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Now showing 1 - 10 of 14
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    Numerical and Experimental Demonstration of Intermodal Dispersive Wave Generation
    (Weinheim : Wiley VCH, 2021) Lüpken, Niklas M.; Timmerkamp, Maximilian; Scheibinger, Ramona; Schaarschmidt, Kay; Schmidt, Markus A.; Boller, Klaus‐J.; Fallnich, Carsten
    Evidence of intermodal dispersive wave generation mediated by intermodal cross-phase modulation (iXPM) between different transverse modes during supercontinuum generation in silicon nitride waveguides is presented. The formation of a higher-order soliton in one strong transverse mode leads to phase modulation of a second, weak transverse mode by iXPM. The phase modulation enables not only supercontinuum generation but also dispersive wave generation within the weak mode, that otherwise has insufficient power to facilitate dispersive wave formation. The nonlinear frequency conversion scheme presented here suggests phase-matching conditions beyond what is currently known, which can be exploited for extending the spectral bandwidth within supercontinuum generation.
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    Nanograting-Enhanced Optical Fibers for Visible and Infrared Light Collection at Large Input Angles
    (Basel : MDPI, 2021) Wang, Ning; Zeisberger, Matthias; Hübner, Uwe; Schmidt, Markus A.
    The efficient incoupling of light into particular fibers at large angles is essential for a multitude of applications; however, this is difficult to achieve with commonly used fibers due to low numerical aperture. Here, we demonstrate that commonly used optical fibers functionalized with arrays of metallic nanodots show substantially improved large-angle light-collection performances at multiple wavelengths. In particular, we show that at visible wavelengths, higher diffraction orders contribute significantly to the light-coupling efficiency, independent of the incident polarization, with a dominant excitation of the fundamental mode. The experimental observation is confirmed by an analytical model, which directly suggests further improvement in incoupling efficiency through the use of powerful nanostructures such as metasurface or dielectric gratings. Therefore, our concept paves the way for high-performance fiber-based optical devices and is particularly relevant within the context of endoscopic-type applications in life science and light collection within quantum technology.
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    Coherent interaction of atoms with a beam of light confined in a light cage
    (London : Nature Publishing Group, 2021) Davidson-Marquis, Flavie; Gargiulo, Julian; Gómez-López, Esteban; Jang, Bumjoon; Kroh, Tim; Müller, Chris; Ziegler, Mario; Maier, Stefan A.; Kübler, Harald; Schmidt, Markus A.; Benson, Oliver
    Controlling coherent interaction between optical fields and quantum systems in scalable, integrated platforms is essential for quantum technologies. Miniaturised, warm alkali-vapour cells integrated with on-chip photonic devices represent an attractive system, in particular for delay or storage of a single-photon quantum state. Hollow-core fibres or planar waveguides are widely used to confine light over long distances enhancing light-matter interaction in atomic-vapour cells. However, they suffer from inefficient filling times, enhanced dephasing for atoms near the surfaces, and limited light-matter overlap. We report here on the observation of modified electromagnetically induced transparency for a non-diffractive beam of light in an on-chip, laterally-accessible hollow-core light cage. Atomic layer deposition of an alumina nanofilm onto the light-cage structure was utilised to precisely tune the high-transmission spectral region of the light-cage mode to the operation wavelength of the atomic transition, while additionally protecting the polymer against the corrosive alkali vapour. The experiments show strong, coherent light-matter coupling over lengths substantially exceeding the Rayleigh range. Additionally, the stable non-degrading performance and extreme versatility of the light cage provide an excellent basis for a manifold of quantum-storage and quantum-nonlinear applications, highlighting it as a compelling candidate for all-on-chip, integrable, low-cost, vapour-based photon delay.
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    Resonance-Induced Dispersion Tuning for Tailoring Nonsolitonic Radiation via Nanofilms in Exposed Core Fibers
    (Weinheim : Wiley VCH, 2020) Lühder, Tilman A.K.; Schaarschmidt, Kay; Goerke, Sebastian; Schartner, Erik P.; Ebendorff-Heidepriem, Heike; Schmidt, Markus A.
    Efficient supercontinuum generation demands for fine-tuning of the dispersion of the underlying waveguide. Resonances introduced into waveguide systems can substantially improve nonlinear dynamics in ultrafast supercontinuum generation via modal hybridization and formation of avoided crossings. Using the example of exposed core fibers functionalized by nanofilms with sub-nanometer precision both zero-dispersion and dispersive wave emission wavelengths are shifted by 227 and 300 nm, respectively, at tuning slopes higher than 20 nm/nm. The presented concept relies on dispersion management via induced resonances and can be straightforwardly extended to other deposition techniques and film geometries such as multilayers or 2D materials. It allows for the creation of unique dispersion landscapes, thus tailoring nonlinear dynamics and emission wavelengths and for making otherwise unsuitable waveguides relevant for ultrafast nonlinear photonics. © 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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    Three-dimensional spatiotemporal tracking of nano-objects diffusing in water-filled optofluidic microstructured fiber
    (Berlin : de Gruyter, 2020) Jiang, Shiqi; Förster, Ronny; Plidschun, Malte; Kobelke, Jens; Ando, Ron Fatobene; Schmidt, Markus A.
    Three-dimensional (3D) tracking of nano-objects represents a novel pathway for understanding dynamic nanoscale processes within bioanalytics and life science. Here we demonstrate 3D tracking of diffusing 100 nm gold nanosphere within a water-filled optofluidic fiber via elastic light scattering-based position retrieval. Specifically, the correlation between intensity and position inside a region of a fiber-integrated microchannel has been used to decode the axial position from the scattered intensity, while image processing-based tracking was used in the image plane. The 3D trajectory of a diffusing gold nanosphere has been experimentally determined, while the determined diameter analysis matches expectations. Beside key advantages such as homogenous light-line illumination, low-background scattering, long observation time, large number of frames, high temporal and spatial resolution and compatibility with standard microscope, the particular properties of operating with water defines a new bioanalytical platform that is highly relevant for medical and life science applications. © 2020 Shiqi Jiang et al., published by De Gruyter. 2020.
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    Ultrafast intermodal third harmonic generation in a liquid core step-index fiber filled with C2Cl4
    (Washington, DC : Soc., 2020) Schaarschmidt, Kay; Kobelke, Jens; Nolte, Stefan; Meyer, Tobias; Schmidt, Markus A.
    Third harmonic generation in a circular liquid core step-index fiber filled with a highly transparent inorganic solvent is demonstrated experimentally using ultrafast pump pulses of different durations in the telecom domain for the first time. Specifically we achieve intermodal phase matching to the HE13 higher order mode at the harmonic wavelength and found clear indications of a non-instantaneous molecular contribution to the total nonlinearity in the spectral broadening of the pump. Spectral power evolution and efficiency of the conversion process is studied for all pulse parameters, while we found the greatest photon yield for the longest pulses as well as an unexpected blue-shift of the third harmonic wavelength with increasing pump power. Our results provide the basis for future studies aiming at using this tunable fiber platform with a sophisticated nonlinear response in the context of harmonic generation. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
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    Ultrafast intermodal third harmonic generation in a liquid core step-index fiber filled with C2Cl4: erratum
    (Washington, DC : Soc., 2021) Schaarschmidt, Kay; Kobelke, Jens; Nolte, Stefan; Meyer, Tobias; Schmidt, Markus A.
    We provide a correction due to an erroneous repetition rate of one of the laser systems (90 fs pulse duration) in our previously published paper [Opt. Express28, 25037 (2020)10.1364/OE.399771].
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    3D-nanoprinted on-chip antiresonant waveguide with hollow core and microgaps for integrated optofluidic spectroscopy
    (Washington, DC : Optica, 2023) Kim, Jisoo; Bürger, Johannes; Jang, Bumjoon; Zeisberger, Matthias; Gargiulo, Julian; Menezes, Leonardo de S.; Maier, Stefan A.; Schmidt, Markus A.
    Here, we unlock the properties of the recently introduced on-chip hollow-core microgap waveguide in the context of optofluidics which allows for intense light-water interaction over long lengths with fast response times. The nanoprinted waveguide operates by the antiresonance effect in the visible and near-infrared domain and includes a hollow core with defined gaps every 176 µm. The spectroscopic capabilities are demonstrated by various absorption-related experiments, showing that the Beer-Lambert law can be applied without any modification. In addition to revealing key performance parameters, time-resolved experiments showed a decisive improvement in diffusion times resulting from the lateral access provided by the microgaps. Overall, the microgap waveguide represents a pathway for on-chip spectroscopy in aqueous environments.
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    Publisher Correction: Coherent interaction of atoms with a beam of light confined in a light cage
    (London : Nature Publishing Group, 2021) Davidson-Marquis, Flavie; Gargiulo, Julian; Gómez-López, Esteban; Jang, Bumjoon; Kroh, Tim; Müller, Chris; Ziegler, Mario; Maier, Stefan A.; Kübler, Harald; Schmidt, Markus A.; Benson, Oliver
    [no abstract available: correction of https://doi.org/10.1038/s41377-021-00556-z published online 31 May 2021; After publication of this article, it is noticed the article contained an error. In Table 1, the data in the line ‘Length (mm)’ is missing. The complete Table 1 is provided in this correction.]
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    Supercontinuum generation in a carbon disulfide core microstructured optical fiber
    (Washington, DC : Soc., 2021) Junaid, Saher; Bierlich, Joerg; Hartung, Alexander; Meyer, Tobias; Chemnitz, Mario; Schmidt, Markus A.
    We demonstrate supercontinuum generation in a liquid-core microstructured optical fiber using carbon disulfide as the core material. The fiber provides a specific dispersion landscape with a zero-dispersion wavelength approaching the telecommunication domain where the corresponding capillary-type counterpart shows unsuitable dispersion properties for soliton fission. The experiments were conducted using two pump lasers with different pulse duration (30 fs and 90 fs) giving rise to different non-instantaneous contributions of carbon disulfide in each case. The presented results demonstrate an extraordinary high conversion efficiency from pump to soliton and to dispersive wave, overall defining a platform that enables studying the impact of non-instantaneous responses on ultrafast soliton dynamics and coherence using straightforward pump lasers and diagnostics.