Gerfers, Daniel Becking, Suhas Shivapakashy, Pablo Wiedemann

With the growing demand for deploying Deep Learning models to the “edge”, it is paramount to develop techniques that allow to execute models within very tight and limited resource constraints. In this work we propose a software-hardware...


August 2021

Explain and Improve: LRP-Inference Fine Tuning for Image Captioning Models

Jiamei Sun, Wojciech Samek, Alexander Binder, Sebastian Lapuschkin

This paper analyzes the predictions of image captioning models with attention mechanisms beyond visualizing the attention itself. We compare the interpretability of attention heatmaps systematically against the explanations. We demonstrate that...


August 2021

LiFi Positioning for Industry 4.0

Sepideh Mohammadi Kouhini, Volker Jungnickel, Ronald Freund, Christoph Kottke, Ziyan Ma, Marcel Müller, Daniel Behnke, Marcos Martinez Vazquez, Jean-Paul Linnartz

Precise  position  information  is  considered  as  the main  enabler  for  the  implementation  of  smart  manufacturing systems  in  Industry  4.0.  In ...


August 2021

Benefits of MIMO Mode Switching, Angular Diversity and Multiuser Multiplexing for LiFi

Sepideh Mohammadi Kouhini, Volker Jungnickel, Ronald Freund, Dominic Schulz, Peter Hellwig

We report on the first real-time experiments with distributed MIMO and multiple users for LiFi. MIMO mode switching and angular diversity are beneficial for robust-ness. Multiuser multiplexing helps in scenarios where users have complementary...


August 2021

Distributed MIMO Experiment Using LiFi Over Plastic Optical Fiber

Sepideh Mohammadi Kouhini, Volker Jungnickel, Ronald Freund, Sreelal Maravanchery Mana, Sepideh Mohammadi Kouhini, Jean-Paul Linnartz , Carina Ribeiro Barbio Corrêa, Eduward Tangdiongga, Thiago Cunha, Xiong Den

This  paper  shows  the  feasibility  of  a  networked LiFi  system  using  a  distributed  multiple-input  multiple-output(MIMO)  link  for  optical ...


August 2021

Deep Convolutional Neural Network for Network-wide QoT Estimation

Pooyan Safari, Johannes Fischer, Mohammad Behnam Shariati, Geronimo Bergk

We propose a novel Deep Convolutional Neural Network formulation for network-wide QoT classification tasks and show its effectiveness for networks with significant topological differences. Our formulation achieves ~99% accuracy on large and...



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