TY - JOUR A1 - Lux, Helge A1 - Edling, Matthias A1 - Lucci, Massimiliano A1 - Kitzmann, Julia A1 - Villringer, Claus A1 - Siemroth, Peter A1 - De Matteis, Fabio A1 - Schrader, Sigurd T1 - The Role of Substrate Temperature and Magnetic Filtering for DLC by Cathodic Arc Evaporation JF - Coatings N2 - Diamond-like carbon (DLC) films were deposited using two different types of high current arc evaporation. The first process used a magnetic particle filter to remove droplets from the plasma. For the second process, the samples were put into a metallic cage which was placed directly above the plasma source. For both processes, we varied the substrate temperature from 21 to 350 °C in order to investigate the temperature effect. The samples were characterized using SEM, AFM, XPS, Raman Spectroscopy, Ellipsometry, Photometry, and Nano Indentation in order to compare both methods of deposition and provide a careful characterization of such DLC films. We found that the sp3 content and the hardness can be precisely adjusted by changing the substrate temperature. Furthermore, in the case of unfiltered deposition, the optical constants can be shifted in the direction of higher absorbance in order to produce black and hard carbon coatings. KW - DLC KW - ta-C KW - arc evaporation KW - substrate temperature KW - hardness KW - optical constant KW - ellipsometry Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-12295 SN - 2079-6412 VL - 9 IS - 5 SP - 345 ER - TY - JOUR A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Dietzel, Birgit A1 - Mai, Christian A1 - Schrader, Sigurd A1 - Casalboni, Mauro A1 - Mai, Andreas T1 - On-Chip Dispersion Measurement of the Quadratic Electro-Optic Effect in Nonlinear Optical Polymers Using a Photonic Integrated Circuit Technology JF - IEEE Photonics Journal N2 - A novel method to determine the dispersion of the quadratic electro-optic effect in nonlinear optical materials by using a silicon-on-insulator microring resonator is presented. The microring consists of a silicon slot waveguide enabling large dc electric field strength at low applied voltages. The dispersion of third-order hyperpolarizability of a linear conjugated dye is approximated by using a two-level model for the off-resonant spectral region. As an example, the dispersion of the resonance wavelength of the resonator filled with a dye doped polymer was measured in dependence of the applied dc voltage. The polymer was poly (methylmethacrylate) doped with 5 wt% disperse red 1 (DR1), and the measurements have been carried out at the telecommunication wavelength band around 1550 nm (optical C-band). The described measurements represent a new technique to determine the dispersion of the third-order susceptibility and molecular hyperpolarizability of the material filled into the slot of the ring-resonator. KW - electro-optical device KW - nonlinear optics KW - integrated optics KW - integrated optics material KW - optical material KW - integrated optics device KW - polymer active device Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-12307 SN - 1943-0655 VL - 11 IS - 3 ER - TY - JOUR A1 - Lux, Helge A1 - Edling, Matthias A1 - Siemroth, Peter A1 - Schrader, Sigurd T1 - Fast and Cost-Effective Synthesis of High-Quality Graphene on Copper Foils Using High-Current Arc Evaporation JF - Materials N2 - In this paper, we present an innovative and ultra-fast process for the deposition of high-quality graphene on different metal foils and thin metal films. The graphene layer can be homogeneously deposited in only 30 s process time. Due to the weak adhesion to the substrate material, the monolayer graphene is easy to transfer using the established processes. For the production, we use magnetic filtered high-current arc evaporation (Φ-HCA) with a solid, graphitic carbon source. This ultra-fast growth process can pave the way towards a cost-effective graphene synthesis for the mass production e.g., in a roll-to-roll process, avoiding time consuming established processes. KW - graphene KW - PVD KW - arc evaporation KW - copper KW - transfer KW - Φ-HCA Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-10359 SN - 1996-1944 VL - 11 IS - 5 SP - 1 EP - 10 ER - TY - JOUR A1 - Grytsenko, Kostyantyn A1 - Ksianzou, Viachaslau A1 - Kolomzarov, Yurii A1 - Lytvyn, Peter A1 - Dietzel, Birgit A1 - Schrader, Sigurd T1 - Fluoropolymer Film Formation by Electron Activated Vacuum Deposition JF - Surfaces N2 - Polytetrafluoroethylene (PTFE), polyhexafluoropropylene (PHFP) and polychlorotrifluoroethylene (PCTFE) were heated to their decomposition temperature in a high vacuum. The emitted fragments passed an electron cloud, condensed on a substrate and formed fluoropolymer film. Growth rate of PTFE and PHFP films increased up to a factor five in the presence of the electron cloud. Mass spectrometry revealed changes in the mass spectra of fragments generated by thermal decomposition only and formed under electron activation. The observed changes were different for each fluoropolymer. Infrared spectroscopy (IRS) showed that the structure of the films was close to the structure of the bulk polymers. Atomic force microscopy (AFM) has revealed different morphologies of PTFE, PHFP and PCTFE films, suggesting a Volmer–Weber growth mechanism for PTFE and PHFP but a Frank-van der Merwe one for PCTFE. All films were smooth at nanoscale and transparent from ultraviolet to near-infrared region. Additional radio frequency (RF) plasma ignited in the emitted fragments at a low pressure increased mechanical characteristics of the films without losing their optical transparency and smoothness. KW - fluoropolymer thin film KW - vacuum deposition KW - polymerization KW - plasma KW - surface Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13786 SN - 2571-9637 VL - 4 IS - 1 SP - 66 EP - 80 PB - MDPI ER - TY - GEN A1 - Beyer, Harald A1 - Hofmann, Mandy A1 - Trutz, Sebastian A1 - Lux, Helge A1 - Stissel, Sven A1 - Mehr, Wolfgang A1 - Schrader, Sigurd A1 - Siemroth, Peter T1 - Großflächige Abscheidung von Graphen - Ein wichtiger Schritt für neuartige Bauelemente T2 - Wissenschaftliche Beiträge 2013 N2 - Das wachsende Interesse an Graphen beruht auf seiner unverwechselbaren Bandstruktur und seinen damit zusammenhängenden herausragenden physikalischen Eigenschaften. Es wird daher weltweit nach einem Verfahren gesucht, Graphen großflächig und mit hoher Qualität abzuscheiden. In einer an der TH Wildau [FH] speziell für diese Aufgabe konzipierten Reaktionskammer wurde die Herstellung mittels chemischer Gasphasenabscheidung auf katalytischen Metalloberflächen für verschiedene Parameter studiert und deren Verträglichkeit mit der CMOS -Technologie untersucht. Die ersten Tests erfolgten auf Nickel, da hier eine im Volumen stattfindende katalytische Reaktion einsetzt. In weiteren Schritten fiel die Wahl auf Kupfer, da hier die Reaktion an der Oberfläche stattfindet und daher ein stabilerer Prozess realisiert werden konnte. Die Qualitätsprüfung der erzeugten Schichten erfolgte mittels Ramanspektrometrie. Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-3169 SN - 0949-8214 VL - 17 SP - 154 EP - 159 ER - TY - JOUR A1 - Dimitriev, O. P. A1 - Grytsenko, Kostyantyn A1 - Tolmachev, O. I. A1 - Slominskii, Yu L. A1 - Kudinova, M. A. A1 - Schrader, Sigurd T1 - Effect of Concentration on Isomerization of Rhodanine Derivatives of Merocyanine Dyes in Polar Solvents JF - Advances in Physical Chemistry N2 - Rhodanine derivatives of merocyanine dyes with residues of 1,3,3-trimethyl-3H-indole and 3-ethylbenzothiazoline have been found to possess two molecular forms in diluted solutions of polar solvents such as dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidinone. The first molecular form was observed to prevail at low concentrations of the dyes, normally up to 10−5 M. The second one prevails at higher concentrations and is displayed through a new band in the electronic absorption spectrum, which is red-shifted with respect to the absorption band of the first form. No similar effect was found for these dyes by use of nonpolar solvents or upon alkyl-substitution of the molecules at nitrogen atom in the rhodanine moiety. We assign the above two forms to different molecular isomers and the analogous spectral changes were shown to take place by light or heat influence which correspond to a typical isomerization effect for the related merocyanine dyes. It is discussed that the isomer transformation is facilitated by the increased mobility of the proton bonded to the nitrogen atom of the rhodanine moiety in the polar environment and the increased amount of dye-dye collisions. Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-5931 SN - 1687-7993 VL - 2014 ER - TY - CHAP A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Dümecke, Silvio A1 - Padilla-Michel, Yazmin A1 - Casalboni, Mauro A1 - Schrader, Sigurd T1 - Silicon-On-Insulator Slot-Waveguide Design Trade-Offs T2 - Proceedings of the 3rd International Conference on Photonics, Optics and Laser Technology : vol. 2 N2 - Silicon-on-insulator slot-waveguide structures are designed and analysed numerically. We present our theoretical investigation of field confinement factors and effective nonlinear areas for different waveguide structures in order to find optimized geometrical dimensions. It is shown that a slot-waveguide with a height of 220 nm, a slot width of 180 nm and a silicon rail width of 180 nm provides a five times higher field confinement in the cladding region compared to conventional strip-waveguides which explains the high sensitivity of slotwaveguide based label-free bio-sensors. KW - slot waveguide KW - silicon-organic hybrid technology KW - optical field confinement KW - effective nonlinear area Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-20104 SP - 47 EP - 52 PB - SciTePress CY - Setúbal ER - TY - CHAP A1 - Padilla-Michel, Yazmin A1 - Lucci, Massimiliano A1 - Casalboni, Mauro A1 - Steglich, Patrick A1 - Schrader, Sigurd ED - Ribeiro, Paulo A. T1 - Mechanical Characterisation of the Four Most Used Coating Materials for Optical Fibres T2 - Proceedings of the 3rd International Conference on Photonics, Optics and Laser Technology : vol. 1 N2 - Optical multimode fibres have a wide variety of applications ranging from industrial to medical use. Therefore, even if they are just used as waveguides or sensors, it is important to characterise the whole fingerprint, including the optical and mechanical properties of such fibres. Since the stiffness/elasticity of a material could influence the optical output of a fibre due to micro-bendings, in this paper we report the calculated Young’s Modulus of acrylate, fluorinated acrylate, polyimide and silicone, which are the four most used coating materials for such optical components. The results demonstrate that Young’s Modulus does have an impact on the attenuation of propagating light along the optical fibre. However, the refractive index of the coating materials still has a significant impact on the performance of optical fibres. KW - fibre optics KW - coating material KW - Young’s Modulus KW - nanoindentation KW - attenuation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-20063 SP - 96 EP - 102 PB - SciTePress CY - Setúbal ER - TY - JOUR A1 - Grytsenko, Kostyantyn A1 - Lozovski, Valeri A1 - Strilchuk, Galyna A1 - Schrader, Sigurd T1 - Evaluation of the Mechanism of the Gold Cluster Growth during Heating of the Composite Gold-Polytetrafluoroethylene Thin Film JF - Nanomaterials N2 - Nanocomposite films consisting of gold inclusions in the polytetrafluoroethylene (PTFE) matrix were obtained by thermal vacuum deposition. Annealing of the obtained films with different temperatures was used to measure varying of film morphologies. The dependence of optical properties of the films on their morphology was studied. It was established that absorption and profile of the nanocomposite film obtained by thermal vacuum deposition can be changed with annealing owing to the fact that different annealing temperatures lead to different average particle sizes. A method to calculate the optical properties of nanocomposite thin films with inclusions of different sizes was proposed. Thus, comparison of experimental optical spectra with the spectra obtained during the simulation enables estimating average sizes of inclusions. The calculations give the possibility of understanding morphological changes in the structures. KW - nanocomposite KW - gold KW - polytetrafluoroethylene KW - optical spectroscopy KW - microscopy KW - thin film Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-6387 SN - 2079-4991 VL - 2 IS - 4 SP - 366 EP - 378 ER - TY - JOUR A1 - Villringer, Claus A1 - Steglich, Patrick A1 - Pulwer, Silvio A1 - Schrader, Sigurd A1 - Laufer, Jan T1 - Electro-optical properties of doped polymers with high transparency in the visible wavelength range JF - Optical Materials Express N2 - The electro-optical (EO) properties of poly(methyl methacrylate) and the photopolymer poly(vinyl cinnamate) doped with varying concentrations of the EO chromophore 2-Methyl-4-nitroaniline were measured. The EO polymers were embedded in Fabry-Pérot etalons for the simultaneous determination of the Pockels and Kerr coefficients from measurements of the fringe shift induced by an external electric field. It was found that the host polymer has a significant impact on the EO performance and that the undoped host polymers exhibit a significant Pockels effect. Moreover, the Kerr effect provides a substantial contribution of 27% to the total change of the refractive index at relatively high electric field strengths of E = 91.2 MV m−1. KW - Bragg reflector KW - fiber optic coupler KW - refractive index KW - spatial light modulator KW - transparency KW - tunable filter Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15480 VL - 11 IS - 11 SP - 3801 EP - 3811 PB - Optica Publishing Group ER - TY - JOUR A1 - Bauer, Joachim A1 - Fursenko, Oksana A1 - Heinrich, Friedhelm A1 - Gutke, Marko A1 - Kornejew, Eckhart A1 - Brödel, Oliver A1 - Dietzel, Birgit A1 - Kaltenbach, Alexander A1 - Burkhardt, Martin A1 - Edling, Matthias A1 - Steglich, Patrick A1 - Herzog, Michael A1 - Schrader, Sigurd T1 - Determination of optical constants and scattering properties of transparent polymers for use in optoelectronics JF - Optical Materials Express N2 - Knowledge of optical constants, i.e. refractive index n and extinction coefficient k, and light scattering properties of optical polymers are required to optimize micro-optics for light-emitting diodes in terms of efficiency, color properties and light distribution. We present here a model-based diagnostic approach to determine the optical properties of polymers, which should be particularly useful in the development of plastics for optical applications. Optical constants and scattering coefficients were obtained from transmission and reflection measurements in a wavelength range from UV to NIR taking into account scattering effects due to rough surfaces and volume inhomogeneity. Based on the models for the dielectric function, the molecular optical transition energies Eg, critical point energies, Urbach energies and exciton transition energies were determined. Rayleigh and Mie scattering model and van de Hulst's anomalous diffraction theory were applied to characterize scattering due to volume inhomogeneities. Scalar diffraction theory was applied to account for surface roughness scattering. Atomic force microscopy with nanomechanical characterization was used to characterize domains in size and shape and to assign optical scattering to a suitable morphological model. The combined optical and mechanical characterization help to improve the qualification of new polymer materials for optical applications. KW - diffraction theory KW - light property KW - optical constant KW - optical material KW - optical property KW - scattering theory Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15666 VL - 12 IS - 1 SP - 204 EP - 224 PB - Optica Publishing Group ER - TY - JOUR A1 - Sopinskyy, Mykola A1 - Grytsenko, Kostyantyn A1 - Villringer, Claus A1 - Kolomzarov, Yurii A1 - Schrader, Sigurd T1 - Determination of scattering and Urbach absorption contributions to the light extinction in PTFE films by using graphical representation technique and numerical solution of the inverse problem JF - Semiconductor Physics, Quantum Electronics & Optoelectronics N2 - Ellipsometrically obtained spectral dependences of ordinary αxy and extra-ordinary αz extinction/attenuation coefficients within the spectral range λ = 300…980 nm of uniaxially anisotropic polytetrafluoroethylene (PTFE) films were analyzed. We considered the capabilities and specific features of the graphical representation technique for determining the contribution of Rayleigh scattering and Urbach absorption to light attenuation in the spectral range beyond fundamental absorption. It has been shown that the graphical approach enables to estimate these contributions qualitatively, semi-quantitatively or quantitatively, depending on the situation. The conclusions made using the analysis of graphical representation are confirmed by numerical solution of the inverse problem via simulation of the αxy (λ), αz (λ) experimental dependences within the framework of a best-fit procedure. Being based on both of these approaches, we have ascertained that, in the as-prepared PTFE films, the so-called anomalous light scattering (ALS) with the spectral dependence of scattering coefficient αs ≈ as λ–p (p > 4) takes place. Transformation of scattering from ALS to the Rayleigh one with p ≈ 4 due to annealing is accompanied by an increase of Urbach (subband) absorption. Both of these factors cause narrowing the dynamic range of extinction coefficient values. Both scattering and absorption coefficients are higher for the component of light polarized along the normal to the substrate as compared to the component polarized in parallel to it. The relationship between observed behavior of the scattering and absorption coefficients and the film structure has been discussed. KW - Rayleigh scattering KW - Urbach tail KW - absorption coefficient KW - scattering coefficient KW - graphical method KW - ellipsometry KW - polytetrafluoroethylene Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-18035 SN - 1605-6582 VL - 26 IS - 3 SP - 303 EP - 314 PB - National Academy of Sciences of Ukraine. Institute for Semiconductor Physics CY - Kyiv ER - TY - JOUR A1 - Grytsenko, Kostyantyn A1 - Kolomzarov, Yurii A1 - Lytvyn, Peter A1 - Kondratenko, Olga A1 - Sopinskyy, Mykola A1 - Lebedyeva, Iryna A1 - Niemczyk, Agata A1 - Baranowska, Jolanta A1 - Moszyński, Dariusz A1 - Villringer, Claus A1 - Schrader, Sigurd T1 - Optical and Mechanical Properties of Thin PTFE Films, Deposited from a Gas Phase JF - Macromolecular Materials and Engineering N2 - Thin polytetrafluoroethylene (PTFE) films are produced by deposition from a gas phase by two methods: electron-enhanced vacuum deposition (EVD) and EVD + low-temperature plasma (LTP). Structure, morphology, and composition of the films are studied by IR spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. They are close to the structure of bulk PTFE. The roughness of the films’ surface is changed with gas pressure and LTP power variations. Films are transparent from UV to near-infrared regions. Refractive and extinction indices and their anisotropy are measured by spectral ellipsometry. They are tuned by variations of deposition conditions. Hardness and Young modulus of the films are increased if EVD + low power LTP is used for film deposition. Use of EVD + LTP also increases thermal stability of the films. Contact angle of the films corresponds to the bulk PTFE. The PTFE molecules oriented are preferentially in perpendicular direction to the substrate surface. KW - deposition in vacuum KW - multiphase structure formation KW - optical property KW - plasma KW - polytetrafluoroethylene thin film Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-17587 VL - 308 IS - 6 PB - Wiley ER - TY - CHAP A1 - Steglich, Patrick A1 - Mai, Christian A1 - Stolarek, David A1 - Lischke, Stefan A1 - Kupijai, Sebastian A1 - Villringer, Claus A1 - Pulwer, Silvio A1 - Heinrich, Friedhelm A1 - Bauer, Joachim A1 - Meister, Stefan A1 - Knoll, Dieter A1 - Casalboni, Mauro A1 - Schrader, Sigurd T1 - Partially slotted silicon ring resonator covered with electro-optical polymer T2 - Proceedings of SPIE N2 - In this work, we present for the first time a partially slotted silicon ring resonator (PSRR) covered with an electro-optical polymer (Poly[(methyl methacrylate)-co-(Disperse Red 1 acrylate)]). The PSRR takes advantage of both a highly efficient vertical slot waveguide based phase shifter and a low loss strip waveguide in a single ring. The device is realized on 200 mm silicon-on-insulator wafers using 248 nm DUV lithography and covered with the electro-optic polymer in a post process. This silicon-organic hybrid ring resonator has a small footprint, high optical quality factor, and high DC device tunability. A quality factor of up to 105 and a DC device tunability of about 700 pm/V is experimentally demonstrated in the wavelength range of 1540 nm to 1590 nm. Further, we compare our results with state-of-the-art silicon-organic hybrid devices by determining the poling efficiency. It is demonstrated that the active PSRR is a promising candidate for efficient optical switches and tunable filters. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13771 SN - 1996-756X ER - TY - CHAP A1 - Padilla-Michel, Yazmin A1 - Pulwer, Silvio A1 - Saffari, Pouneh A1 - Ksianzou, Viachaslau A1 - Schrader, Sigurd T1 - On the origin and removal of interference patterns in coated multimode fibres N2 - In this study, we present the experimental investigations on interference patterns, such as those already reported in VIMOS-IFU, and up to now no appropriate explanation has been presented. These interference patterns are produced in multimode fibres coated with acrylate or polyimide, which is the preferred coating material for the fibres used in IFUs. Our experiments show that, under specific conditions, cladding modes interact with the coating and produce interference. Our results show that the conditions at which the fibre is held during data acquisition has an impact in the output spectrum. Altering the positioning conditions of the fibre leads to the changes into the interference pattern, therefore, fibres should be carefully manipulated in order to minimise this potential problem and improve the performance of these instruments. Finally we present a simple way of predicting and modelling this interference produced from the visible to the near infrared spectra. This model can be included in the data reduction pipeline in order to remove the interference patterns. These results should be of interest for the optimisation of the data reduction pipelines of instruments using optical fibres. Considering these results will benefit innovations and developments of high performance fibre systems. KW - instrumentation KW - multimode fibre KW - bending loss KW - fringing KW - interference KW - coating material KW - data reduction Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15295 SP - 1517 EP - 1527 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Pulwer, Silvio A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Bauer, Joachim A1 - Burger, Martin A1 - Franz, M. A1 - Grieshober, K. A1 - Wirth, F. A1 - Blondeau, J. A1 - Rautenberg, J. A1 - Mouti, S. A1 - Schrader, Sigurd T1 - Triangulation-based 3D surveying borescope N2 - In this work, a measurement concept based on triangulation was developed for borescopic 3D-surveying of surface defects. The integration of such measurement system into a borescope environment requires excellent space utilization. The triangulation angle, the projected pattern, the numerical apertures of the optical system, and the viewing angle were calculated using partial coherence imaging and geometric optical raytracing methods. Additionally, optical aberrations and defocus were considered by the integration of Zernike polynomial coefficients. The measurement system is able to measure objects with a size of 50 μm in all dimensions with an accuracy of ± 5 μm. To manage the issue of a low depth of field while using an optical high resolution system, a wavelength dependent aperture was integrated. Thereby, we are able to control depth of field and resolution of the optical system and can use the borescope in measurement mode with high resolution and low depth of field or in inspection mode with low resolution and higher depth of field. First measurements of a demonstrator system are in good agreement with our simulations. KW - borescope KW - 3D measurement KW - triangulation KW - lens design KW - calibration KW - defect Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15307 SP - 51 EP - 56 PB - SPIE ER - TY - CHAP A1 - Pulwer, Silvio A1 - Jahns, Daniel A1 - Villringer, Claus A1 - Schrader, Sigurd T1 - Dynamic pattern generation by singlemode fibers for endoscopic 3D measurement systems N2 - This work presents experimental and simulation results of a 3D measurement concept based on fiber-optic interference pattern generation. A demonstrator system which is able to adjust different optical and mechanical parameters is described. The results of parameter variation studies are discussed along with possible applications in the field of micro-optical 3D measurement systems like endoscopes. The experiments were prepared with different structures with various scattering properties. To implement that approach into a micro-optical 3D measurement system, the combination of distance variation between the fibers and a controlled phase shift introduced by a retarder can be used to design the system versatile. KW - endoscope KW - 3D measurement KW - phase shift KW - fiber Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15364 PB - SPIE ER - TY - CHAP A1 - Gilani, Taravat Saeb A1 - Villringer, Claus A1 - Zhang, Edward A1 - Gundlach, H. A1 - Buchmann, Jens A1 - Schrader, Sigurd A1 - Laufer, Jan T1 - Parallelised photoacoustic signal acquisition using a Fabry-Perot sensor and a camera-based interrogation scheme N2 - Tomographic photoacoustic (PA) images acquired using a Fabry-Perot (FP) based scanner offer high resolution and image fidelity but can result in long acquisition times due to the need for raster scanning. To reduce the acquisition times, a parallelised camera-based PA signal detection scheme is developed. The scheme is based on using a sCMOScamera and FPI sensors with high homogeneity of optical thickness. PA signals were acquired using the camera-based setup and the signal to noise ratio (SNR) was measured. A comparison of the SNR of PA signal detected using 1) a photodiode in a conventional raster scanning detection scheme and 2) a sCMOS camera in parallelised detection scheme is made. The results show that the parallelised interrogation scheme has the potential to provide high speed PA imaging. KW - photoacoustic imaging KW - parallelised signal acquisition KW - Fabry-Perot polymer film sensor Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15335 SP - 217 EP - 222 PB - SPIE ER - TY - CHAP A1 - Villringer, Claus A1 - Gilani, Taravat Saeb A1 - Zhang, Edward A1 - Pulwer, Silvio A1 - Steglich, Patrick A1 - Schrader, Sigurd A1 - Laufer, Jan T1 - Development of tuneable Fabry-Pérot sensors for parallelised photoacoustic signal acquisition T2 - Proc. SPIE 10878, Photons Plus Ultrasound: Imaging and Sensing 2019, 108780M (8 March 2019) N2 - Fabry-Pérot (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. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13769 SN - 1996-756X PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - JOUR A1 - Ksianzou, Viachaslau A1 - Velagapudi, R. K. A1 - Grimm, Bernd A1 - Schrader, Sigurd T1 - Polarization-dependent optical characterization of poly(phenylquinoxaline) thin films JF - Journal of Applied Physics N2 - Linear optical properties of two types of poly(phenylquinoxaline) (PPQ) are studied by multiwavelength prism coupling technique and optical absorption spectroscopy. Surface roughness measurements are done using atomic force microscopy. PPQs form smooth films of high optical quality having refractive indices above 1.7 in the visible and near infrared spectral ranges. Enhanced birefringence of Δn∼0.04Δn∼0.04 has been observed in both PPQ films prepared by spin coating. Sellmeier coefficients are derived for the wavelength range starting from 0.532to1.064μm0.532to1.064μm for both TE and TM polarizations. Quantum chemical calculations both on the semiempirical and on the ab initio level are carried out in order to calculate the first-order molecular polarizability tensors of the polymer repeat units. From the obtained tensor elements, theoretical values for both the average refractive indices and the maximum expectable birefringence are calculated. Based on these values a more detailed interpretation of the experimental findings is carried out. The dispersion of refractive index is quantified by the value of Abbe’s constant (νd)(νd). In our case the value νd≈11νd≈11 indicates high dispersion in the visible spectral range. The imaginary part kk of the complex refractive index n∗=n−ikn*=n−ik reaches values of k⩽10−3k⩽10−3 in the wavelength range from 0.5to1μm0.5to1μm. Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9761 SN - 1089-7550 VL - 100 IS - 6 ER - TY - JOUR A1 - Yeshchenko, Oleg A. A1 - Dmitruk, Igor M. A1 - Grytsenko, Kostyantyn A1 - Prokopets, Vadym M. A1 - Kotko, Andriy V. A1 - Schrader, Sigurd T1 - Influence of interparticle interaction on melting of gold nanoparticles in Au/polytetrafluoroethylene nanocomposites JF - Journal of Applied Physics N2 - The temperature dependence of the surface plasmon resonance energy and width in 5 nm spherical gold nanoparticles embedded in a polymer polytetrafluoroethylene matrix has been studied using absorption spectroscopy. The jumplike features have been observed in these dependences indicating the melting of gold nanoparticles at temperatures considerably lower than the bulk melting point. The interaction between gold nanoparticles sufficiently affects the melting of nanoparticles. The increase in the filling factor of the particles leads to a decrease in the melting temperature of gold nanoparticles. Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9759 SN - 1089-7550 VL - 105 IS - 9 ER - TY - CHAP A1 - Grytsenko, Kostyantyn A1 - Slominskii, Yu L. A1 - Tolmachev, O. I. A1 - Resel, R. A1 - Ksensov, S. A1 - Schrader, Sigurd T1 - Enigma of the second harmonic generation in oriented film of symmetric squaraine N2 - Second harmonic generation (SHG) in the oriented film of symmetric squaraine (Sq) was studied. Oriented Sq film on aligned polytetrafluoroethylyne (PTFE) sublayer prepared by vacuum deposition with subsequent rubbing using a cloth has been obtained. However, the mechanisms of orientation and SHG are still not clear. Methyl and ethyl substituted hydroxyl-Sq (OHSq) compounds formed oriented films with dichroic ratio of 8 on PTFE layer but with dichroic ratio of 1,5 on Teflon AF. Second layer deposition of Me-OHSq on Et-OHSq or of Et-OHSq on Me-OHSq led to an increase of the film dichroic ratio. Only the film, where Me-OHSq was first layer, exhibits an increase of SHG signal after deposition of second layer. Small differences in bi-layered OHSq films structure was detected by X-Ray diffraction (XRD) spectra. KW - dye KW - solid KW - film KW - squaraine KW - optical spectra KW - deposition KW - second harmonic generation Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15183 SP - 324 EP - 331 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Grytsenko, Kostyantyn A1 - Doroshenko, T. A1 - Kolomzarov, Yurii A1 - Prokopets, Vadym M. A1 - Fedoriak, O. A1 - Zelinski, R. A1 - Lytvyn, Oksana A1 - Prescher, Dietrich A1 - Grimm, Bernd A1 - Ksianzou, Viachaslau A1 - Schrader, Sigurd A1 - Tolmachev, O. I. A1 - Slominskii, Yu L. A1 - Kurdiukov, V. A1 - Smirnova, G. T1 - Research on the growth of dye film in vacuum in situ N2 - Organic film deposition in vacuum is fast developing scientific and industrial domain. We developed installation for deposition of organic films equipped with optical spectrometer for measurements in situ. We are developing new dyes aimed for application in waveguide sensor, nonlinear optics and studying film organisation during deposition. Fluorinated azo-dyes and azomethine dyes were synthesized at University of Applied Sciences Wildau and at the Institute of Organic Chemistry, Kyiv. Compounds were evaporated at a pressure of 10-3 Pa using resistive heated crucible. Glass and glass covered with polytetrafluoroethylene (PTFE) film are used as substrates. The films were studied with Polytec and StellarNet spectrometers and an atomic force microscope. Optical spectra of the dye films revealed, that some compounds were decomposed during evaporation. Several kinds of dyes were evaporated and deposited without decomposition. Some deposited films formed H-aggregates and other types of aggregates. AFM images of dye films showed that their morphology depends on the chemical structure of the compounds and on the nature of the substrate on which the film was grown. KW - dye KW - solid KW - film KW - in situ KW - optical spectra KW - vacuum deposition Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15206 SP - 318 EP - 323 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Bauer, Joachim A1 - Heinrich, Friedhelm A1 - Fursenko, Oksana A1 - Marschmeyer, Steffen A1 - Bluemich, Adrian A1 - Pulwer, Silvio A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Mai, Andreas A1 - Schrader, Sigurd T1 - Very high aspect ratio through silicon via reflectometry T2 - Proceedings of SPIE N2 - 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. Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13758 SN - 1996-756X ER - TY - JOUR A1 - Grytsenko, Kostyantyn A1 - Schrader, Sigurd A1 - Detert, Heiner T1 - Ultra-stable dye-filled polytetrafluoroethylene thin films JF - Nanoscience & Technology: Open Access N2 - Polytetrafluoroethylene (PTFE) and polyparaphenylene sulphide (PPS) thin films filled with molecules of different dyes were obtained by co-deposition in vacuum. The PTFE matrix prevented aggregation of dye molecules more strongly, than PPS matrix. During heating PTFE matrix kept the dye molecules in not aggregated state up to dye decomposition temperature. Dyes of all types, buried in the PTFE matrix, exhibited high stability toward actions of external factors: light, temperature, acids. KW - dye KW - PTF KW - PPS KW - nanocomposite KW - thin film KW - optical spectra KW - stability Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-5947 SN - 2374-8141 VL - 1 IS - 2 ER - TY - JOUR A1 - Bauer, Joachim A1 - Gutke, Marko A1 - Heinrich, Friedhelm A1 - Edling, Matthias A1 - Stoycheva, Vesela A1 - Kaltenbach, Alexander A1 - Burkhardt, Martin A1 - Gruenefeld, Martin A1 - Gamp, Matthias A1 - Gerhard, Christoph A1 - Steglich, Patrick A1 - Steffen, Sebastian A1 - Herzog, Michael A1 - Dreyer, Christian A1 - Schrader, Sigurd T1 - Novel UV-transparent 2-component polyurethane resin for chip-on-board LED micro lenses JF - Optical Materials Express N2 - In this work we present a novel optical polymer system based on polyurethane elastomer components, which combines excellent UV transparency with high thermal stability, good hardness, high surface tension and long pot life. The material looks very promising for encapsulation and microlensing applications for chip-on-board (CoB) light-emitting diodes (LED). The extinction coefficient k, refractive index n, and bandgap parameters were derived from transmission and reflection measurements in a wavelength range of 200-890 nm. Thermogravimetry and differential scanning calorimetry were used to provide glass transition and degradation temperatures. The surface tension was determined by means of contact angle measurements. As proof of concept, a commercial InGaN-CoB-LED is used to demonstrate the suitability of the new material for the production of microlenses. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13472 SN - 2159-3930 VL - 10 IS - 9 SP - 2085 EP - 2099 ER - TY - CHAP A1 - Prelipceanu, Marius A1 - Cojocariu, Lucian A1 - Graur, Adrian A1 - Schrader, Sigurd T1 - Analysis of thermally stimulated processes in new phenanthroline derivatives suitable for optoelectronic devices T2 - Journal of Physics: Conference Series (JPCONF) N2 - Thermally stimulated processes have been studied in thin films of phenanthroline derives to describe the states that had been localized. Ultraviolet Photoelectron Spectroscopy had checked out before thin films of new pyrrolo[l,2-a][l,10] phenanthroline derivatives [1], in order to further applications in optoelectronic devices. The investigated compounds have an electronic band structure which is due to the substituent (R=NO2, Cl) induced transformations of molecular orbitals. Thermally stimulated discharge currents (TSDC) attested dipolar and charge transport mechanisms. Each TSDC peak has been assigned to elementary processes that are different utilizing in addition dielectric spectroscopy (DES), and the mean trap depths have been approximated from thermally stimulated luminescence (TSL) curves. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-12050 SN - 1742-6596 VL - 585 ER - TY - CHAP A1 - Messaoudi, Hamza A1 - Das, Susanta Kumar A1 - Lange, Janine A1 - Heinrich, Friedhelm A1 - Schrader, Sigurd A1 - Frohme, Marcus A1 - Grunwald, Rüdiger T1 - Femtosecond laser induced nanostructuring for surface enhanced Raman spectroscopy N2 - The formation of periodical nanostructures with femtosecond laser pulses was used to create highly efficient substrates for surface-enhanced Raman spectroscopy (SERS). We report about the structuring of silver and copper substrates and their application to the SERS of DNA (herring sperm) and protein molecules (egg albumen). The maximum enhancement factors were found on Ag substrates processed with the second harmonic generation (SHG) of a 1-kHz Ti:sapphire laser and structure periods near the SHG wavelength. In the case of copper, however, the highest enhancement was obtained with long-period ripples induced with at fundamental wavelength. This is explained by an additional significant influence of nanoparticles on the surface. Nanostructured areas in the range of 1.25 mm2 were obtained in 10 s. The surfaces were characterized by scanning electron microscopy, Fast Fourier Transform and Raman spectroscopy. Moreover, the role of the chemical modification of the metal structures is addressed. Thin oxide layers resulting from working in atmosphere which improve the biocompatibility were indicated by vibration spectra. It is expected that the detailed study of the mechanisms of laser-induced nanostructure formation will stimulate further applications of functionalized surfaces like photocatalysis, selective chemistry and nano-biology. KW - laser-induced periodic surface structure KW - surface enhanced Raman spectroscopy KW - SERS KW - metal nanostructure KW - bio-molecule KW - DNA KW - femtosecond laser KW - ultrashort pulse Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15252 SP - 61 EP - 68 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - GEN A1 - Lange, Janine A1 - Messaoudi, Hamza A1 - Das, Susanta Kumar A1 - Grunwald, Rüdiger A1 - Schrader, Sigurd A1 - Frohme, Marcus A1 - Heinrich, Friedhelm T1 - Analyse komplexer biologischer Proben mittels oberflächenverstärkter Ramanspektroskopie (SERS) T2 - Wissenschaftliche Beiträge 2014 N2 - Diese Studie beschäftigt sich mit dem Nachweis biologischer Proben mit Hilfe der Raman-Mikroskopie. Um ausreichende Signalintensitäten auch bei niedrigen Konzentrationen zu erhalten, wurde insbesondere der Effekt der oberflächenverstärkten Raman-Streuung (SERS) näher untersucht. Als Proben dienten DNA aus Hering-Sperma und das Protein Albumin. Zur Verstärkung des Raman-Spektrums wurden zwei unterschiedliche Methoden verwendet. Zum Einen wurden in einem chemischen Reduktionsprozess Nanosilberpartikel hergestellt und den biologischen Proben zugemischt. Zum Anderen wurden mit Hilfe laserangeregter periodischer Oberflächenstrukturierung (LIPSS) erzeugte nanostrukturierte Silberoberflächen als Substrate für die Proben verwendet. Diese Methode wurde bislang nicht für die SERS-Analyse biologischer Proben eingesetzt. Erste hier präsentierte Messungen zeigen, dass beide Verfahren signifikante SERS-Verstärkungen liefern und potentiell leistungsstarke Methoden für die zerstörungsfreie Analyse biologischer Proben darstellen. Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-3300 SN - 0949-8214 VL - 18 SP - 27 EP - 32 ER - TY - JOUR A1 - Minaev, Boris A1 - Jansson, Emil A1 - Ågren, Hans A1 - Schrader, Sigurd T1 - Theoretical study of phosphorescence in dye doped light emitting diodes JF - The Journal of Chemical Physics N2 - Phosphorescence of platinum(II) octaethyl porphyrin (PtOEP), which has been used in organic light emitting diodes to overcome the efficiency limit imposed by the formation of triplet excitons, is studied by time-dependent (TD) density functional theory (DFT). Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9775 SN - 1089-7690 VL - 125 IS - 23 ER - TY - GEN A1 - Tudose, Ovidiu-Gelu A1 - Schrader, Sigurd A1 - Thiem, Heiko T1 - Scanning probe investigations of morphology of new p-type material for organic field-effect transistors T2 - Wissenschaftliche Beiträge 2005 N2 - Organic electronics is a fast growing field of research and technological developments. First applications based on organic electronics have been available on the market for a couple of years, so high resolution colour displays based on organic light-emitting devices are used in digital cameras or mobile phones. Efforts are still going on to find better materials and for a better understanding structure property relationships of organic semiconductors. Although exemplary applications have been realized from polymers and amorphous layers of evaporable molecular materials, crystalline organic semiconductors receive intense attention because the charge-carrier mobilities in these materials are much higher than in polymers or amorphous layers. After optimizing the electronic properties of organic devices (e.g. organic field-effect transistors or organic light emitting diodes) and demonstration of fundamental devices, attention has turned to morphology and composition of the films. Understanding and controlling the morphology of organic films will have a significant impact on the performance of organic-based devices, e.g. by minimizing the number of grain boundaries in the active region of an organic field-effect transistor (OFET). Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-4263 SN - 0949-8214 VL - 10 SP - 70 EP - 73 ER - TY - GEN A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Pulwer, Silvio A1 - Bauer, Joachim A1 - Heinrich, Friedhelm A1 - Casalboni, Mauro A1 - Schrader, Sigurd T1 - Advanced Nanophotonics: Silicon-Organic Hybrid Technology T2 - Wissenschaftliche Beiträge 2016 N2 - Integrated photonic devices have gained increasing research interests. Especially silicon photonics have become very attractive for various optical applications. Using silicon-on-insulator as a material platform provides the ability to fabricate photonic devices with electronic devices on a single chip. Driven by substantial research investments, the integration of photonic devices on silicon-on-insulator substrates has reached a degree of maturity that already permits industrial adoption. However, silicon has the disadvantage of linear electro-optical effects, and, therefore, advanced modulation formats are difficult to realize when using silicon-based high-speed modulators. Hence, a new approach was proposed: the silicon-organic hybrid technology. This technology is a viable extension of the silicon-on-insulator material system for efficient high-speed modulation. We herewith present our theoretical and experimental investigations of the silicon-organic hybrid slot-waveguide ring resonator. The advanced device design is described in detail, which allows using both, the efficient silicon-on-insulator strip-waveguides and the silicon-organic hybrid slot-waveguides in single ring resonator. For the first time, we report the transmission spectra of such a resonator covered with an electro-optical polymer. N2 - Integrierte photonische Bauelemente werden in der Forschung immer bedeutender. Besonders die Siliziumphotonik ist für verschiedene optische Anwendungen sehr attraktiv. Die Verwendung von Silizium-auf-Isolator-Materialsystemen bietet die Möglichkeit, photonische Bauelemente mit elektronischen Geräten auf einem einzelnen Chip zu entwickeln. Durch erhebliche Forschungsinvestitionen hat die photonische Integration auf Silizium-auf-Isolator-Substraten einen Reifegrad, der bereits Industriemaßstäben genügt. Jedoch hat Silizium keinen linearen elektrooptischen Effekt und damit sind moderne Modulationsformate nur schwierig zu realisieren. Daher wird seit eingen Jahren ein neuer Ansatz, die Silizium-Organik Hybridtechnologie, verfolgt. Diese Technologie ist eine tragfähige Ausdehnung des Silizium-auf-Isolator-Materialsystems für eine effiziente Hochgeschwindigkeitsmodulation und optische Signalverarbeitung. In diesem Artikel präsentieren wir unsere theoretischen und experimentellen Untersuchungen zu einem Silizium-Organik Hybrid Ringresonator. Das Design und die Herstellung des neuartigen nanophotonischen Bauelements werden im Detail beschrieben. Der demonstrierte Ringresonator kombiniert die Vorteile zweier verschiedener Wellenleiterarten in einem einzelnen Ring, dem verlustarmen Kanal-Wellenleiter und dem Silizium-organischen Hybridschlitzwellenleiter. Wir demonstrieren erstmals ein Transmissionsspektrum eines solchen Ringresonators, der mit einem elektro-optischen Polymer beschichtet ist. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-5337 SN - 0949-8214 VL - 20 SP - 45 EP - 48 ER - TY - CHAP A1 - Badoni, Davide A1 - Bonaiuto, Vincenzo A1 - Casalboni, Mauro A1 - De Matteis, Fabio A1 - Di Giuseppe, Giovanni A1 - Frontini, Luca A1 - Gunnella, Roberto A1 - Liberali, Valentino A1 - Mai, Andreas A1 - Paoluzzi, Giovanni A1 - Prosposito, Paolo A1 - Salamon, Andrea A1 - Salina, Gaetano A1 - Sargeni, Fausto A1 - Schrader, Sigurd A1 - Stabile, Alberto A1 - Steglich, Patrick ED - Prosposito, Paolo T1 - Characterization and Tests of Different Mach-Zehnder Silicon Photonic Modulator Configurations T2 - Photonics and Photoactive Materials N2 - We designed and produced an integrated silicon photonic circuit, in a single chip with IHP SG25H4_EPIC 0.25 µm technology. A Mach-Zehnder interferometer with an alternative shape for better integration, together with a standard-shape Mach-Zehnder interferometer have been realized. In this work, preliminary results of comparative performance measurements between the two Mach-Zehnder interferometer are shown. KW - CMOS KW - Mach-Zehnder KW - VLSI Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13731 SN - 978-1-64490-071-0 SP - 1 EP - 5 PB - Materials Research Forum LLC CY - Millersville, PA ER - TY - JOUR A1 - Lux, Helge A1 - Siemroth, Peter A1 - Sgarlata, Anna A1 - Prosposito, Paolo A1 - Schubert, Markus Andreas A1 - Casalboni, Mauro A1 - Schrader, Sigurd T1 - Synthesis of graphene-like transparent conductive films on dielectric substrates using a modified filtered vacuum arc system JF - Journal of Applied Physics N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9738 SN - 1089-7550 VL - 117 IS - 19 ER - TY - CHAP A1 - Meister, Stefan A1 - Al-Saadi, Aws A1 - Franke, Bülent A. A1 - Mahdi, Shaimaa A1 - Kuhlow, Berndt A1 - Voigt, Karsten A1 - Tillack, Bernd A1 - Richter, Harald H. A1 - Zimmermann, Lars A1 - Ksianzou, Viachaslau A1 - Schrader, Sigurd A1 - Eichler, Hans J. T1 - Photonic crystal microcavities in SOI waveguides produced in a CMOS environment N2 - We have investigated microcavities in Silicon-on-Insolator (SOI) waveguides. The rectangular waveguides with 500 nm width are fabricated in the 220 nm silicon device layer. The microcavities are formed by one-dimensional photonic crystals in Fabry-Perot structure directly written in the waveguides. The SOI photonic structures are produced in a CMOS environment using 248 nm DUV lithography, where the waveguides as well as the photonic crystals are created in the same step using a single mask. In order to achieve a desired spectral shape of the filter function capable for several applications, a number of different cavities were investigated, e.g. single cavities of first and higher order as well as multi-cavity filters. The experimental results are compared with simulations of photonic crystal microcavities in strip waveguides. The spectral transmission function of such filters dependent on the design parameters are calculated by an analysis based on Finite-Difference-Time-Domain (FDTD) method. KW - silicon photonics KW - SOI waveguide KW - photonic crystal KW - band-pass filter KW - microcavity KW - FDTD simulation Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15223 SP - 330 EP - 339 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Meister, Stefan A1 - Schweda, Dawid A1 - Dziedzina, Marcus A1 - Al-Saadi, Aws A1 - Franke, Bülent A. A1 - Scharfenorth, Chris A1 - Grimm, Bernd A1 - Dufft, Daniela A1 - Schrader, Sigurd A1 - Eichler, Hans J. T1 - Single cavity filters on end-faces of optical fibers N2 - We have developed thin film Fabry-Perot filters directly coated on optical fibers to archive a high level of integration with a reduction of optical elements. Such band-pass filters can be used in fiber optical sensor systems, and for fiber communication, e.g. CWDM applications. The filters cavities consist of a single spacer and two dielectric mirrors. The dielectric mirrors are deposited by PVD directly on end-faces of single-mode optical fibers. Dielectric as well as polymeric materials were applied as the spacer layer. Polymeric spacer layers were deposited by dip coating. The influence of the mirror reflectivity on the transmission band of the Fabry-Perot filters was investigated. Furthermore, the optical performance of filters with first order (λ/2) as well as higher order spacers was analyzed. The experimental results are compared with numerical analysis of Fabry-Perot cavities on the end-face of cylindrical waveguides. The spectral characteristic of the filters are calculated using a software solving Maxwell´s equations by a FDTD method. The layer design of the filters and the deposition process were optimized for maximum transmission and narrow bandwidth of the transmission peak. Passive band-pass filters on fiber end-faces were designed, fabricated and characterized for transmission wavelengths of 945 nm, 1300 nm, as well as 1550 nm. Bandwidths as narrow as 1 nm could be achieved for 945 nm. KW - fiber optics KW - microcavity KW - optical coating KW - band-pass filter KW - Fabry-Perot filter KW - dip coating Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15214 SP - 253 EP - 261 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Meister, Stefan A1 - Al-Saadi, Aws A1 - Franke, Bülent A. A1 - Mahdi, Shaimaa A1 - Szczambura, Miroslaw A1 - Kuhlow, Berndt A1 - Woggon, Ulrike A1 - Zimmermann, Lars A1 - Richter, Harald H. A1 - Stolarek, David A1 - Schrader, Sigurd A1 - Eichler, Hans J. T1 - Micro-cavities based on width modulated SOI waveguides N2 - We have designed, fabricated and investigated one-dimensional (1D) micro-cavities in Silicon-on-Insulator (SOI) waveguides. The single mode waveguides are fabricated in a 220 nm silicon device layer. The 1D micro-cavities in Fabry-Perot structure consist of two Bragg-mirror regions formed by a sinusoidal modulation of the waveguide width. The mirror regions are separated by a sub-micron spacer. The SOI photonic structures are produced in a CMOS environment using 248 nm DUV lithography. The waveguides as well as the width modulated mirror regions are designed using a single mask and are fabricated in a shallow trench process. The transmission spectra of these width modulated micro-cavities with different mirror reflectivities and cavity lengths are investigated. Q-factors up to 855 could be observed at 1550 nm wavelength with low insertion loss of 1.9 dB. The width modulated micro-cavities, including the mirror regions, have lengths of less than 20 microns and widths of maximum 450 nm. These small foot-print cavities act as band pass filters and can be used as resonators for laser or electro-optic modulation of light. KW - silicon photonics KW - CMOS KW - SOI waveguide KW - micro-cavity KW - micro-resonator KW - band-pass filter Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15233 SP - 199 EP - 204 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - CHAP A1 - Wang, Sha A1 - Meister, Stefan A1 - Mahdi, Shaimaa A1 - Franke, Bülent A. A1 - Al-Saadi, Aws A1 - Zimmermann, Lars A1 - Richter, Harald H. A1 - Stolarek, David A1 - Lisinetskii, Viktor A1 - Ksianzou, Viachaslau A1 - Schrader, Sigurd A1 - Eichler, Hans J. T1 - Spontaneous and stimulated Raman scattering in planar silicon waveguides N2 - Raman scattering in planar silicon on insulator (SOI) waveguides with 2 μm width, 220 nm height and 2 cm length is investigated. A cw Nd:YAP laser at 1340.6 nm with 7 GHz FWHM spectral width is used as the pump source. A lensed fiber of 2.5 μm focus diameter is used to couple the pump laser into the waveguide. The coupling efficiency is estimated to be around 10%. Spontaneous Raman scattering is observed with as low as 2.5 mW pump power inside the waveguide. The spontaneous Raman spectrum is measured by an optical spectrum analyzer. The first order Raman peak is measured at around 1441.4 nm corresponding to a Raman shift of 15.6 THz, while the FWHM of Raman spectrum is measured as around 100 GHz. Maximum Raman output of around 90 pW is obtained by around 22 mW pump. The stimulated Raman gain coefficient is estimated as around 56 cm/GW from the relationship between spontaneous Raman output power and pump power. A temperature dependence of Raman frequency shift of about 0.6 GHz/K is measured. The spontaneous anti-Stokes Raman scattering output peak at 1253 nm is also observed with around 35 mW pump. Stimulated Raman amplification measurement is carried out with a SLED white light source as probe signal. With 35 mW pump power, around 0.6 dB gain has been determined with both pump and probe being TE polarized. KW - silicon waveguide KW - Raman Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15248 SP - 281 EP - 289 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - JOUR A1 - Zesch, Christoph A1 - Finkelstein, Daniel A1 - Regehly, Martin A1 - Reif, Jürgen A1 - Schrader, Sigurd T1 - Efficient nanosecond barium nitrate Raman laser for the visible spectral range JF - Optics Express N2 - We report on the design and performance of two solid-state Raman lasers, pumped by a frequency-doubled Nd:YAG laser at 532 nm (8 ns FWHM, 10 Hz, up to 10 mJ), that generate either the first or second Stokes radiation with wavelengths of 563 nm and 598 nm. Barium nitrate crystals with a 1 cm² face area and lengths of 3 cm and 5 cm were used as the Raman-active medium in stable semi-spherical resonators. The Raman lasers produced first Stokes and second Stokes pulses, achieving pulse energies up to 2.3 mJ and conversion efficiencies up to 35% (first Stokes, 5 cm crystal) and 21% (second Stokes, 5 cm crystal). The output beams exhibit nearly Gaussian profiles with beam quality factors of M² = 1.67 and M² = 1.83, respectively. The proposed design and characterization demonstrated a Raman laser with high efficiency and superior beam quality. After subsequent frequency doubling, the output appears well dedicated for future differential absorption LiDAR (DIAL) applications. KW - Gaussian beam KW - laser source KW - Nd:YAG laser KW - Raman laser KW - solid state laser KW - ultraviolet laser Y1 - 2026 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-21320 VL - 34 IS - 4 SP - 6355 EP - 6363 PB - Optica ER - TY - CHAP A1 - Pulwer, Silvio A1 - Fiebelkorn, Richard A1 - Zesch, Christoph A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Villasmunta, Francesco A1 - Gedat, Egbert A1 - Handrich, Jan A1 - Schrader, Sigurd A1 - Vandenhouten, Ralf T1 - Endoscopic orientation by multimodal data fusion T2 - Proc. SPIE 10931, MOEMS and Miniaturized Systems XVIII N2 - 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. KW - endoscope KW - orientation KW - Kalman filter KW - visual odometry KW - mems KW - gyroscope KW - accelerometer Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-11420 SN - 1996-756X ER - TY - CHAP A1 - Zesch, Christoph A1 - Schrader, Sigurd A1 - Prosposito, Paolo A1 - Lux, Oliver A1 - Eichler, Hans J. T1 - Raman lasers for trace gas detection N2 - The emission of commercial solid-state lasers is shifted by Raman lasers to selected wavelengths suitable for trace gas detection. High power Raman lasers based on Ba(NO3)2, diamond and silicon detect CO2, O3 and H2O. Raman lasers base on the physical effect of stimulated Raman scattering. Two new Raman crystals (Spodumene and LuAlO3) are investigated and their SRS-spectra is shown. KW - stimulated Raman scattering KW - Raman laser KW - Barium nitrate KW - Nd:YAG laser KW - trace gas detection Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15351 SP - 114 EP - 119 PB - SPIE ER - TY - JOUR A1 - Villasmunta, Francesco A1 - Heise, Patrick A1 - Breiter, Manuela A1 - Schrader, Sigurd A1 - Schenk, Harald A1 - Regehly, Martin A1 - Mai, Andreas T1 - Monolithically Integrated Optical Through-Silicon Waveguides for 3D Chip-to-Chip Photonic Interconnects JF - IEEE Journal of Selected Topics in Quantum Electronics N2 - The scaling limitations of electrical interconnects are driving the demand for efficient optical chip-to-chip links. We report the first monolithic integration of air-clad optical through-silicon waveguides in silicon, fabricated via Bosch and cryogenic deep reactive-ion etching. Rib, single-bridge, and double-bridge designs with 50 μm cores and up to 150 μm propagation lengths have been evaluated. Cryogenic-etched rib waveguides achieve the highest median transmission (66%, −1.80 dB), compared to Bosch-etched ribs (62%, −2.08 dB). Across all geometries, 3 dB alignment windows range from 9.3 μm to 49.2 μm, with Bosch-etched double-bridge waveguides providing the broadest tolerance. We show that geometric fidelity outweighs sidewall roughness for transmission and alignment in these large-core, multimode optical through-silicon waveguides. This technology provides a scalable, complementary metal-oxide semiconductor-compatible pathway toward 3D photonic interconnects. KW - optical waveguide KW - optical device fabrication KW - silicon KW - three-dimensional display KW - optical loss KW - optical interconnection KW - coupling KW - optical surface wave KW - optical coupling KW - coupler KW - silicon photonics KW - three-dimensional integrated circuit KW - through-silicon vias (TSV) Y1 - 2026 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-20828 VL - 32 IS - 2 PB - IEEE ER - TY - JOUR A1 - Steglich, Patrick A1 - Mai, Christian A1 - Villringer, Claus A1 - Dietzel, Birgit A1 - Bondarenko, Siegfried A1 - Ksianzou, Viachaslau A1 - Villasmunta, Francesco A1 - Zesch, Christoph A1 - Pulwer, Silvio A1 - Burger, Martin A1 - Bauer, Joachim A1 - Heinrich, Friedhelm A1 - Schrader, Sigurd A1 - Vitale, Francesco A1 - De Matteis, Fabio A1 - Prosposito, Paolo A1 - Casalboni, Mauro A1 - Mai, Andreas T1 - Silicon-organic hybrid photonics: an overview of recent advances, electro-optical effects and CMOS integration concepts JF - Journal of Physics: Photonics N2 - In recent decades, much research effort has been invested in the development of photonic integrated circuits, and silicon-on-insulator technology has been established as a reliable platform for highly scalable silicon-based electro-optical modulators. However, the performance of such devices is restricted by the inherent material properties of silicon. An approach to overcoming these deficiencies is to integrate organic materials with exceptionally high optical nonlinearities into a silicon-on-insulator photonic platform. Silicon–organic hybrid photonics has been shown to overcome the drawbacks of silicon-based modulators in terms of operating speed, bandwidth, and energy consumption. This work reviews recent advances in silicon–organic hybrid photonics and covers the latest improvements to single components and device concepts. Special emphasis is given to the in-device performance of novel electro-optical polymers and the use of different electro-optical effects, such as the linear and quadratic electro-optical effect, as well as the electric-field-induced linear electro-optical effect. Finally, the inherent challenges of implementing non-linear optical polymers on a silicon photonic platform are discussed and a perspective for future directions is given. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13882 SN - 2515-7647 VL - 3 IS - 2 ER - TY - CHAP A1 - Villasmunta, Francesco A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Schrader, Sigurd A1 - Schenk, Harald A1 - Mai, Andreas A1 - Regehly, Martin ED - Chen, Ray T. ED - Schröder, Henning T1 - Design, fabrication, and characterization of integrated optical through-silicon waveguides for 3D photonic interconnections T2 - Optical Interconnects XXIV N2 - In the context of an ever-growing volume of data generated by established and emerging technologies, such as 5G, the Internet of Things, artificial intelligence, machine learning, blockchain, and virtual reality, faster communication speed is demanded by data centers and high-performance computing. Transceiver requirements surged from 100 to 400 Gb/s and beyond. In this scenario, photonics aims to enable Tb/s optical communication at energies below 1 pJ/bit. Targeting higher communication rates while maintaining a low power budget can significantly benefit from 3D photonic chip architectures. This paper presents the simulation-based design, fabrication, and characterization of a monolithically integrated optical through-silicon waveguide that facilitates the connection between different surfaces of a silicon chip. Deep reactive ion etching was employed in both the Bosch and Cryogenic variants to evaluate the effect of sidewall roughness on propagation losses. The mechanical stability of the waveguide was ensured by interrupting the annular trench with a bridging structure. The high-refractive-index contrast to air provides tight light confinement for a core size of up to 50 μm and multimode operation at 1550 nm. The morphology was characterized using scanning electron microscopy (SEM), and optical transmission characterization was performed using relative power loss measurements. A tunable laser source was buttcoupled to a waveguide to analyze light transmission efficiency. Preliminary measurements using single-mode fiber show that the transmitted values exceeded 99% for all structures. KW - multimode photonics KW - cryogenic etching KW - ICP-DRIE KW - optical interconnects KW - silicon photonics KW - 3D chip stacking Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-19759 VL - 12892 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER - TY - JOUR A1 - Bauer, Joachim A1 - Fursenko, Oksana A1 - Marschmeyer, Steffen A1 - Heinrich, Friedhelm A1 - Villasmunta, Francesco A1 - Villringer, Claus A1 - Zesch, Christoph A1 - Schrader, Sigurd T1 - Spectroscopic reflectometry for characterization of Through Silicon Via profile of Bosch etching process JF - Journal of Vacuum Science & Technology B N2 - Through Silicon Via (TSV) technology is a key in 3D integration of circuits by the creation of interconnects using vias, which go through the full silicon wafer. Typically, a highly-selective Bosch Si etch process is used. It is characterized by a high etch rate at a high aspect ratio, whereby scallops on the sidewalls are generated. In this work, square via arrays with dimensions from 3 to 50 μm and up to 300 μm depth were fabricated and analyzed by spectroscopic reflectometry. The reflectometric data are compared to simulations by a novel theoretical approach. In order to simulate the reflectance spectra of TSV arrays, a combination of 2D and 3D rigorous coupled wave analysis was applied. Besides the via depth, the sidewall angle and the corner radius of the bottom profile were considered in the model. The general requirements on spectral resolution in TSV metrology are discussed. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16093 VL - 37 IS - 6 PB - American Vacuum Society (AVS) ER - TY - GEN A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Pulwer, Silvio A1 - Dietzel, Birgit A1 - Ksianzou, Viachaslau A1 - Schrader, Sigurd T1 - Chip-integrierte photonische Bauelemente T2 - Wissenschaftliche Beiträge 2017 N2 - In unserer hochtechnologisierten Gesellschaft spielt die optische Datenübertragung aufgrund der stetig wachsenden Informationsvielfalt eine immer bedeutendere Rolle. In den Anfängen der Nachrichtentechnik waren Datenraten von wenigen bit/s realisierbar. Heute werden mittels optischer Technologien Übertragungsraten von mehreren Gbit/s umgesetzt. Möglich wird dies durch neue Entwicklungen in der Chip-integrierten Photonik. Beispiele dafür sind Chip-integrierte elektrooptische Modulatoren und Schalter. In diesem Artikel werden neue Entwicklungen in der Chip-integrierten Photonik diskutiert und die experimentelle Charakterisierung der Bauelemente in Form eines Ringresonators beschrieben. Für die Experimente wird exemplarisch ein photonisches Bauelement genutzt, das aus einem hybriden Silizium-Polymer-Materialsystem besteht. Die Ergebnisse zeigen, dass diese Materialkombination vielversprechend für zukünftige Chip-integrierte photonische Bauelemente mit extrem geringem Energiebedarf ist. N2 - The focus on high-tech in our society makes optical data transmission increasingly important due to the continually growing diversity of information. At the very beginning of integrated photonics, the data rates achieved were only a few bit/s. Today, transfer rates of several Gbit/s are possible due to novel chip-integrated devices such as electro-optical modulators and switches. This trend was made possible due to new developments in the field of Chip-integrated photonics. In this article, we discuss latest developments in the field of chip-integrated photonic devices and describe their experimental characterization. The experimental setup is developed and described in detail. The example used in our experiments is a hybrid silicon-polymer material system. Our results show that the hybrid material approach is a promising candidate for future on-chip integrated photonic devices with low power consumption. Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9426 SN - 0949-8214 VL - 21 SP - 55 EP - 59 ER - TY - GEN A1 - Steglich, Patrick A1 - Ksianzou, Viachaslau A1 - Villringer, Claus A1 - Pulwer, Silvio A1 - Schrader, Sigurd T1 - Theorie der Modenlinienspektroskopie zur optischen Charakterisierung von Polymerschichten T2 - Wissenschaftliche Beiträge 2018 N2 - Die Modenlinienspektroskopie kann zur hochpräzisen Charakterisierung von Polymerschichten bezüglich des Brechungsindex verwendet werden. Das vorliegende Manuskript behandelt die Theorie der Modenlinienspektroskopie und beginnt dabei mit den theoretischen Grundlagen eines planaren Wellenleiters, die zum Verständnis der Modenlinienspektroskopie notwendig sind. Die hier präsentierten expliziten Herleitungen können genutzt werden, um die Modenlinienspektroskopie so zu modifizieren, dass auch die Messung des Pockelseffektes möglich ist. Eine Anwendungsmöglichkeit soll in der zukünftigen Bestimmung des Pockelskoeffizienten bestehen, der für die Weiterentwicklung von polymerbasierten elektrooptischen Modulatoren benötigt wird. Zudem werden der Aufbau und die experimentelle Herangehensweisen beschrieben und die Brechungsindexbestimmung wird exemplarisch am Beispiel einer Wirt-Gast-Polymerschicht demonstriert. N2 - M-Line spectroscopy can be used for high precision measurements of polymer layers. The present manuscript deals with the theory of m-line spectroscopy and thus begins with the theoretical background of a planar waveguide structure, which is necessary for a deeper understanding of m-line spectroscopy. The explicit derivations presented here can be used to modify the m-line spectroscopy in such a way that the measurement of the Pockels effect is also possible. One application is to be obtained in the future configuration of the Pockels coefficients, which is needed to optimize electro-optical modulators. In addition, the set-up and the experimental approach are described. Finally, a host-guest polymer layer is experimentally characterized in terms of the refractive index. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-10248 SN - 0949-8214 VL - 22 SP - 31 EP - 38 ER - TY - JOUR A1 - Steglich, Patrick A1 - Mai, Christian A1 - Villringer, Claus A1 - Pulwer, Silvio A1 - Casalboni, Mauro A1 - Schrader, Sigurd A1 - Mai, Andreas T1 - Quadratic electro-optic effect in silicon-organic hybrid slot-waveguides JF - Optics Letters N2 - 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. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-12148 SN - 1539-4794 VL - 43 IS - 15 ER -