@inproceedings{29770,
  author       = {{Abughannam, Saed and Kruse, Stephan and Iftekhar, Mohammed and Scheytt, J. Christoph}},
  booktitle    = {{German Microwave Conference 2022 (GeMiC 2022)}},
  title        = {{{Design and Measurements of a Low-power Low-Date-rate Direct-detection Wireless Receiver with Improved Co-channel Interference Robustness}}},
  year         = {{2022}},
}

@article{34232,
  abstract     = {{<jats:p>In this paper, the theory of phase-locking of a microwave oscillator on the interharmonics, i.e. non-integer harmonics, of the repetition rate of the optical pulse train of a mode-locked laser (MLL) is developed. A balanced optical microwave phase detector (BOMPD) is implemented using a balanced Mach-Zehnder modulator and is employed to discriminate the phase difference between the envelope of the optical pulses and the microwave oscillator. It is shown mathematically that the inherent nonlinear properties of BOMPD with respect to the microwave excitation amplitude can be used for interharmonic locking. The characteristic functions of the phase detector for interharmonic locking are derived analytically and are compared with the measurement results. An opto-electronic phase-locked loop (OEPLL) is demonstrated whose output frequency locks on interharmonics of the MLL repetition rate when an appropriate modulator bias and sufficient RF amplitude are applied. Thus, for the first time theory and experiment of reliable locking on interharmonics of the repetition rate of a MLL are presented.</jats:p>}},
  author       = {{Bahmanian, Meysam and Kress, Christian and Scheytt, J. Christoph}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  number       = {{5}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Locking of microwave oscillators on the interharmonics of mode-locked laser signals}}},
  doi          = {{10.1364/oe.451894}},
  volume       = {{30}},
  year         = {{2022}},
}

@inproceedings{34233,
  author       = {{Singh, Karanveer and Kress, Christian and Mandalawi, Younus and Misra, Arijit and Preussler, Stefan and Scheytt, J. Christoph and Schneider, Thomas}},
  booktitle    = {{Next-Generation Optical Communication: Components, Sub-Systems, and Systems XI}},
  editor       = {{Li, Guifang and Nakajima, Kazuhide}},
  publisher    = {{SPIE}},
  title        = {{{Analysis of the effect of jitter and non-idealities on photonic digital-to-analog converters based on Nyquist pulses}}},
  doi          = {{10.1117/12.2609501}},
  year         = {{2022}},
}

@inproceedings{34234,
  author       = {{Singh, Karanveer and Meier, Janosch and Kress, Christian and Misra, Arijit and Schwabe, Tobias and Preussler, Stefan and Scheytt, J. Christoph and Schneider, Thomas}},
  booktitle    = {{Next-Generation Optical Communication: Components, Sub-Systems, and Systems XI}},
  editor       = {{Li, Guifang and Nakajima, Kazuhide}},
  publisher    = {{SPIE}},
  title        = {{{Emulation of integrated high-bandwidth photonic AWG using low-speed electronics}}},
  doi          = {{10.1117/12.2609416}},
  year         = {{2022}},
}

@article{34235,
  abstract     = {{<jats:p>We demonstrate for the first time, to the best of our knowledge, reconfigurable and real-time orthogonal time-domain detection of a high-bandwidth Nyquist signal with a low-bandwidth silicon photonics Mach-Zehnder modulator based receiver. As the Nyquist signal has a rectangular bandwidth, it can be multiplexed in the wavelength domain without any guardband as a part of a Nyquist-WDM superchannel. These superchannels can be additionally multiplexed in space and polarization. Thus, the presented demonstration can open a new possibility for the detection of multidimensional parallel data signals with silicon photonics. No external pulse source is needed for the receiver, and frequency-time coherence is used to sample the incoming Nyquist signal with orthogonal sinc-shaped Nyquist pulse sequences. All parameters are completely tunable in the electrical domain. The feasibility of the scheme is demonstrated through a proof-of-concept experiment over the entire C-band (1530 nm–1560 nm), employing a 24 Gbaud Nyquist QPSK signal due to experimental constraints on the transmitter side electronics. However, the silicon Mach-Zehnder modulator with a 3-dB bandwidth of only 16 GHz can process Nyquist signals of 90 GHz optical bandwidth, suggesting a possibility to detect symbol rates up to 90 GBd in an integrated Nyquist receiver.</jats:p>}},
  author       = {{Misra, Arijit and Kress, Christian and Singh, Karanveer and Meier, Janosch and Schwabe, Tobias and Preussler, Stefan and Scheytt, J. Christoph and Schneider, Thomas}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  number       = {{8}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Reconfigurable and real-time high-bandwidth Nyquist signal detection with low-bandwidth in silicon photonics}}},
  doi          = {{10.1364/oe.454163}},
  volume       = {{30}},
  year         = {{2022}},
}

@inproceedings{34236,
  abstract     = {{<jats:p>We report for the first time, inter-symbol-interference (ISI) free demultiplexing of Nyquist optical time division multiplexed (OTDM) signals using a reconfigurable orthogonal sinc-pulse sampling enabled by silicon photonic Mach-Zehnder Modulators.</jats:p>}},
  author       = {{Misra, Arijit and Singh, Karanveer and Meier, Janosch and Kress, Christian and Schwabe, Tobias and Preussler, Stefan and Scheytt, J. Christoph and Schneider, Thomas}},
  booktitle    = {{Conference on Lasers and Electro-Optics}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Flexible Time-Domain De-Multiplexing of Nyquist OTDM Channels by Orthogonal Sampling in Silicon Photonics}}},
  doi          = {{10.1364/cleo_si.2022.sth5m.2}},
  year         = {{2022}},
}

@article{34230,
  abstract     = {{We present the design and experimental characterization of a silicon nitride pulse interleaver based on coupled resonator optical waveguide filters. In order to achieve a targeted free spectral range of 1.44 THz, which is large given the reduced optical confinement of the silicon nitride platform, individual ring resonators are designed with tapered waveguides. Its application to time-interleaved photonically-assisted ADCs is analyzed by combining experimental characterization of the photonic integrated circuit with a comprehensive model of the entire ADC. The impact of fundamental signal distortion and noise sources affecting the converter is investigated and suitable equalization techniques at the digital signal processing level are evaluated. The novel application of a simple but powerful equalization filter in the DSP domain allows for a significant improvement of the digitized signal SNR. An ENOB of 5 over a 75 GHz bandwidth (150 GS/s) and an ENOB of 4.3 over a 100 GHz bandwidth (200 GS/s) are expected to be achievable with compact and off-the-shelf single-section semiconductor mode locked lasers, that can be further improved with lower noise light sources.}},
  author       = {{Zazzi, Andrea and Müller, Juliana and Ghannam, Ibrahim and Battermann, Moritz and Rajeswari, Gayatri Vasudevan and Weizel, Maxim and Scheytt, J. Christoph and Witzens, Jeremy}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  number       = {{3}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Wideband SiN pulse interleaver for optically-enabled analog-to-digital conversion: a device-to-system analysis with cyclic equalization}}},
  doi          = {{10.1364/oe.441406}},
  volume       = {{30}},
  year         = {{2022}},
}

@article{34239,
  author       = {{Bahmanian, Meysam and Scheytt, J. Christoph}},
  issn         = {{0018-9480}},
  journal      = {{IEEE Transactions on Microwave Theory and Techniques}},
  number       = {{10}},
  pages        = {{4422--4435}},
  publisher    = {{Institute of Electrical and Electronics Engineers (IEEE)}},
  title        = {{{Noise Processes and Nonlinear Mechanisms in Optoelectronic Phase-Locked Loop Using a Balanced Optical Microwave Phase Detector}}},
  doi          = {{10.1109/tmtt.2022.3197621}},
  volume       = {{70}},
  year         = {{2022}},
}

@article{30210,
  abstract     = {{Lithium niobate on insulator (LNOI) has a great potential for photonic integrated circuits, providing substantial versatility in design of various integrated components. To properly use these components in the implementation of different quantum protocols, photons with different properties are required. In this paper, we theoretically demonstrate a flexible source of correlated photons built on the LNOI waveguide of a special geometry. This source is based on the parametric down-conversion (PDC) process, in which the signal and idler photons are generated at the telecom wavelength and have different spatial profiles and polarizations, but the same group velocities. Distinguishability in polarizations and spatial profiles facilitates the routing and manipulating individual photons, while the equality of their group velocities leads to the absence of temporal walk-off between photons. We show how the spectral properties of the generated photons and the number of their frequency modes can be controlled depending on the pump characteristics and the waveguide length. Finally, we discuss special regimes, in which narrowband light with strong frequency correlations and polarization-entangled Bell states are generated at the telecom wavelength.}},
  author       = {{Ebers, Lena and Ferreri, Alessandro and Hammer, Manfred and Albert, Maximilian and Meier, Cedrik and Förstner, Jens and Sharapova, Polina R.}},
  issn         = {{2515-7647}},
  journal      = {{Journal of Physics: Photonics}},
  keywords     = {{tet_topic_waveguide}},
  pages        = {{025001}},
  publisher    = {{IOP Publishing}},
  title        = {{{Flexible source of correlated photons based on LNOI rib waveguides}}},
  doi          = {{10.1088/2515-7647/ac5a5b}},
  volume       = {{4}},
  year         = {{2022}},
}

@inproceedings{40212,
  author       = {{Haucke-Korber, Barnabas and Schenke, Maximilian and Wallscheid, Oliver}},
  booktitle    = {{IKMT 2022; 13. GMM/ETG-Symposium}},
  pages        = {{1--6}},
  title        = {{{Reinforcement Learning-Based Deep Q Direct Torque Control with Adaptable Switching Frequency Towards Six-Step Operation of Permanent Magnet Synchronous Motors}}},
  year         = {{2022}},
}

@inproceedings{6553,
  author       = {{Claes, Leander and Feldmann, Nadine and Schulze, Veronika and Jurgelucks, Benjamin and Walther, Andrea and Henning, Bernd}},
  booktitle    = {{Fortschritte der Akustik - DAGA 2022}},
  location     = {{Stuttgart}},
  pages        = {{1326--1329}},
  title        = {{{Identification of piezoelectric material parameters using optimised multi-electrode specimens}}},
  year         = {{2022}},
}

@misc{6558,
  author       = {{Friesen, Olga and Claes, Leander and Feldmann, Nadine and Henning, Bernd}},
  title        = {{{Estimation of piezoelectric material parameters of ring-shaped specimens}}},
  year         = {{2022}},
}

@inproceedings{26033,
  author       = {{Zeipert, Henning and Johannesmann, Sarah and Nicolai, Marcel and Lugovtsova, Yevgeniya and Prager, Jens and Henning, Bernd}},
  booktitle    = {{Fortschritte der Akustik - DAGA 2021}},
  location     = {{Wien}},
  title        = {{{Quantifying the coupling strength of adhesively bonded materials by investigating mode repulsion regions}}},
  year         = {{2021}},
}

@inproceedings{27847,
  author       = {{Lugovtsova, Yevgeniya and Zeipert, Henning and Johannesmann, Sarah and Nicolai, Marcel and Prager, Jens and Henning, Bernd}},
  booktitle    = {{МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ В ЕСТЕСТВЕННЫХ НАУКАХ - XXX Всероссийская школа-конференция}},
  location     = {{Perm}},
  title        = {{{К ОПРЕДЕЛЕНИЮ ПРОЧНОСТИ КЛЕЕВОГО СОЕДИНЕНИЯ В МНОГОСЛОЙНЫХ МАТЕРИАЛАХ ПУТЕМ ИССЛЕДОВАНИЯ ОБЛАСТЕЙ РАСТАЛКИВАНИЯ БЕГУЩИХ УПРУГИХ ВОЛН}}},
  year         = {{2021}},
}

@article{21065,
  abstract     = {{The machine recognition of speech spoken at a distance from the microphones, known as far-field automatic speech recognition (ASR), has received a significant increase of attention in science and industry, which caused or was caused by an equally significant improvement in recognition accuracy. Meanwhile it has entered the consumer market with digital home assistants with a spoken language interface being its most prominent application. Speech recorded at a distance is affected by various acoustic distortions and, consequently, quite different processing pipelines have emerged compared to ASR for close-talk speech. A signal enhancement front-end for dereverberation, source separation and acoustic beamforming is employed to clean up the speech, and the back-end ASR engine is robustified by multi-condition training and adaptation. We will also describe the so-called end-to-end approach to ASR, which is a new promising architecture that has recently been extended to the far-field scenario. This tutorial article gives an account of the algorithms used to enable accurate speech recognition from a distance, and it will be seen that, although deep learning has a significant share in the technological breakthroughs, a clever combination with traditional signal processing can lead to surprisingly effective solutions.}},
  author       = {{Haeb-Umbach, Reinhold and Heymann, Jahn and Drude, Lukas and Watanabe, Shinji and Delcroix, Marc and Nakatani, Tomohiro}},
  journal      = {{Proceedings of the IEEE}},
  number       = {{2}},
  pages        = {{124--148}},
  title        = {{{Far-Field Automatic Speech Recognition}}},
  doi          = {{10.1109/JPROC.2020.3018668}},
  volume       = {{109}},
  year         = {{2021}},
}

@article{21067,
  abstract     = {{Acoustic waves in plates have proven a viable tool for testing and material characterisation purposes. There are a multitude of options for excitation and detection of theses waves, such as optical and piezoelectric systems. While optical systems, with thermoelastic excitation and interferometric detection, have the benefit of being contactless, they usually require rather complex and expensive experimental setups. Piezoelectric systems are more easily realised but require direct contact with the specimen and usually have a limited bandwidth, especially in case of piezoelectric excitation. In this work, the authors compare the properties of piezoelectric and optical detection methods for broad-band acoustic signals. The shape (e. g. the displacement) of a propagating plate wave is given by its frequency and wave number, allowing to investigate correlations between mode shapes and received signal strengths. This is aided by evaluations in normalised frequency and wavenumber space, facilitating comparisons of different specimens. Further, the authors explore possibilities to utilise the specific properties of the detection methods to determine acoustic material parameters.}},
  author       = {{Claes, Leander and Schmiegel, Hanna and Grünsteidl, Clemens and Johannesmann, Sarah and Webersen, Manuel and Henning, Bernd}},
  issn         = {{2196-7113}},
  journal      = {{tm - Technisches Messen}},
  number       = {{3}},
  pages        = {{147--155}},
  title        = {{{Investigating peculiarities of piezoelectric detection methods for acoustic plate waves in material characterisation applications}}},
  doi          = {{10.1515/teme-2020-0098}},
  volume       = {{88}},
  year         = {{2021}},
}

@article{21082,
  author       = {{Itner, Dominik and Gravenkamp, Hauke and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}},
  issn         = {{1617-7061}},
  journal      = {{PAMM}},
  title        = {{{Simulation of guided waves in cylinders subject to arbitrary boundary conditions for applications in material characterization}}},
  doi          = {{10.1002/pamm.202000232}},
  year         = {{2021}},
}

@phdthesis{21183,
  abstract     = {{Die präzise Kenntnis der Eigenschaften verwendeter Materialien hat große Bedeutung für den Entwurf technischer Systeme aller Art, aber auch für die Überwachung solcher Systeme im Betrieb. Für verschiedene physikalische Eigenschaften, Betriebsbedingungen und Materialklassen werden daher geeignete messtechnische Verfahren zur Materialcharakterisierung benötigt. In der vorliegenden Arbeit wird ein Verfahren zur ultraschallbasierten Charakterisierung der mechanischen Eigenschaften von homogenen und faserverstärkten thermoplastischen Polymeren unter Berücksichtigung der Richtungsabhängigkeit vorgestellt. Plattenförmige Probekörper werden dazu mittels Laser-Pulsen hoher Energie breitbandig angeregt und die resultierenden akustischen Lamb-Wellen aufgezeichnet. Auf Basis der dispersiven Eigenschaften der detektierten Wellenleitermoden werden in einem inversen Verfahren die Parameter eines linear-elastischen Materialmodells identifiziert. Darüber hinaus wird ein Verfahren zur vollständigen Charakterisierung der Richtungsabhängigkeit in orthotropen Materialien wie Faserverbundwerkstoffen unter Verwendung eines zweidimensionalen Simulationsmodells vorgestellt. Das Messverfahren wird anhand einer Untersuchungsreihe an künstlich gealterten Polymer- und Faserverbundwerkstoffen verifiziert und die Übertragbarkeit der Ergebnisse auf den quasistatischen Fall betrachtet. Im Vergleich mit den Ergebnissen mechanischer Zugversuche werden die Voraussetzungen und Einschränkungen, insbesondere durch die Annahme eines ideal-elastischen Materialmodells, diskutiert.}},
  author       = {{Webersen, Manuel}},
  publisher    = {{Universitätsbibliothek Paderborn}},
  title        = {{{Zerstörungsfreie Charakterisierung der elastischen Materialeigenschaften thermoplastischer Polymerwerkstoffe mittels Ultraschall}}},
  doi          = {{10.17619/UNIPB/1-1088}},
  year         = {{2021}},
}

@misc{21564,
  author       = {{Itner, Dominik and Gravenkamp, Hauke and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}},
  title        = {{{On the forward simulation and cost functions for the ultrasonic material characterization of polymers }}},
  year         = {{2021}},
}

@article{23791,
  author       = {{Johannesmann, Sarah and Claes, Leander and Henning, Bernd}},
  journal      = {{tm - Technisches Messen}},
  number       = {{s1}},
  pages        = {{s28--s33}},
  publisher    = {{Walter de Gruyter {GmbH}}},
  title        = {{{Lamb wave based approach to the determination of elastic and viscoelastic material parameters}}},
  doi          = {{10.1515/teme-2021-0070}},
  volume       = {{88}},
  year         = {{2021}},
}