@article{SteglichMaiVillringeretal.2020, author = {Steglich, Patrick and Mai, Christian and Villringer, Claus and Mai, Andreas}, title = {Direct observation and simultaneous use of linear and quadratic electro-optical effects}, series = {Journal of Physics D: Applied Physics}, volume = {53}, journal = {Journal of Physics D: Applied Physics}, number = {12}, issn = {1361-6463}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13032}, year = {2020}, abstract = {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.}, language = {en} } @article{SteglichVillringerDietzeletal.2019, author = {Steglich, Patrick and Villringer, Claus and Dietzel, Birgit and Mai, Christian and Schrader, Sigurd and Casalboni, Mauro and Mai, Andreas}, title = {On-Chip Dispersion Measurement of the Quadratic Electro-Optic Effect in Nonlinear Optical Polymers Using a Photonic Integrated Circuit Technology}, series = {IEEE Photonics Journal}, volume = {11}, journal = {IEEE Photonics Journal}, number = {3}, issn = {1943-0655}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-12307}, year = {2019}, abstract = {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.}, language = {en} } @article{BondarenkoVillringerSteglich2019, author = {Bondarenko, Siegfried and Villringer, Claus and Steglich, Patrick}, title = {Comparative Study of Nano-Slot Silicon Waveguides Covered by Dye Doped and Undoped Polymer Cladding}, series = {Applied Sciences}, volume = {9}, journal = {Applied Sciences}, number = {1}, publisher = {MDPI}, issn = {2076-3417}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10716}, year = {2019}, abstract = {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.}, language = {en} } @article{SteglichHuelsemannDietzeletal.2019, author = {Steglich, Patrick and H{\"u}lsemann, Marcel and Dietzel, Birgit and Mai, Andreas}, title = {Optical Biosensors Based on Silicon-On-Insulator Ring Resonators: A Review}, series = {Molecules}, volume = {24}, journal = {Molecules}, number = {3}, issn = {1420-3049}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10822}, year = {2019}, abstract = {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.}, language = {en} } @incollection{Steglich2018, author = {Steglich, Patrick}, title = {Silicon-on-Insulator Slot Waveguides: Theory and Applications in Electro-Optics and Optical Sensing}, series = {Emerging Waveguide Technology}, booktitle = {Emerging Waveguide Technology}, editor = {You, Kok Yeow}, publisher = {IntechOpen}, isbn = {978-1-78923-493-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10563}, publisher = {Technische Hochschule Wildau}, pages = {187 -- 210}, year = {2018}, abstract = {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.}, language = {en} } @inproceedings{SteglichVillringerDuemeckeetal.2015, author = {Steglich, Patrick and Villringer, Claus and D{\"u}mecke, Silvio and Padilla-Michel, Yazmin and Casalboni, Mauro and Schrader, Sigurd}, title = {Silicon-On-Insulator Slot-Waveguide Design Trade-Offs}, series = {Proceedings of the 3rd International Conference on Photonics, Optics and Laser Technology : vol. 2}, booktitle = {Proceedings of the 3rd International Conference on Photonics, Optics and Laser Technology : vol. 2}, publisher = {SciTePress}, address = {Set{\´u}bal}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-20104}, pages = {47 -- 52}, year = {2015}, abstract = {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.}, language = {en} } @inproceedings{PadillaMichelLucciCasalbonietal.2015, author = {Padilla-Michel, Yazmin and Lucci, Massimiliano and Casalboni, Mauro and Steglich, Patrick and Schrader, Sigurd}, title = {Mechanical Characterisation of the Four Most Used Coating Materials for Optical Fibres}, series = {Proceedings of the 3rd International Conference on Photonics, Optics and Laser Technology : vol. 1}, booktitle = {Proceedings of the 3rd International Conference on Photonics, Optics and Laser Technology : vol. 1}, editor = {Ribeiro, Paulo A.}, publisher = {SciTePress}, address = {Set{\´u}bal}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-20063}, pages = {96 -- 102}, year = {2015}, abstract = {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.}, language = {en} } @article{VillringerSteglichPulweretal.2021, author = {Villringer, Claus and Steglich, Patrick and Pulwer, Silvio and Schrader, Sigurd and Laufer, Jan}, title = {Electro-optical properties of doped polymers with high transparency in the visible wavelength range}, series = {Optical Materials Express}, volume = {11}, journal = {Optical Materials Express}, number = {11}, publisher = {Optica Publishing Group}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15480}, pages = {3801 -- 3811}, year = {2021}, abstract = {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-P{\´e}rot 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.}, language = {en} } @article{MaiMaiSteglich2022, author = {Mai, Andreas and Mai, Christian and Steglich, Patrick}, title = {From Lab-on-chip to Lab-in-App: Challenges towards silicon photonic biosensors product developments}, series = {Results in Optics}, volume = {9}, journal = {Results in Optics}, publisher = {Elsevier}, issn = {2666-9501}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-16687}, year = {2022}, abstract = {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.}, language = {en} } @article{SteglichSchasfoort2022, author = {Steglich, Patrick and Schasfoort, Richard B. M.}, title = {Surface Plasmon Resonance Imaging (SPRi) and Photonic Integrated Circuits (PIC) for COVID-19 Severity Monitoring}, series = {COVID}, volume = {2}, journal = {COVID}, number = {3}, publisher = {MDPI}, issn = {2673-8112}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-16004}, pages = {389 -- 397}, year = {2022}, abstract = {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.}, language = {en} } @article{SteglichLecciMai2022, author = {Steglich, Patrick and Lecci, Giulia and Mai, Andreas}, title = {Surface Plasmon Resonance (SPR) Spectroscopy and Photonic Integrated Circuit (PIC) Biosensors: A Comparative Review}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {8}, publisher = {MDPI}, issn = {1424-8220}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-16018}, year = {2022}, abstract = {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.}, language = {en} } @article{BauerFursenkoHeinrichetal.2022, author = {Bauer, Joachim and Fursenko, Oksana and Heinrich, Friedhelm and Gutke, Marko and Kornejew, Eckhart and Br{\"o}del, Oliver and Dietzel, Birgit and Kaltenbach, Alexander and Burkhardt, Martin and Edling, Matthias and Steglich, Patrick and Herzog, Michael and Schrader, Sigurd}, title = {Determination of optical constants and scattering properties of transparent polymers for use in optoelectronics}, series = {Optical Materials Express}, volume = {12}, journal = {Optical Materials Express}, number = {1}, publisher = {Optica Publishing Group}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15666}, pages = {204 -- 224}, year = {2022}, abstract = {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\&\#x0027;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.}, language = {en} } @article{AnandSteglichKreissletal.2024, author = {Anand, Ketan and Steglich, Patrick and Kreissl, Jochen and Chavarin, Carlos Alvarado and Spirito, Davide and Franck, Max and Lecci, Giulia and Costina, Ioan and Herfurth, Norbert and Katzer, Jens and Mai, Christian and Becker, Annette and Reithmaier, Johann Peter and Zimmermann, Lars and Mai, Andreas}, title = {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}, series = {Thin Solid Films}, journal = {Thin Solid Films}, number = {140399}, publisher = {Elsevier}, issn = {0040-6090}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-19240}, year = {2024}, abstract = {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.}, language = {en} }