TY - JOUR A1 - Steglich, Patrick A1 - Mai, Christian A1 - Villringer, Claus A1 - Mai, Andreas T1 - Direct observation and simultaneous use of linear and quadratic electro-optical effects JF - Journal of Physics D: Applied Physics N2 - We report on the direct observation and simultaneous use of the linear and quadratic electro-optical effect and propose a method by which higher-order susceptibilities of electro-optical materials can be determined. The evaluation is based on the separation of the second- and third-order susceptibilities and the experimental technique uses a slot waveguide ring resonator fabricated in integrated photonic circuit technology, which is embedded by a guest-host polymer system consisting of the azobenzene dye Disperse Red 1 in a poly(methyl methacrylate) matrix as an active electro-optical material. The contribution of both effects on the electro-optical response under the influence of static and time-varying electrical fields is investigated. We show that the quadratic electro-optical effect has a significant influence on the overall electro-optical response even with acentric molecular orientated molecules. Our findings have important implications for developing electro-optical devices based on polymer-filled slot waveguides and give rise to advanced photonic circuits. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13032 SN - 1361-6463 VL - 53 IS - 12 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 - Bondarenko, Siegfried A1 - Villringer, Claus A1 - Steglich, Patrick T1 - Comparative Study of Nano-Slot Silicon Waveguides Covered by Dye Doped and Undoped Polymer Cladding JF - Applied Sciences N2 - Nonlinear optical dyes doped in optical polymer matrices are widely used for electro-optical devices. Linear optical properties change with dye concentration, which leads to a change in modal properties, especially in nano-structured integrated waveguides such as silicon slot-waveguides. Here, we investigate the influence of a nonlinear optical dye on the performance of a silicon-organic hybrid slot-waveguide. A simulation study of the modal and optical confinement properties is carried out and dependence of the structural parameters of the slot-waveguide and the organic cladding material is taken into account. As cladding material, a guest-host polymer system is employed comprising the nonlinear optical dye Disperse Red 1 (DR1) doped in a poly[methyl methacrylate] (PMMA) matrix. The refractive indices of doped and undoped PMMA were deduced from ellipsometric data. We present a guideline for an optimized slot-waveguide design for the fabrication in silicon-on-insulator technology giving rise to scalable, high-performance integrated electro-optical modulators. KW - silicon photonics KW - modeling and simulation at the nanoscale KW - nonlinear optics at the nanoscale KW - slot waveguide KW - silicon-on-insulator technology Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-10716 SN - 2076-3417 VL - 9 IS - 1 PB - MDPI ER - TY - JOUR A1 - Steglich, Patrick A1 - Hülsemann, Marcel A1 - Dietzel, Birgit A1 - Mai, Andreas T1 - Optical Biosensors Based on Silicon-On-Insulator Ring Resonators: A Review JF - Molecules N2 - Recent developments in optical biosensors based on integrated photonic devices are reviewed with a special emphasis on silicon-on-insulator ring resonators. The review is mainly devoted to the following aspects: (1) Principles of sensing mechanism, (2) sensor design, (3) biofunctionalization procedures for specific molecule detection and (4) system integration and measurement set-ups. The inherent challenges of implementing photonics-based biosensors to meet specific requirements of applications in medicine, food analysis, and environmental monitoring are discussed. KW - biosensor KW - biophotonics KW - integrated optical sensor KW - aptamer KW - biomaterial KW - optical sensor KW - silicon photonics KW - ring resonator KW - lab-on-a-chip Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-10822 SN - 1420-3049 VL - 24 IS - 3 ER - TY - CHAP A1 - Steglich, Patrick ED - You, Kok Yeow T1 - Silicon-on-Insulator Slot Waveguides: Theory and Applications in Electro-Optics and Optical Sensing T2 - Emerging Waveguide Technology N2 - This chapter deals with the basic concept of silicon-on-insulator (SOI) slot waveguides,including slot waveguide theory, fabrication steps, and applications. First, in the theorysection, a modal field expression and the characteristic equation is derived, which is alsovalid for higher-order modes. SOI slot waveguide structures are simulated and character-istic values like the effective refractive indices and the field confinement factors are deter-mined. The fabrication section describes typical SOI fabrication steps and the limits ofcurrent fabrication techniques. Additionally, developments regarding loss reduction inSOI slot waveguides are given from the fabrication point of view. This is followed by thetheory and practice of slot waveguide based electro-optical modulators. Here, the SOI slotwaveguide is embedded in an organic nonlinear optical material in order to achieverecord-low voltage-length products. In the field of optical sensors, it is shown that slotwaveguides enable remarkable waveguide sensitivity for both refractive index sensingand surface sensing. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-10563 SN - 978-1-78923-493-0 SP - 187 EP - 210 PB - IntechOpen 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 - 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 - Mai, Andreas A1 - Mai, Christian A1 - Steglich, Patrick T1 - From Lab-on-chip to Lab-in-App: Challenges towards silicon photonic biosensors product developments JF - Results in Optics N2 - This work presents and evaluates different approaches of integrated optical sensors based on photonic integrated circuit (PIC) technologies for refractive index sensing. Bottlenecks in the fabrication flow towards an applicable system are discussed that hinder a cost-effective mass-production for disposable sensor chips. As sensor device, a waveguide coupled micro-ring based approach is chosen which is manufactured in an 8” wafer level process. We will show that the co-integration with a reproducible, scalable and low-cost microfluidic interface is the main challenge which needs to be overcome for future application of silicon technology based PIC sensor chips. KW - silicon photonic sensor KW - integrated optical sensor KW - photonic integrated circuit KW - optical ring resonator KW - photonic biosensor KW - refractive index sensing KW - interchangeable sensor chip Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16687 SN - 2666-9501 VL - 9 PB - Elsevier ER - TY - JOUR A1 - Steglich, Patrick A1 - Schasfoort, Richard B. M. T1 - Surface Plasmon Resonance Imaging (SPRi) and Photonic Integrated Circuits (PIC) for COVID-19 Severity Monitoring JF - COVID N2 - Direct optical detection methods such as surface plasmon resonance imaging (SPRi) and photonic-integrated-circuits (PIC)-based biosensors provide a fast label-free detection of COVID-19 antibodies in real-time. Each technology, i.e., SPRi and PIC, has advantages and disadvantages in terms of throughput, miniaturization, multiplexing, system integration, and cost-effective mass production. However, both technologies share similarities in terms of sensing mechanism and both can be used as high-content diagnostics at or near to point of care, where the analyte is not just quantified but comprehensively characterized. This is significant because recent results suggest that not only the antibody concentration of the three isotypes IgM, IgG, and IgA but also the strength of binding (affinity) gives an indication of potential COVID-19 severity. COVID-19 patients with high titers of low affinity antibodies are associated with disease severity. In this perspective, we provide some insights into how SPR and PIC technologies can be effectively combined and complementarily used for a comprehensive COVID-19 severity monitoring. This opens a route toward an immediate therapy decision to provide patients a treatment in an early stage of the infection, which could drastically lowers the risk of a severe disease course. KW - COVID-19 KW - surface plasmon resonance KW - photonic integrated circuit KW - direct optical detection KW - COVID-19 antibody KW - COVID-19 severity KW - pandemic surveillance KW - immunity monitoring Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16004 SN - 2673-8112 VL - 2 IS - 3 SP - 389 EP - 397 PB - MDPI ER - TY - JOUR A1 - Steglich, Patrick A1 - Lecci, Giulia A1 - Mai, Andreas T1 - Surface Plasmon Resonance (SPR) Spectroscopy and Photonic Integrated Circuit (PIC) Biosensors: A Comparative Review JF - Sensors N2 - Label-free direct-optical biosensors such as surface-plasmon resonance (SPR) spectroscopy has become a gold standard in biochemical analytics in centralized laboratories. Biosensors based on photonic integrated circuits (PIC) are based on the same physical sensing mechanism: evanescent field sensing. PIC-based biosensors can play an important role in healthcare, especially for point-of-care diagnostics, if challenges for a transfer from research laboratory to industrial applications can be overcome. Research is at this threshold, which presents a great opportunity for innovative on-site analyses in the health and environmental sectors. A deeper understanding of the innovative PIC technology is possible by comparing it with the well-established SPR spectroscopy. In this work, we shortly introduce both technologies and reveal similarities and differences. Further, we review some latest advances and compare both technologies in terms of surface functionalization and sensor performance. KW - surface plasmon resonance KW - photonic integrated circuit KW - biosensor KW - surface functionalization KW - label-free detection Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16018 SN - 1424-8220 VL - 22 IS - 8 PB - MDPI 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 - Anand, Ketan A1 - Steglich, Patrick A1 - Kreissl, Jochen A1 - Chavarin, Carlos Alvarado A1 - Spirito, Davide A1 - Franck, Max A1 - Lecci, Giulia A1 - Costina, Ioan A1 - Herfurth, Norbert A1 - Katzer, Jens A1 - Mai, Christian A1 - Becker, Annette A1 - Reithmaier, Johann Peter A1 - Zimmermann, Lars A1 - Mai, Andreas T1 - Adhesive-free bonding for hetero-integration of InP based coupons micro-transfer printed on SiO2 into Complementary Metal-Oxide-Semiconductor backend for Si photonics application on 8” wafer platform JF - Thin Solid Films N2 - Micro-Transfer printing (µTP) is a promising technique for hetero-integration of III-V materials into Si-based photonic platforms. To enhance the print yield by increasing the adhesion between the III-V material and Si or SiO2 surface, an adhesion promoter like Benzocyclobutene is typically used as interlayer. In this work, we demonstrate µTP of InP based coupons on SiO2 interlayer without any adhesive interlayer and investigate the mechanism of adhesive free bonding. Source coupons are InP-based coupon stacks on a sacrificial layer that is removed by a chemical wet etch with FeCl3. For the target we fabricated amorphous-Si waveguides on 8” wafer encapsulated by a High Density Plasma SiO2 which was planarized by a chemical mechanical polishing procedure. We used O2 plasma to activate both source and target to increase adhesion between coupon and substrate. To get a better understanding of the bonding mechanism we applied several surface characterization methods. Root mean square roughness of InP and SiO2 was measured by atomic force microscopy before and after plasma activation. The step height of the micro-transfer printed source coupon on the target wafer is estimated by optical step profiler. We used Raman peak position mappings of InP to analyze possible strain and contact angle measurements on SiO2, before and after plasma activation to observe a change in the hydrophilicity of the surface. X-ray Photoelectron Spectroscopy analysis was used to characterize the surface energy states of P2p, In3d, O1s for InP source and Si2p, O1s for SiO2 target. Our results demonstrate direct bonding of InP coupons by means of µTP without the need of a strain-compensation layer. In this way, a promising route towards Complementary Metal-Oxide-Semiconductor compatible use of µTP for the hetero-integration of InP is provided. KW - hetero-integration KW - micro-transfer printing KW - indium Phosphide KW - silicon oxide KW - sacrificial layer KW - oxygen plasma activation Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-19240 SN - 0040-6090 IS - 140399 PB - Elsevier 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 - INPR A1 - Steglich, Patrick A1 - Rabus, Dominik G. A1 - Sada, Cinzia A1 - Paul, Martin A1 - Weller, Michael G. A1 - Mai, Christian A1 - Mai, Andreas T1 - Silicon Photonic Micro-Ring Resonators for Chemical and Biological Sensing: A Tutorial T2 - TechRxiv N2 - Silicon photonic micro-ring resonators (MRR) developed on the silicon-on-insulator (SOI) platform, owing to their high sensitivity and small footprint, show great potential for many chemical and biological sensing applications such as label-free detection in environmental monitoring, biomedical engineering, and food analysis. In this tutorial, we provide the theoretical background and give design guidelines for SOI-based MRR as well as examples of surface functionalization procedures for label-free detection of molecules. After introducing the advantages and perspectives of MRR, fundamentals of MRR are described in detail, followed by an introduction to the fabrication methods, which are based on a complementary metal-oxide semiconductor (CMOS) technology. Optimization of MRR for chemical and biological sensing is provided, with special emphasis on the optimization of waveguide geometry. At this point, the difference between chemical bulk sensing and label-free surface sensing is explained, and definitions like waveguide sensitivity, ring sensitivity, overall sensitivity as well as the limit of detection (LoD) of MRR are introduced. Further, we show and explain chemical bulk sensing of sodium chloride (NaCl) in water and provide a recipe for label-free surface sensing. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16840 ER - TY - JOUR A1 - Steglich, Patrick A1 - Bondarenko, Siegfried A1 - Mai, Christian A1 - Paul, Martin A1 - Weller, Michael G. A1 - Mai, Andreas T1 - CMOS-Compatible Silicon Photonic Sensor for Refractive Index Sensing Using Local Back-Side Release JF - IEEE Photonics Technology Letters N2 - Silicon photonic sensors are promising candidates for lab-on-a-chip solutions with versatile applications and scalable production prospects using complementary metal-oxide semiconductor (CMOS) fabrication methods. However, the widespread use has been hindered because the sensing area adjoins optical and electrical components making packaging and sensor handling challenging. In this work, a local back-side release of the photonic sensor is employed, enabling a separation of the sensing area from the rest of the chip. This approach allows preserving the compatibility of photonic integrated circuits in the front-end of line and metal interconnects in the back-end of line. The sensor is based on a micro-ring resonator and is fabricated on wafer-level using a CMOS technology. We revealed a ring resonator sensitivity for homogeneous sensing of 106 nm/RIU. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13649 SN - 1941-0174 VL - 32 IS - 19 SP - 1241 EP - 1244 ER - TY - CHAP A1 - Steglich, Patrick A1 - Paul, Martin A1 - Mai, Christian A1 - Böhme, Andrea A1 - Bondarenko, Siegfried A1 - Weller, Michael G. A1 - Mai, Andreas T1 - A monolithically integrated micro fluidic channel in a silicon-based photonic-integrated-circuit technology for biochemical sensing T2 - Proc. SPIE 11772, Optical Sensors 2021 N2 - In this work, a cost-effective optofluidic system is propossed and preliminary experimental results are presented. A microfluidic channel monolithically integrated into a photonic integrated circuit technology is used in conjunc- tion with a cyclo-olefin copolymer (COC) substrate to provide fluidic in- and output ports. We report on initial experimental results as well as on the simple and cost-effective fabrication of this optofluidic system by means of micro-milling. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13925 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 - Steglich, Patrick A1 - Mai, Andreas T1 - Analysis of BTO-on-Si-waveguides for energy-efficient electro-optical modulators T2 - Proc. SPIE 11775, Integrated Optics: Design, Devices, Systems and Applications VI N2 - In this work, we analyze a horizontal slot waveguide configuration, which evaluates the potential for an integration of barium titanate (BTO) based modulators into a photonic integrated circuit (PIC) technology based on siliconon- insulator (SOI) wafer. The waveguide configuration consists of a doped crystal silicon layer, a Ba0:7Sr0:3TiO3 (BST) template layer, a barium titanate (BTO) layer and a doped poly-silicon layer on top. In contrast to current approaches, we analyze the performance of this waveguide-structure by using a vertical electrode configuration that is formed by the doped silicon layer. In this way, the electric field strength is dramatically increased compared to current horizontal electrode configuration. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-13934 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 -