TY - JOUR AU - Kunnathully, Vinay S. AU - Riedl, Thomas AU - Trapp, Alexander AU - Langer, Timo AU - Reuter, Dirk AU - Lindner, Jörg ID - 34091 JF - Journal of Crystal Growth KW - Materials Chemistry KW - Inorganic Chemistry KW - Condensed Matter Physics SN - 0022-0248 TI - InAs heteroepitaxy on nanopillar-patterned GaAs (111)A VL - 537 ER - TY - JOUR AU - Riedl, Thomas AU - Lindner, Jörg ID - 34090 JF - Solid State Communications KW - Materials Chemistry KW - Condensed Matter Physics KW - General Chemistry SN - 0038-1098 TI - Applicability of molecular statics simulation to partial dislocations in GaAs VL - 314-315 ER - TY - JOUR AU - Riedl, Thomas AU - Lindner, Jörg ID - 34089 JF - Solid State Communications KW - Materials Chemistry KW - Condensed Matter Physics KW - General Chemistry SN - 0038-1098 TI - Applicability of molecular statics simulation to partial dislocations in GaAs VL - 314-315 ER - TY - CONF AB - Novel analog-to-digital converter (ADC) architectures are motivated by the demand for rising sampling rates and effective number of bits (ENOB). The main limitation on ENOB in purely electrical ADCs lies in the relatively high jitter of oscillators, in the order of a few tens of fs for state-of-the-art components. When compared to the extremely low jitter obtained with best-in-class Ti:sapphire mode-locked lasers (MLL), in the attosecond range, it is apparent that a mixed electrical-optical architecture could significantly improve the converters' ENOB. We model and analyze the ENOB limitations arising from optical sources in optically enabled, spectrally sliced ADCs, after discussing the system architecture and implementation details. The phase noise of the optical carrier, serving for electro-optic signal transduction, is shown not to propagate to the reconstructed digitized signal and therefore not to represent a fundamental limit. The optical phase noise of the MLL used to generate reference tones for individual slices also does not fundamentally impact the converted signal, so long as it remains correlated among all the comb lines. On the other hand, the timing jitter of the MLL, as also reflected in its RF linewidth, is fundamentally limiting the ADC performance, since it is directly mapped as jitter to the converted signal. The hybrid nature of a photonically enabled, spectrally sliced ADC implies the utilization of a number of reduced bandwidth electrical ADCs to convert parallel slices, resulting in the propagation of jitter from the electrical oscillator supplying their clock. Due to the reduced sampling rate of the electrical ADCs, as compared to the overall system, the overall noise performance of the presented architecture is substantially improved with respect to a fully electrical ADC. AU - Zazzi, Andrea AU - Müller, Juliana AU - Gudyriev, Sergiy AU - Marin-Palomo, Pablo AU - Fang, Dengyang AU - Scheytt, Christoph AU - Koos, Christian AU - Witzens, Jeremy ID - 24020 T2 - 21. ITG-Fachtagung Photonische Netze TI - Mode-locked laser timing jitter limitation in optically enabled frequency-sliced ADCs ER - TY - JOUR AB - The effect of phase noise introduced by optical sources in spectrally-sliced optically enabled DACs and ADCs is modeled and analyzed in detail. In both data converter architectures, a mode-locked laser is assumed to provide an optical comb whose lines are used to either synthesize or analyze individual spectral slices. While the optical phase noise of the central MLL line as well as of other optical carriers used in the analyzed system architectures have a minor impact on the system performance, the RF phase noise of the MLL fundamentally limits it. In particular, the corresponding jitter of the MLL pulse train is transferred almost one-to-one to the system-level timing jitter of the data converters. While MLL phase noise can in principle be tracked and removed by electronic signal processing, this results in electric oscillator phase noise replacing the MLL jitter and is not conducive in systems leveraging the ultra-low jitter of low-noise mode-locked lasers. Precise analytical models are derived and validated by detailed numerical simulations. AU - Zazzi, Andrea AU - Müller, Juliana AU - Gudyriev, Sergiy AU - Marin-Palomo, Pablo AU - Fang, Dengyang AU - Scheytt, Christoph AU - Koos, Christian AU - Witzens, Jeremy ID - 24025 JF - Opt. Express TI - Fundamental limitations of spectrally-sliced optically enabled data converters arising from MLL timing jitter VL - 28 ER - TY - CONF AB - A 28 Gbps NRZ bang-bang clock and data recovery (CDR) chip for 100G PSM4 is presented. It exhibits an adaptable loop filter transfer function with independently tunable proportional and integral parameters. This allows to optimize the jitter transfer, jitter tolerance, and locking range of the CDR according to system requirements. The CDR represents a key component for a single-chip 8-channel electronic-photonic PSM4 transceiver. A CDR chip was manufactured in a 0.25 μm monolithic photonic BiCMOS technology. The core chip area is 0.51 mm 2 and it dissipates 330 mW from 2.5 V and 3.3 V power supplies. AU - Iftekhar, Mohammed AU - Gudyriev, Sergiy AU - Scheytt, Christoph ID - 24028 T2 - 2020 IEEE 20th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF) TI - 28 Gbps Bang-Bang CDR for 100G PSM4 with Independently Tunable Proportional and Integral Parameters of the Loop Filter in 0.25 µm Photonic BiCMOS Technology ER - TY - CONF AB - In this paper we present a new system concept for an optoelectronic wireless phased array system. Like in a conventional phased array system with optical carrier distribution, optical fibers are used to distribute the carrier from the basestation to the wireless frontends. However in contrast to prior concepts, we propose to use an optical IQ return path from the wireless frontends back to the basestation. Furthermore, we reuse the optical carrier signal for the IQ return path which allows to avoid local oscillator lasers in the wireless frontends and reduces the hardware effort significantly. The system concept allows to integrate all components of an optoelectronic wireless frontend in a single chip using silicon photonics technology. AU - Kruse, Stephan AU - Kress, Christian AU - Scheytt, Christoph AU - Kurz, Heiko G. AU - Schneider, Thomas ID - 24026 T2 - GeMiC 2020 - German Microwave Conference TI - Analysis and Simulation of a Wireless Phased Array System with Optical Carrier Distribution and an Optical IQ Return Path ER - TY - JOUR AU - Atorf, Bernhard AU - Mühlenbernd, Holger AU - Zentgraf, Thomas AU - Kitzerow, Heinz-Siegfried ID - 16301 IS - 6 JF - Optics Express SN - 1094-4087 TI - All-optical switching of a dye-doped liquid crystal plasmonic metasurface VL - 28 ER - TY - CONF AB - Recently it has been demonstrated that an optoelectronic phase-locked loop (OEPLL) using a mode-locked laser as a reference oscillator achieves significantly lower phase noise than conventional electronic frequency synthesizers. In this paper a concept for an OEPLL-based frequency synthesizer is presented and it is investigated how it can be used as a local oscillator (LO) for THz transceivers in order to improve the signal quality in THz wireless communications. The concept of the OEPLL is presented and it's measured phase noise is compared to the phase noise of a laboratory-grade electronic frequency synthesizer. The measured phase noise spectra of both synthesizers at 10 GHz are then used to model LO phase noise at 320 GHz. Based on models of generic zero-IF transmit and receive frontends, THz signals with different modulation formats and Baud rates are simulated at system level using the modeled LO phase noise for the two LO approaches. Finally, the results are compared. AU - Scheytt, Christoph AU - Wrana, Dominik AU - Bahmanian, Meysam AU - Kallfass, Ingmar ID - 24024 T2 - 2020 Third International Workshop on Mobile Terahertz Systems (IWMTS) TI - Ultra-Low Phase Noise Frequency Synthesis for THz Communications Using Optoelectronic PLLs ER - TY - CHAP AU - Lankeit, Elisa AU - Biehler, Rolf ED - Hausberger, T. ED - Bosch, M. ED - Chelloughi, F. ID - 35912 T2 - Proceedings of the Third Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2020, 12-19 September 2020) TI - “I only know the absolute value function”–About students’ concept images and example spaces concerning continuity and differentiability ER - TY - CHAP AU - Lankeit, Elisa AU - Bauer, T. AU - Biehler, Rolf ED - Siller, H.-S. ED - Weigel, W. ED - Wörler, J. F. ID - 35911 T2 - Beiträge zum Mathematikunterricht 2020 TI - Votingfragen in den Übungen zur Analysis – Wirkung verschiedener Einsatzszenarien ER - TY - GEN AU - Caruso, Carina ED - Zimmermann, Mirjam ED - Lindler, Heike ID - 35929 T2 - Das wissenschaftlich-religionspädagogische Lexikon im Internet TI - Praxissemester ER - TY - JOUR AU - Caruso, Carina ID - 35935 JF - katholisch.de, Kolumne „Mein Religionsunterricht“. TI - Der Weg zur Theologie-Professur ist hart – gerade für Religionslehrer! ER - TY - THES AU - Schwabl, Franziska ID - 35956 TI - Inszenierungen im digitalen Bild. Eine Rekonstruktion der Selfie-Praktiken Jugendlicher mittels der Dokumentarischen Bildinterpretation. ER - TY - JOUR AU - Schwabl, Franziska ID - 35968 JF - bwp@Berufs-und Wirtschaftspädagogik – online TI - Fotografien als Zugang zur Lebenswelt Jugendlicher. Eine Analyse der digitalen Inszenierungspraktiken Jugendlicher im berufsschulischen Übergangssystem. VL - 38 ER - TY - JOUR AU - Lünne, Steffen AU - Schnell, Susanne AU - Biehler, Rolf ID - 35701 IS - 5 JF - European Journal of Teacher Education KW - Education SN - 0261-9768 TI - Motivation of out-of-field teachers for participating in professional development courses in mathematics VL - 44 ER - TY - CHAP AU - Barzel, Bärbel AU - Biehler, Rolf ED - Zehetmeier, Stefan ED - Potari, Despina ED - Ribeiro, Miguel ID - 35808 T2 - Professional development and knowledge of mathematics teachers TI - Theory-Based Design of Professional Development for Upper Secondary Teachers–Focusing on the Content-Specific Use of Digital Tools ER - TY - CHAP AU - Biehler, Rolf AU - Durand-Guerrier, Viviane ED - Hausberger, T. ED - Bosch, M. ED - Chelloughi, F. ID - 35811 KW - Number Theory KW - Algebra KW - Discrete Mathematics KW - Logic KW - Research in University Mathematics Edcuation T2 - Proceedings of the Third Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2020, 12-19 September 2020) TI - University Mathematics Didactic Research on Number Theory, Algebra, Discrete Mathematics, Logic ER - TY - CHAP AU - Budde, Lea AU - Frischemeier, Daniel AU - Biehler, Rolf AU - Fleischer, Yannik AU - Gerstenberger, Dietrich AU - Podworny, Susanne AU - Schulte, Carsten ED - Arnold, P. ID - 35821 T2 - New Skills in the Changing World of Statistics Education: Proceedings of the Roundtable conference of the International Association for Statistical Education (IASE), July 2020 TI - Data Science Education in Secondary School: How to Develop Statistical Reasoning When Exploring Data Using CODAP ER - TY - CHAP AU - Biehler, Rolf AU - Kempen, Leander AU - Paravicini, Walther ED - Siller, H.-S. ED - Weigel, W. ED - Wörler, J. F. ID - 35819 T2 - Beiträge zum Mathematikunterricht 2020 TI - Hochschuldidaktik Mathematik: Fachbezogenes Design und empirische Studien ER -