@misc{BeyerHarendtKoschligetal.1998, author = {Beyer, Harald and Harendt, Andreas and Koschlig, Tobias and Rolle, Siegfried and Roß, Werner and Volkmann, Hans}, title = {Das Institut f{\"u}r Plasma- und Lasertechnik der Technischen Fachhochschule Wildau}, series = {Wissenschaftliche Beitr{\"a}ge 2/1998}, volume = {4}, journal = {Wissenschaftliche Beitr{\"a}ge 2/1998}, number = {2}, issn = {0949-8214}, doi = {10.15771/0949-8214_1998_2_3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-7488}, pages = {16 -- 23}, year = {1998}, abstract = {Am 31.12.1996 endete das Wissenschaftler-Integrations-Programm (WIP) in den neuen L{\"a}ndern. Es war angelegt worden, um Teilen der in der Akademie der Wissenschaften der DDR arbeitenden (und mehrfach positiv evaluierten) Wissenschaftlern eine {\"U}bergangsphase zu finanzieren, in der sie einerseits ihre Arbeit kontinuierlich fortsetzen konnten und andererseits die Integration in einer Hochschule erfolgen sollte, da die Forschungslandschaft der DDR an die bundesdeutschen Strukturen anzupassen waren. Das vorab auf zwei Jahre angelegte, 1992 gestartete Programm konnte bis 1996 verl{\"a}ngert werden, wenn es gelang, eine Hochschule zu finden, die bekundete, an einer Integration dieser Wissenschaftler in ihrer Einrichtung interessiert zu sein. Zielhochschule der Wissenschaftler in der von Prof. Dr. sc. H. G{\"u}ndel gegr{\"u}ndeten Gruppe, die sich in Fortf{\"u}hrung ihrer langj{\"a}hrigen Forschungst{\"a}tigkeit auf dem Gebiet der nichtthermischen Plasmen (auch Niedertemperaturplasmen), insbesondere zur Erzeugung von Laserlicht besch{\"a}ftigte und auch noch besch{\"a}ftigt, war die TFH Wildau. Dies war f{\"u}r eine Berliner Einrichtung einerseits ungew{\"o}hnlich, andererseits auch nahe: In der Gr{\"u}ndungsphase der TFH Wildau lag ein besonderes Schwergewicht auf den modernen Technologien, was sich auch dadurch ausdr{\"u}ckte, daß es einen Fachbereich Physikalische Technik gab, der heute im Fachbereich Ingenieur- und Wirtschaftsingenieurwesen als Studienrichtung weiter besteht. Da sich f{\"u}r die Zukunft eine immer breitere, auch ingenieurm{\"a}ßige Anwendung der Plasma- und Lasertechnik abzeichnet und an den Deutschen Fachhochschulen dieses Gebiet (insbesondere die Plasmatechnik) kaum in der Lehre vertreten wird, wurde von beiden Seiten - der TFH Wildau auf der einen und der sich damals noch als WIP AG Niedertemperaturplasmen bezeichnenden Gruppe aus Berlin auf der anderen - eine Integration in einem Institut f{\"u}r Plasma- und Lasertechnik (IPLT) der TFH Wildau im Fachbereich Physikalische Technik angestrebt.}, language = {de} } @misc{RichterBrzezinka1995, author = {Richter, Asta and Brzezinka, Klaus-Werner}, title = {Thin Film Deposition and Modification of Fullerenes by Laser Radiation}, series = {Wissenschaftliche Beitr{\"a}ge 1/1995}, volume = {1}, journal = {Wissenschaftliche Beitr{\"a}ge 1/1995}, number = {1}, issn = {0949-8214}, doi = {10.15771/0949-8214_1995_17}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-8118}, pages = {100 -- 103}, year = {1995}, abstract = {Laser ablation from solid fullerene pellet and textured graphite targets has been probed for deposition of thin fullerite and diamond-like carbon (DLC) films by means of a pulsed C02 laser. Ablation of fullerene material does not yield fullerite films, but results in amorphous pregraphitic carbon structures. At very low laser flux structural transformations are observed with increasing exposure time. These thermal effects cannot completely decompose the fullerenes without increase of the laser power density. Thermal evaporation is a suitable method to deposite fullerite fllms of high quality, thus epitaxial fullerite films are grown on mica. Sandwich C60/DLC structures are produced by laser deposition which show a sharp interface as can be deduced from the superposition of the characteristic Raman spectra of the fullerite and the DLC.}, language = {en} } @misc{FranckeRohrbeckRudolphetal.1998, author = {Francke, Klaus-Peter and Rohrbeck, Wolfgang and Rudolph, Rolf and Volkmann, Hans}, title = {1 kW Pulse Corona Reactor for Voc Destruction}, series = {Wissenschaftliche Beitr{\"a}ge 2/1998}, volume = {4}, journal = {Wissenschaftliche Beitr{\"a}ge 2/1998}, number = {2}, issn = {0949-8214}, doi = {10.15771/0949-8214_1998_2_9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-7546}, pages = {48 -- 50}, year = {1998}, abstract = {A I kW pulse corona reactor has been developed capable of treating gas flows up to 100 m3/h. The discharge efficiency reaches 80 \% in air and nearly 100 \% in nitrogen flows. The efficiency of radical production has been proofed by ozone synthesis as weil as by NO to N2 conversion.}, language = {en} } @misc{BeyerHarendtRolleetal.2000, author = {Beyer, Harald and Harendt, Andreas and Rolle, Siegfried and Ross, Werner and Volkmann, Hans}, title = {TE-CO2-Laser mit variabler Impulsdauer}, series = {Wissenschaftliche Beitr{\"a}ge 2/2000}, volume = {5}, journal = {Wissenschaftliche Beitr{\"a}ge 2/2000}, number = {2}, issn = {0949-8214}, doi = {10.15771/0949-8214_2000_2_2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-7006}, pages = {13 -- 16}, year = {2000}, abstract = {Laserbearbeitungsverfahren wie Pr{\"a}zisionschneiden und Bohren erfordern den Einsatz von Laserimpulsen mit angepasster Impulsleistung (10 kW) und Impulsdauer (10 μs bis zu einigen 100 μs). Transversal elektrisch (TE) angeregte Impuls-CO2 -Laser werden bei Gasdr{\"u}cken bis zu einigen 100 kPa betrieben. In diesem Bereich begrenzen jedoch einsetzende Plasmainstabilit{\"a}ten die m{\"o}gliche elektrische Anregungsdauer f{\"u}r ein homogenes nichtthermisches Entladungsplasma auf einige 100 ns [1]. Eine Verl{\"a}ngerung der Laserimpulsdauer ist durch Ver{\"a}nderung der Energietransportzeit im Lasermedium m{\"o}glich. In [2,3] wurde dies durch eine Herabsetzung des CO2 -Anteils im Gasgemisch sowie durch Herabsetzung des Gasdrucks erreicht. Mit der zus{\"a}tzlichen Verminderung des Heliumanteils [4] kann die Laserimpulsdauer bis zu 1000 μs ausgedehnt werden.}, language = {de} } @misc{BeyerPurschSchumacher2000, author = {Beyer, Harald and Pursch, Heinz and Schumacher, Andreas}, title = {Untersuchung des spektralen Einkoppelverhaltens von Lichtwellenleitersensoren}, series = {Wissenschaftliche Beitr{\"a}ge 2/2000}, volume = {5}, journal = {Wissenschaftliche Beitr{\"a}ge 2/2000}, number = {2}, issn = {0949-8214}, doi = {10.15771/0949-8214_2000_2_3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-7018}, pages = {17 -- 20}, year = {2000}, abstract = {In Schaltanlagen des Niederspannungsnetzes k{\"o}nnen St{\"o}rlichtb{\"o}gen zu erheblichen Sch{\"a}den f{\"u}hren. Die Ursache der Lichtb{\"o}gen ist vielf{\"a}ltig und reicht von {\"U}berschl{\"a}gen an Isolationsstrecken {\"u}ber Blitzeinschl{\"a}ge in das Netz bis zu Kurzschl{\"u}ssen, die bei Wartungs- oder Montagearbeiten verursacht werden k{\"o}nnen. Die Wirkungen von St{\"o}rlichtb{\"o}gen sind erheblich und k{\"o}nnen die Zerst{\"o}rung der Schaltanlage zur Folge haben. Die Kl{\"o}ckner-Moeller GmbH hat ein St{\"o}rlichtbogenschutzsystem (ARCON) entwickelt, das in die Schaltanlagen integriert wird. Da das Auftreten der St{\"o}rlichtb{\"o}gen nicht vorhersehbar ist, wird die gesamte Schaltanlage von Sensoren auf der Basis von Lichtwellenleitern {\"u}berwacht. F{\"u}r diesen Einsatzzweck sind die Sensoren so konzipiert, dass das Licht des Bogens nicht {\"u}ber die Stirnfl{\"a}che des Lichtleiters, sondern seitlich {\"u}ber den Mantel in den Kern eingekoppelt wird. Die Leuchterscheinungen jedes sich bildenden Lichtbogens k{\"o}nnen von dem Sensor erfasst und an einen Detektor weitergeleitet werden, dessen Signal die Schutzmaßnahmen einleitet. Dadurch kann der Strom noch w{\"a}hrend der ersten Halbwelle abgeschaltet und der Schaden begrenzt werden.}, language = {de} } @misc{SchmadlWittl2002, author = {Schmadl, Josef and Wittl, Romel}, title = {Experimentelle Untersuchung des W{\"a}rme{\"u}bergangs beim Sieden bin{\"a}rer Stoffgemische aus Aceton und Ethanol}, series = {Wissenschaftliche Beitr{\"a}ge 2002}, volume = {7}, journal = {Wissenschaftliche Beitr{\"a}ge 2002}, issn = {0949-8214}, doi = {10.15771/0949-8214_2002_10}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-6915}, pages = {59 -- 65}, year = {2002}, abstract = {Das Sieden und besonders das in dieser Arbeit ausschließlich behandelte vollausgebildete Blasensieden ist immer dann die bevorzugte Form der W{\"a}rme{\"u}bertragung an Fl{\"u}ssigkeiten, wenn hohe W{\"a}rmestr{\"o}me pro Heizfl{\"a}cheneinheit und pro K Heizwand{\"u}berhitzung {\"u}bertragen werden sollen. In vielen F{\"a}llen werden dabei nicht reine Stoffe, sondern Stoffgemische eingesetzt, z. B. bei der K{\"u}hlung von Chemiereaktoren oder bei der thermischen Trennung von Stoffgemischen (Destillation, Rektifikation und Eindampfung zwecks Kristallisation). Dabei ist zu ber{\"u}cksichtigen, dass der W{\"a}rme{\"u}bergangskoeffizient beim Blasensieden von Gemischen wegen des kombinierten W{\"a}rme- und Stoff{\"u}bergangs in der Regel kleiner als bei reinen Stoffen ist. Besonders bei hohen W{\"a}rmestromdichten, hohen Dr{\"u}cken und hohen relativen Fl{\"u}chtigkeiten der beteiligten Stoffkomponenten kann dieser „Gemischeffekt" den W{\"a}rme{\"u}bergangskoeffizienten um Faktor 10 und mehr herabsetzen, was in der Apparateauslegung ber{\"u}cksichtigt werden muss.}, language = {de} } @misc{SchmadlWittl2002, author = {Schmadl, Josef and Wittl, Romel}, title = {Korrelation der Konzentrations- und Druckabh{\"a}ngigkeit des W{\"a}rme{\"u}bergangskoeffizienten beim Sieden von bin{\"a}ren Stoffgemischen aus Aceton und Ethanol}, series = {Wissenschaftliche Beitr{\"a}ge 2002}, volume = {7}, journal = {Wissenschaftliche Beitr{\"a}ge 2002}, issn = {0949-8214}, doi = {10.15771/0949-8214_2002_11}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-6927}, pages = {66 -- 70}, year = {2002}, abstract = {Bislang gibt es keine einheitliche Theorie, um den W{\"a}rme{\"u}bergang beim Blasensieden in freier Konvektion f{\"u}r bin{\"a}re Gemische ohne experimentelle Daten und mit ausreichender Genauigkeit vorauszuberechnen. In der Literatur gibt es jedoch zahlreiche Korrelationsgleichungen bzw. Modelle f{\"u}r die praktische Berechnung des W{\"a}rme{\"u}bergangskoeffizienten (W{\"U}K). Diese Modelle oder Gleichungen sind empirische oder halbempirische Ans{\"a}tze, die nur auf spezielle Stoffpaare anwendbar oder auf niedrige Siededr{\"u}cke beschr{\"a}nkt sind oder nicht alle Einflussparameter enthalten.}, language = {de} } @article{VandenhoutenWendlandt2015, author = {Vandenhouten, Ralf and Wendlandt, Ole}, title = {High-precision Optical Position Measurement in Indoor Environments}, series = {Optik \& Photonik}, volume = {10}, journal = {Optik \& Photonik}, number = {3}, issn = {1863-1460}, doi = {10.1002/opph.201500022}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-9305}, pages = {24 -- 27}, year = {2015}, abstract = {Indoor localization is still a challenge today. Conventional methods based on satellite navigation, like GPS, can only be used outdoors. On the other hand, radio signal architectures, like WiFi or NFC, require high cost infrastructure to be installed inside the building. In collaboration with Ixellence GmbH, the research group for telematics of the University of Applied Science Wildau is developing a new inexpensive solution based on the camera of a mobile device. This approach only requires the availability of multiple identifiable landmarks that can be installed cost-efficiently in an indoor environment. Our investigations show that this method is very accurate and can produce repeatable, robust results.}, language = {en} } @inproceedings{BauerHeinrichFursenkoetal.2017, author = {Bauer, Joachim and Heinrich, Friedhelm and Fursenko, Oksana and Marschmeyer, Steffen and Bluemich, Adrian and Pulwer, Silvio and Steglich, Patrick and Villringer, Claus and Mai, Andreas and Schrader, Sigurd}, title = {Very high aspect ratio through silicon via reflectometry}, series = {Proceedings of SPIE}, booktitle = {Proceedings of SPIE}, issn = {1996-756X}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13758}, year = {2017}, abstract = {Through Silicon Via (TSV) technology is a key feature of new 3D integration of circuits by creation of interconnections using vias, which go through the silicon wafer. Typically, the highly-selective Bosch Si etch process, characterized by a high etch rate and high aspect ratio and forming of scallops on the sidewalls is used. As presented in this paper, we have developed an experimental setup and a respective evaluation algorithm for the control and monitoring of very high aspect ratio TSV profiles by spectroscopic reflectometry. For this purpose square via arrays with lateral dimension from 3 to 10 μm were fabricated by a Bosch etch process and analyzed by our setup. By exploiting interference and diffraction effects of waves reflected from the top and bottom surfaces as well as from the side walls of the TSV patterns, the measurements provided etch depths, CD values and scallop periods. The results were compared with data obtained by a commercial wafer metrology tool. Aspect ratios of up to 35:1 were safely evaluable by our setup.}, language = {en} } @inproceedings{VillringerGilaniZhangetal.2019, author = {Villringer, Claus and Gilani, Taravat Saeb and Zhang, Edward and Pulwer, Silvio and Steglich, Patrick and Schrader, Sigurd and Laufer, Jan}, title = {Development of tuneable Fabry-P{\´e}rot sensors for parallelised photoacoustic signal acquisition}, series = {Proc. SPIE 10878, Photons Plus Ultrasound: Imaging and Sensing 2019, 108780M (8 March 2019)}, booktitle = {Proc. SPIE 10878, Photons Plus Ultrasound: Imaging and Sensing 2019, 108780M (8 March 2019)}, issn = {1996-756X}, doi = {10.1117/12.2509437}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13769}, year = {2019}, abstract = {Fabry-P{\´e}rot (FP) sensors have enabled high resolution 3D photoacoustic (PA) imaging in backward mode. However, raster-scanning of the interrogation laser beam across the sensor can result in slow 3D image acquisition. To overcome this limitation, parallelized PA signal acquisition can be used for which FP sensors with uniform optical thickness are required. In this work, the optical thickness is tuned a) irreversibly through the use of a photopolymer host matrix and b) actively using embedded electro-optic (EO) chromophores. Polymer spacers (5 μm) were deposited using spin coating and sandwiched between two dielectric mirrors and transparent ITO electrodes. The employed polymer guest-host system consists of an EO chromophore (2-methyl-4-nitroaniline) and poly(vinyl cinnamate). EO tuneability was induced using contact poling and a tuneability of 68 pm was demonstrated. The optical thickness was homogenised by raster scanning a UV beam whilst varying the exposure time across a 4 mm2 detection aperture.}, language = {en} } @inproceedings{ChepurnaGrebinykPetrushkoetal.2019, author = {Chepurna, Oksana and Grebinyk, Anna and Petrushko, Yulia and Prylutska, Svitlana and Grebinyk, Sergii and Yashchuk, Valeriy and Matyshevska, Olga and Ritter, Uwe and Dandekar, Thomas and Frohme, Marcus and Qu, Junle and Ohulchanskyy, Tymish Y.}, title = {LED-based portable light source for photodynamic therapy}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-14778}, year = {2019}, abstract = {Photodynamic therapy (PDT) employs light activation of tissue-localized photosensitizer in an oxygen-dependent process which initiates oxidative stress, inflammation, and cell death. Laser systems, which are mostly used in PDT as light sources can be costly and oversized. light-emitting diodes (LEDs) equipment has a high potential to simplify technical part of phototriggered therapies and to reduce its costs. We develop the LED-based system that includes the control and irradiation units. The system provides the same power density at any irradiation point. Among the advantages of the device is a possibility to change the irradiation area and tune the irradiation dose. PDT experiments with cancer cells in vitro treated with two different photosensitizers demonstrated a possibility to use the developed LED-based system as a low-cost light source in PDT.}, language = {en} } @inproceedings{PulwerFiebelkornZeschetal.2019, author = {Pulwer, Silvio and Fiebelkorn, Richard and Zesch, Christoph and Steglich, Patrick and Villringer, Claus and Villasmunta, Francesco and Gedat, Egbert and Handrich, Jan and Schrader, Sigurd and Vandenhouten, Ralf}, title = {Endoscopic orientation by multimodal data fusion}, series = {Proc. SPIE 10931, MOEMS and Miniaturized Systems XVIII}, booktitle = {Proc. SPIE 10931, MOEMS and Miniaturized Systems XVIII}, issn = {1996-756X}, doi = {10.1117/12.2508470}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-11420}, year = {2019}, abstract = {To improve the feasibility of endoscopic inspection processes we developed a system that provides online information about position, orientation and viewing direction of endoscopes, to support the analysis of endoscopic images and to ease the operational handling of the equipment. The setup is based on an industrial endoscope consisting of a camera, various MEMS and multimodal data fusion. The software contains algorithms for feature and geometric structure recognition as well as Kalman filters. To track the distal end of the endoscope and to generate 3D point cloud data in real time the optical and photometrical characteristics of the system are registered and the movement of the endoscope is reconstructed by using image processing techniques.}, language = {en} } @article{BondarenkoHuelsemannMaietal.2021, author = {Bondarenko, Siegfried and H{\"u}lsemann, Marcel and Mai, Andreas and Steglich, Patrick}, title = {Fiber-to-chip light coupling using a graded-index lensed fiber collimator}, series = {Optical Engineering}, volume = {60}, journal = {Optical Engineering}, number = {1}, publisher = {SPIE}, issn = {1560-2303}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13749}, year = {2021}, abstract = {Fiber-to-chip light coupling using a graded-index (GRIN) fiber collimator is investigated. Our experiments with grating couplers and strip waveguides fabricated in a photonic integrated circuit technology reveal that the peak coupling efficiency of a GRIN fiber collimator is 7.8 dB lower than that of a single-mode fiber. However, the 3-dB alignment tolerance is improved by a factor of about 5.7 giving rise to pluggable sensor solutions. This work opens a path toward a cost-effective and portable sensor platform based on pluggable photonic biosensors using GRIN fiber collimators.}, language = {en} } @article{KagelJacobsBieretal.2019, author = {Kagel, Heike and Jacobs, Hannes and Bier, Frank Fabian and Gl{\"o}kler, J{\"o}rn and Frohme, Marcus}, title = {A Novel Microtiter Plate Format High Power Open Source LED Array}, series = {Photonics}, volume = {6}, journal = {Photonics}, number = {1}, issn = {2304-6732}, doi = {10.3390/photonics6010017}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-11307}, year = {2019}, abstract = {Many photochemical or photobiological applications require the use of high power ultraviolet light sources, such as high-pressure mercury arc lamps. In addition, many photo-induced chemical, biochemical and biological applications require either a combinatorial setting or a parallel assay of multiple samples under the same environmental conditions to ensure reproducibility. To achieve this, alternative, controllable light sources, such as ultraviolet light emitting diodes (UV LEDs) with high power and spatial control are required. Preferably, LEDs are arranged in a suitable standardized 96-well microtiter plate format. We designed such an array and established the methods required for heat management and enabling stable, controllable illumination over time.}, language = {en} } @article{JurkovičovaBenLtaiefRoosetal.2024, author = {Jurkovičov{\´a}, Lucie and Ben Ltaief, Ltaief and Roos, Andreas Hult and Hort, Ondřej and Finke, Ondřej and Albrecht, Martin and Hoque, Ziaul and Klimešov{\´a}, Eva and Sundaralingam, Akgash and Antipenkov, Roman and Grenfell, Annika and Špaček, Alexandr and Szuba, Wojciech and Krikunova, Maria and Mudrich, Marcel and Nejdl, Jaroslav and Andreasson, Jakob}, title = {Bright continuously tunable vacuum ultraviolet source for ultrafast spectroscopy}, series = {Communications Physics}, volume = {7}, journal = {Communications Physics}, publisher = {Nature Publishing Group}, issn = {2399-3650}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18462}, year = {2024}, abstract = {Ultrafast 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.}, language = {en} } @article{MedinaLagdsmandBenLtaiefetal.2023, author = {Medina, Cristian and L{\ae}gdsmand, Asbj{\o}rn {\O}rnemark and Ben Ltaief, Ltaief and Hoque, Ziaul and Roos, Andreas Hult and Jurkovičov{\´a}, Lucie and Hort, Ondřej and Finke, Ondřej and Albrecht, Martin and Nejdl, Jaroslav and Stienkemeier, Frank and Andreasson, Jakob and Klimešov{\´a}, Eva and Krikunova, Maria and Heidenreich, Andreas and Mudrich, Marcel}, title = {Long-lasting XUV activation of helium nanodroplets for avalanche ionization}, series = {New Journal of Physics}, volume = {25}, journal = {New Journal of Physics}, publisher = {Institute of Physics (IOP)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-17701}, year = {2023}, abstract = {We study the dynamics of avalanche ionization of pure helium nanodroplets activated by a weak extreme-ultraviolet (XUV) pulse and driven by an intense near-infrared (NIR) pulse. In addition to a transient enhancement of ignition of a nanoplasma at short delay times \${\sim}200\$ fs, long-term activation of the nanodroplets lasting up to a few nanoseconds is observed. Molecular dynamics simulations suggest that the short-term activation is caused by the injection of seed electrons into the droplets by XUV photoemission. Long-term activation appears due to electrons remaining loosely bound to photoions which form stable 'snowball' structures in the droplets. Thus, we show that XUV irradiation can induce long-lasting changes of the strong-field optical properties of nanoparticles, potentially opening new routes to controlling avalanche-ionization phenomena in nanostructures and condensed-phase systems.}, language = {en} } @article{SmekhovaSzyjkaLaTorreetal.2024, author = {Smekhova, Alevtina and Szyjka, Thomas and La Torre, Enrico and Ollefs, Katharina and Eggert, Benedikt and Coester, Birte and Wilhelm, Fabrice and Bali, Rantej and Lindner, J{\"u}rgen and Rogalev, A. and T{\"o}bbens, Daniel Maria and Weschke, Eugen and Luo, Chen and Chen, Kai and Radu, Florin and Schmitz-Antoniak, Carolin and Wende, Heiko}, title = {Irradiation-induced enhancement of Fe and Al magnetic polarizations in Fe60Al40 films}, series = {New Journal of Physics}, volume = {26}, journal = {New Journal of Physics}, publisher = {Institute of Physics Publishing (IOP)}, issn = {1367-2630}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18381}, year = {2024}, abstract = {The 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.}, language = {en} } @inproceedings{KupperMuehligJakobeschky2024, author = {Kupper, Stefan and M{\"u}hlig, Verena and Jakobeschky, Laura}, title = {AD3D - Eine automatisierte Toolchain f{\"u}r das 3D-Drucken}, series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: Praktische L{\"o}sungen f{\"u}r die industrielle Automation}, booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: Praktische L{\"o}sungen f{\"u}r die industrielle Automation}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and St{\"o}cker, Christian}, publisher = {Hochschule f{\"u}r Technik, Wirtschaft und Kultur}, address = {Leipzig}, isbn = {978-3-910103-02-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18553}, pages = {259 -- 263}, year = {2024}, abstract = {Der technische Fortschritt hat dazu gef{\"u}hrt, dass die Kosten f{\"u}r das automatisierte Drucken von Emblemen, Anh{\"a}ngern 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 f{\"u}r das automatische 3D-Drucken eines Logos pr{\"a}sentiert, welches als Pixelgrafik vorliegt. Die vorgeschlagene Prozesskette erzeugt hierbei final den G-code zum Drucken. Dabei sind seitens des Users wenige Eingaben erforderlich.}, language = {de} } @article{LuxSiemrothSgarlataetal.2015, author = {Lux, Helge and Siemroth, Peter and Sgarlata, Anna and Prosposito, Paolo and Schubert, Markus Andreas and Casalboni, Mauro and Schrader, Sigurd}, title = {Synthesis of graphene-like transparent conductive films on dielectric substrates using a modified filtered vacuum arc system}, series = {Journal of Applied Physics}, volume = {117}, journal = {Journal of Applied Physics}, number = {19}, issn = {1089-7550}, doi = {10.1063/1.4921448}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-9738}, year = {2015}, abstract = {Here, we present a reliable process to deposit transparent conductive films on silicon oxide, quartz, and sapphire using a solid carbon source. This layer consists of partially ordered graphene flakes with a lateral dimension of about 5 nm. The process does not require any catalytic metal and exploits a high current arc evaporation (Φ-HCA) to homogeneously deposit a layer of carbon on heated substrates. A gas atmosphere consisting of Argon or Argon/Hydrogen blend acting as a buffer influences the morphology of the growing film. scanning tunneling microscopy, transmission electron microscopy, and Raman spectra were used for a thorough characterization of the samples in order to optimize the growth parameters. The best carbon layers have a surface resistance of 5.7 × 103 Ω◻ whereas the optical transparency of the coatings is 88\% with an excellent homogeneity over areas of several cm2. Such results are compatible with most semiconductor fabrication processes and make this method very promising for various industrial applications.}, language = {en} } @article{SteglichMaiVillringeretal.2018, author = {Steglich, Patrick and Mai, Christian and Villringer, Claus and Pulwer, Silvio and Casalboni, Mauro and Schrader, Sigurd and Mai, Andreas}, title = {Quadratic electro-optic effect in silicon-organic hybrid slot-waveguides}, series = {Optics Letters}, volume = {43}, journal = {Optics Letters}, number = {15}, issn = {1539-4794}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-12148}, year = {2018}, abstract = {This Letter reports on the quadratic electro-optic effect of polymers, observed in a silicon slot-waveguide at low voltages. We demonstrate that in narrow slots, the electro-optic response with respect to refractive index change is strong enough for on-chip wavelength tuning and intensity modulation using voltages as low as 1 V. A silicon slot-waveguide embedded by a nonlinear optical polymer, consisting of the dye Disperse Red 1 in poly(methyl methacrylate), serves as the phase shifter in a racetrack ring resonator. As deduced from the experimental data, the third-order susceptibility of the utilized electro-optic polymer is about 2·10-19 m2/V2. The demonstrated low-voltage operation and inherently thermal stability show the potential for silicon-organic hybrid devices using the quadratic electro-optic effect.}, language = {en} }