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Optimization of local backside released micro-ring resonators for sensing applications using silicon photonic integrated circuits in a SOI technology
No full textPhotonic micro-ring resonators (MRR) are widely studied for their high sensitivity across applications like environmental monitoring, healthcare, and chemical analysis. Their evanescent field sensing requires partially unembedded waveguides compatible with CMOS processing. Our approach uses local backside etching with an additional buried oxide (BOX) etch to release waveguides while preserving the back-end of line (BEOL) structure, enabling spatial separation of the sensing area and electronics. The BOX etch critically affects sensor performance, as waveguide surface roughness can alter MRR properties and coupling. We analyzed MRR design variations, comparing wet and dry etching techniques for their effects on optical performance across rib and strip waveguides in quasi-TE and quasi-TM modes. Wafer-level measurements show that backside-released MRR achieve high extinction ratios with slightly reduced quality factors, advancing high-sensitivity photonic sensors
Multichannel real-time detection of biomarkers with highly miniaturized photonic microchips
No full textThe development of novel photonic integrated microchips (PIC) is a promising approach to allow for the convenient detection of key biomarkers in complex matrices through multichannel real-time analysis in a highly compact package. This study reports the successful development and application of a backside released CMOS chip designed for the multichannel real-time detection of biomarkers. Operating at the C-band at approx. 1550 nm, the microchip features three dedicated detection sensors in addition to a reference sensor, enabling simultaneous analysis of multiple biomarkers. The compact and highly miniaturized design of this microchip, with a footprint of just 1 mm², positions it as promising candidate for point-of-care diagnostics and personalized medicine applications. This technology opens a path to transform biomarker detection across various medical fields, offering rapid, reliable, and cost-effective diagnostic solutions. In conclusion, the presented multichannel photonic microchips signify a substantial leap forward in real-time biomarker detection, providing a highly capable platform for future research and clinical applications
Objective validation for short-term material flow simulation
No full textMaterial flow simulation, by means of discrete event simulation (DES), is utilized in various industries to support production planning and control. This is due to the fact that changes to manufacturing systems and production strategies can be virtually examined before actual implementation. Since the manual development and repeated adjustment of simulation models is time-consuming and error-prone, numerous studies suggest computerized model generation and synchronization. However, validation of such generated or synchronized models is rarely considered. Here, we present an extendible objective validation technique for the repeated short-term simulation of a generated model. To illustrate this, the technique is applied to a high-volume automotive production line and a series of simulation cycles
Reflectometric method for measuring residual oxides in through-silicon vias for 3D chip integration
No full textA significant aspect of fabricating 3D chip architectures is ensuring proper contact between the different layers of the chip, which often requires removing the underside of isolation layers before filling vias with conductive material. Currently, scanning electron microscopy is the established method for investigating such structures. In this paper, we propose a rapid, non-destructive optical analysis technique for the simultaneous measurement of through-silicon vias (TSV) depths, silicon wafer thickness, and residual oxide thickness. The proposed method utilizes Fourier peak shift analysis (FPSA) of reflectance measurements in the near-infrared (1200 nm—2200 nm) spectral regions. The application of FPSA to representative samples taken from a commercial TSV integration process for MEMS and CMOS fabrication demonstrated good agreement with reference scanning electron microscopy measurements, confirming the feasibility of the method for in-line and in-situ metrology. The results indicate that FPSA has great potential for real-time process monitoring and control during 3D chip manufacturing
Agentic Recommender System Concept for Sustainable Knowledge Management
No full textUnternehmen stehen vor erheblichen Herausforderungen beim Erhalt, bei der Nutzung und Weitergabe zentralen Wissens. Demografischer Wandel, zunehmender Mitarbeiterfluktuation und steigende organisatorische Komplexität erschweren klassische Dokumentations- und Austauschprozesse, welche auf erhebliche Mitarbeitendenmitwirkung angewiesen sind. Mithilfe generativer KI und agentischer Recommender-Systeme lassen sich diese Hindernisse überwinden, indem wichtiges Wissen ”on-the-fly“ und weitestgehend automatisiert erfasst wird. Ein zentrales Element bildet hierbei die Kombination aus semantischen Embeddings, einer Graphdatenbank und spezialisierten KI-Agenten, die Dokumente und Chatverläufe analysieren, Mitarbeiter gezielt mit Vorschlägen unterstützen und Wissen so kontinuierlich aktualisieren. So entsteht eine effektive Wissenskultur mit niedrigen Barrieren für die Nutzung dank minimalem Mehraufwand für die menschlichen Nutzer.Companies face considerable challenges in retaining, utilising and passing on key knowledge. Demographic change, increasing employee turnover and growing organisational complexity are making traditional documentation and exchange processes, which rely heavily on employee participation, more difficult. With the help of generative AI and agentic recommender systems, these obstacles can be overcome by capturing important knowledge ‘on the fly’ and in a largely automated manner. A central element here is the combination of semantic embeddings, a graph database and specialised AI agents that analyse documents and chat histories, provide employees with targeted support in the form of suggestions and thus continuously update knowledge. This creates an effective knowledge culture with low barriers to use thanks to minimal additional effort for human users
New insights into the ‘Indonesian way’ of managing international business negotiations
No full textIndonesia has enjoyed impressive economic growth since the early 2000s and consequently attracted significant business interest from western companies. Yet, the Indonesian business context has also been notoriously impacted by corruption, which presents a serious challenge for international business negotiations. Interestingly, in scholarly research little is known about the indigenous management practices within the Indonesian context. This study therefore investigates indigenous management practices during international business negotiations taking place in the emerging market of Indonesia, that may determine the success or failure of multinational corporations’ negotiations. We conduct an inductive analysis of rich and context-specific data generated through 55 in-depth interviews of Indonesian and non-Indonesian managers. We discover: (1) the importance of perantara as a third-party agent, specific to Indonesia, that operates as a backchannel conduit for communication between parties and is essential for progressing to the face-to-face negotiation stage; and (2) the unique relationship-building process essential for business negotiations in Indonesia, which moves from task orientation to relationship-building orientation. To the best of our knowledge, our study is one of the first to tackle such specific indigenous management behaviours during international business negotiation in Indonesia from a context-specific insider’s perspective. This study provides useful insights for managers of foreign multinational corporations on how to manage certain indigenous Indonesian management behaviours if they are to achieve successful investment outcomes
AD3D - Eine automatisierte Toolchain für das 3D-Drucken
No full textDer technische Fortschritt hat dazu geführt, dass die Kosten für das automatisierte Drucken von Emblemen, Anhängern sowie allgemein gedruckten Prototypen stark gefallen sind. Dies geschah insbesondere auch vor dem Hintergrund eines Wandels der Industrie hin zu einer modernen Industrie 4.0. In dieser Arbeit wird ein neuer Ansatz für das automatische 3D-Drucken eines Logos präsentiert, welches als Pixelgrafik vorliegt. Die vorgeschlagene Prozesskette erzeugt hierbei final den G-code zum Drucken. Dabei sind seitens des Users wenige Eingaben erforderlich
Fahrradstraßen als Instrument zur Förderung des Umweltverbundes? Eine Untersuchung zum Einfluss von Fahrradstraßen auf den Fuß- und Linienbusverkehr
No full textImmer mehr Städte und Kommunen erkennen, dass Fahrradstraßen eine kostengünstige und schnell umzusetzende Maßnahme darstellen, um den Radverkehr zu fördern. Gleichzeitig herrscht in urbanen Räumen häufig eine große Flächenkonkurrenz, die eine Überlagerung verschiedener Verkehrsnetze und das Aufeinandertreffen unterschiedlicher Nutzungsansprüche bedingt. Da ein gegenseitiges Ausspielen der Verkehrsmittel des Umweltverbundes im Sinne der Mobilitätswende vermieden werden muss, untersucht die vorliegende Arbeit, ob und unter welchen Voraussetzungen Fahrradstraßen nicht nur für den Radverkehr, sondern auch für den Fußverkehr und Linienbusverkehr Vorteile bringen können. Dazu wurde eine empirische Untersuchung in Berlin, Frankfurt am Main, Münster und Utrecht (NL) durchgeführt, bei der in ausgewählten Fahrradstraßen sowohl qualitative als auch quantitative Methoden zur Anwendung kamen. Mithilfe von leitfadengestützten Expert*inneninterviews wurde ermittelt, welche Anforderungen der Fuß- und Linienbusverkehr an Fahrradstraßen hat und inwiefern diese in der Planung berücksichtigt werden. Stationäre Verkehrsbeobachtungen gaben darüber hinaus Aufschluss über Interaktionen zwischen dem Fuß- und Radverkehr an Querungsstellen. In einer ergänzenden Straßenbefragung wurden Passant*innen zu ihrer Wahrnehmung der Verkehrssicherheit und Aufenthaltsqualität befragt. Um den Einfluss des Radverkehrs auf den Linienbusverkehr in Fahrradstraßen zu untersuchen, wurden außerdem Busmitfahrten durchgeführt.
In der Auswertung der erhobenen Daten wurde deutlich, dass der Linienbusverkehr aufgrund der Reduzierung des Kfz-Verkehrsaufkommens in der Regel von Fahrradstraßen profitiert. Verzögerungen im Betriebsablauf durch den Radverkehr sind zwar möglich, fallen aber kaum ins Gewicht. Insgesamt zeigte sich die Kombination von Rad- und Busverkehr harmonisch, auch aus Sicht von Busfahrenden und Verkehrsbetrieben. Für den Fußverkehr ergeben sich ebenfalls Vorteile. Neben der geringeren Lärmbelastung tragen oftmals weitere Maßnahmen wie breite Gehwege und Grünelemente zu einer höheren Aufenthaltsqualität bei. Eine ausgeprägte Barrierewirkung von Fahrradstraßen für den Fußverkehr konnte nicht festgestellt werden. Vielmehr verliefen die beobachteten Interaktionen zwischen Radfahrenden und Zufußgehenden überwiegend konfliktfrei.More and more cities and local authorities in Germany are recognising bicycle lanes (Fahrradstraßen) as a cost-effective and quick-to-implement measure to promote cycling. At the same time, there is often a great deal of competition for space in urban areas, which results in the overlapping of different transport networks and the clash of different utilisation requirements. As it is important to avoid playing off the different modes of transport in the interests of the ‘Mobilitätswende, this study investigates whether and under which circumstances bicycle lanes can bring benefits not only for cycling, but also for walking and regular bus services. To answer this question, an empirical study was carried out in Berlin, Frankfurt am Main, Münster and Utrecht (NL), in which both qualitative and quantitative methods were used in selected bicycle lanes. Guided interviews with experts were used to determine the requirements of pedestrians and regular bus services for bicycle lanes and the extent to which these are taken into account in the planning. Stationary traffic observations also provided information about interactions between pedestrians and cyclists at crossing points. In a supplementary street survey, pedestrians were asked about their perception of road safety and quality of stay. In order to analyse the influence of cycling on bus traffic in bicycle lanes, bus rides were carried out in addition.
The analysis of the collected data clearly showed that regular bus services generally benefit from bicycle lanes due to the reduction in motor vehicle traffic. Although delays in operations due to cycle traffic are possible, they are hardly significant. Overall, the combination of cycle and bus traffic proved to be harmonious, also from the point of view of bus drivers and transport companies. Bicycle lanes also offer advantages for pedestrians. In addition to reduced noise pollution, other measures such as wide sidewalks and green elements often contribute to a higher quality of stay. A pronounced barrier effect of bicycle lanes for pedestrians was not observed. On the contrary, the interactions observed between cyclists and pedestrians were largely conflict-free
Irradiation-induced enhancement of Fe and Al magnetic polarizations in Fe60Al40 films
No full textThe rise of Fe magnetic moment, changes in Al electronic structure and a variation of Al magnetic polarization in thin films of transition metal aluminide Fe60Al40 have been probed through the order-disorder phase transition by soft X-ray absorption spectroscopy and X-ray resonant magnetic reflectivity in the extreme ultraviolet regime. In a course of the transition induced by 20 keV Ne+ irradiation with low fluences (1014 ions·cm-2), X-ray magnetic circular dichroism spectra taken at the Fe L2,3 absorption edges at room and low temperatures revealed a pronounced increase of Fe 3d states spin-polarization. X-ray resonant magnetic reflectivity applied to the Al L2,3 and Fe M2,3 edges allowed to detect the magnetic polarization of Al atoms in the films. The changes in Al electronic structure have been seen by alteration of Al K edge X-ray absorption near edge structure. A difference in anisotropy fields for films before and after irradiation has been observed by element-specific hysteresis loops recorded at low temperatures in absorption and reflection geometries at the Fe L2,3 and M2,3 edges, respectively. An attempt to reduce the top oxide layer by an inductively coupled hydrogen plasma has shown a possibility to recover the chemically ordered phase
Bright continuously tunable vacuum ultraviolet source for ultrafast spectroscopy
No full textUltrafast electron dynamics drive phenomena such as photochemical reactions, catalysis, and light harvesting. To capture such dynamics in real-time, femtosecond to attosecond light sources are extensively used. However, an exact match between the excitation photon energy and a characteristic resonance is crucial. High-harmonic generation sources are advantageous in terms of pulse duration but limited in spectral tunability in the vacuum ultraviolet range. Here, we present a monochromatic femtosecond source continuously tunable around 21eV photon energy utilizing the second harmonic of an optical parametric chirped pulse amplification laser system to drive high-harmonic generation. The unique tunability of the source is verified in an experiment probing the interatomic Coulombic decay in doped He nanodroplets across the He absorption bands. Moreover, we achieved intensities sufficient for driving collective processes in multiply excited helium nanodroplets, which have been previously observed only at free electron lasers