--- _id: '49609' abstract: - lang: eng text: The alignment of liquid crystals on surfaces plays a central role in optimizing their performances. In this work, a cutting-edge nano-lithography-based method to control the local orientation of a thermotropic liquid crystal is applied to easily available commercial standard materials and evaluated. Parallel nanogrooves on a substrate, created through 3D nanoprinting in a negative-tone photoresin optimized for two-photon polymerization are used for this purpose. Azimuthal anchoring energies of the order from 10−6 J/m2 to 10−5 J/m2 are found, depending on the spacing, width and depth of the grooves. In part, these values are larger than those reported previously for another photopolymer. Both uniform alignment and spatial patterns of different alignment directions can be realized. Electro-optic studies confirm the suitability of the method for electrically addressable photonic applications and indicate strong polar anchoring. article_number: '3467' author: - first_name: Bingru full_name: Zhang, Bingru last_name: Zhang - first_name: Malte full_name: Plidschun, Malte last_name: Plidschun - first_name: Markus A. full_name: Schmidt, Markus A. last_name: Schmidt - first_name: Heinz-Siegfried full_name: Kitzerow, Heinz-Siegfried id: '254' last_name: Kitzerow citation: ama: Zhang B, Plidschun M, Schmidt MA, Kitzerow H-S. Anchoring and electro-optic switching of liquid crystals on nano-structured surfaces fabricated by two-photon based nano-printing. Optical Materials Express. 2023;13(12). doi:10.1364/ome.503100 apa: Zhang, B., Plidschun, M., Schmidt, M. A., & Kitzerow, H.-S. (2023). Anchoring and electro-optic switching of liquid crystals on nano-structured surfaces fabricated by two-photon based nano-printing. Optical Materials Express, 13(12), Article 3467. https://doi.org/10.1364/ome.503100 bibtex: '@article{Zhang_Plidschun_Schmidt_Kitzerow_2023, title={Anchoring and electro-optic switching of liquid crystals on nano-structured surfaces fabricated by two-photon based nano-printing}, volume={13}, DOI={10.1364/ome.503100}, number={123467}, journal={Optical Materials Express}, publisher={Optica Publishing Group}, author={Zhang, Bingru and Plidschun, Malte and Schmidt, Markus A. and Kitzerow, Heinz-Siegfried}, year={2023} }' chicago: Zhang, Bingru, Malte Plidschun, Markus A. Schmidt, and Heinz-Siegfried Kitzerow. “Anchoring and Electro-Optic Switching of Liquid Crystals on Nano-Structured Surfaces Fabricated by Two-Photon Based Nano-Printing.” Optical Materials Express 13, no. 12 (2023). https://doi.org/10.1364/ome.503100. ieee: 'B. Zhang, M. Plidschun, M. A. Schmidt, and H.-S. Kitzerow, “Anchoring and electro-optic switching of liquid crystals on nano-structured surfaces fabricated by two-photon based nano-printing,” Optical Materials Express, vol. 13, no. 12, Art. no. 3467, 2023, doi: 10.1364/ome.503100.' mla: Zhang, Bingru, et al. “Anchoring and Electro-Optic Switching of Liquid Crystals on Nano-Structured Surfaces Fabricated by Two-Photon Based Nano-Printing.” Optical Materials Express, vol. 13, no. 12, 3467, Optica Publishing Group, 2023, doi:10.1364/ome.503100. short: B. Zhang, M. Plidschun, M.A. Schmidt, H.-S. Kitzerow, Optical Materials Express 13 (2023). date_created: 2023-12-13T15:59:37Z date_updated: 2023-12-13T16:06:29Z department: - _id: '313' - _id: '230' - _id: '35' doi: 10.1364/ome.503100 intvolume: ' 13' issue: '12' keyword: - Electronic - Optical and Magnetic Materials language: - iso: eng publication: Optical Materials Express publication_identifier: issn: - 2159-3930 publication_status: published publisher: Optica Publishing Group status: public title: Anchoring and electro-optic switching of liquid crystals on nano-structured surfaces fabricated by two-photon based nano-printing type: journal_article user_id: '254' volume: 13 year: '2023' ... --- _id: '28254' abstract: - lang: eng text: With the rapid advances of functional dielectric metasurfaces and their integration on on-chip nanophotonic devices, the necessity of metasurfaces working in different environments, especially in biological applications, arose. However, the metasurfaces’ performance is tied to the unit cell’s efficiency and ultimately the surrounding environment it was designed for, thus reducing its applicability if exposed to altering refractive index media. Here, we report a method to increase a metasurface’s versatility by covering the high-index metasurface with a low index porous SiO2 film, protecting the metasurface from environmental changes while keeping the working efficiency unchanged. We show, that a covered metasurface retains its functionality even when exposed to fluidic environments. article_type: original author: - first_name: René full_name: Geromel, René last_name: Geromel - first_name: Christian full_name: Weinberger, Christian id: '11848' last_name: Weinberger - first_name: Katja full_name: Brormann, Katja last_name: Brormann - first_name: Michael full_name: Tiemann, Michael id: '23547' last_name: Tiemann orcid: 0000-0003-1711-2722 - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 citation: ama: Geromel R, Weinberger C, Brormann K, Tiemann M, Zentgraf T. Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions. Optical Materials Express. 2022;12(1):13-21. doi:10.1364/ome.444264 apa: Geromel, R., Weinberger, C., Brormann, K., Tiemann, M., & Zentgraf, T. (2022). Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions. Optical Materials Express, 12(1), 13–21. https://doi.org/10.1364/ome.444264 bibtex: '@article{Geromel_Weinberger_Brormann_Tiemann_Zentgraf_2022, title={Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions}, volume={12}, DOI={10.1364/ome.444264}, number={1}, journal={Optical Materials Express}, publisher={Optica}, author={Geromel, René and Weinberger, Christian and Brormann, Katja and Tiemann, Michael and Zentgraf, Thomas}, year={2022}, pages={13–21} }' chicago: 'Geromel, René, Christian Weinberger, Katja Brormann, Michael Tiemann, and Thomas Zentgraf. “Porous SiO2 Coated Dielectric Metasurface with Consistent Performance Independent of Environmental Conditions.” Optical Materials Express 12, no. 1 (2022): 13–21. https://doi.org/10.1364/ome.444264.' ieee: 'R. Geromel, C. Weinberger, K. Brormann, M. Tiemann, and T. Zentgraf, “Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions,” Optical Materials Express, vol. 12, no. 1, pp. 13–21, 2022, doi: 10.1364/ome.444264.' mla: Geromel, René, et al. “Porous SiO2 Coated Dielectric Metasurface with Consistent Performance Independent of Environmental Conditions.” Optical Materials Express, vol. 12, no. 1, Optica, 2022, pp. 13–21, doi:10.1364/ome.444264. short: R. Geromel, C. Weinberger, K. Brormann, M. Tiemann, T. Zentgraf, Optical Materials Express 12 (2022) 13–21. date_created: 2021-12-02T18:47:42Z date_updated: 2023-03-08T08:13:58Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '623' - _id: '2' - _id: '35' - _id: '307' doi: 10.1364/ome.444264 intvolume: ' 12' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://www.osapublishing.org/ome/fulltext.cfm?uri=ome-12-1-13&id=465602 oa: '1' page: 13-21 publication: Optical Materials Express publication_identifier: issn: - 2159-3930 publication_status: published publisher: Optica quality_controlled: '1' status: public title: Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions type: journal_article user_id: '23547' volume: 12 year: '2022' ... --- _id: '22450' abstract: - lang: eng text: We realize and investigate a nonlinear metasurface taking advantage of intersubband transitions in ultranarrow GaN/AlN multi-quantum well heterostructures. Owing to huge band offsets, the structures offer resonant transitions in the telecom window around 1.55 µm. These heterostructures are functionalized with an array of plasmonic antennas featuring cross-polarized resonances at these near-infrared wavelengths and their second harmonic. This kind of nonlinear metasurface allows for substantial second-harmonic generation at normal incidence which is completely absent for an antenna array without the multi-quantum well structure underneath. While the second harmonic is originally radiated only into the plane of the quantum wells, a proper geometrical arrangement of the plasmonic elements permits the redirection of the second-harmonic light to free-space radiation, which is emitted perpendicular to the surface. article_number: '2134' article_type: original author: - first_name: Jan full_name: Mundry, Jan last_name: Mundry - first_name: Florian full_name: Spreyer, Florian last_name: Spreyer - first_name: Valentin full_name: Jmerik, Valentin last_name: Jmerik - first_name: Sergey full_name: Ivanov, Sergey last_name: Ivanov - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 - first_name: Markus full_name: Betz, Markus last_name: Betz citation: ama: Mundry J, Spreyer F, Jmerik V, Ivanov S, Zentgraf T, Betz M. Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays. Optical Materials Express. 2021;11(7). doi:10.1364/ome.426236 apa: Mundry, J., Spreyer, F., Jmerik, V., Ivanov, S., Zentgraf, T., & Betz, M. (2021). Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays. Optical Materials Express, 11(7). https://doi.org/10.1364/ome.426236 bibtex: '@article{Mundry_Spreyer_Jmerik_Ivanov_Zentgraf_Betz_2021, title={Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays}, volume={11}, DOI={10.1364/ome.426236}, number={72134}, journal={Optical Materials Express}, publisher={OSA}, author={Mundry, Jan and Spreyer, Florian and Jmerik, Valentin and Ivanov, Sergey and Zentgraf, Thomas and Betz, Markus}, year={2021} }' chicago: Mundry, Jan, Florian Spreyer, Valentin Jmerik, Sergey Ivanov, Thomas Zentgraf, and Markus Betz. “Nonlinear Metasurface Combining Telecom-Range Intersubband Transitions in GaN/AlN Quantum Wells with Resonant Plasmonic Antenna Arrays.” Optical Materials Express 11, no. 7 (2021). https://doi.org/10.1364/ome.426236. ieee: J. Mundry, F. Spreyer, V. Jmerik, S. Ivanov, T. Zentgraf, and M. Betz, “Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays,” Optical Materials Express, vol. 11, no. 7, 2021. mla: Mundry, Jan, et al. “Nonlinear Metasurface Combining Telecom-Range Intersubband Transitions in GaN/AlN Quantum Wells with Resonant Plasmonic Antenna Arrays.” Optical Materials Express, vol. 11, no. 7, 2134, OSA, 2021, doi:10.1364/ome.426236. short: J. Mundry, F. Spreyer, V. Jmerik, S. Ivanov, T. Zentgraf, M. Betz, Optical Materials Express 11 (2021). date_created: 2021-06-16T05:52:21Z date_updated: 2022-01-06T06:55:33Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '429' doi: 10.1364/ome.426236 intvolume: ' 11' issue: '7' language: - iso: eng main_file_link: - open_access: '1' url: https://www.osapublishing.org/ome/fulltext.cfm?uri=ome-11-7-2134&id=452008 oa: '1' project: - _id: '53' name: TRR 142 - _id: '54' name: TRR 142 - Project Area A - _id: '65' name: TRR 142 - Subproject A8 publication: Optical Materials Express publication_identifier: issn: - 2159-3930 publication_status: published publisher: OSA quality_controlled: '1' status: public title: Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays type: journal_article user_id: '30525' volume: 11 year: '2021' ... --- _id: '9681' article_number: '82' author: - first_name: Martin F. full_name: Volk, Martin F. last_name: Volk - first_name: Christian E. full_name: Rüter, Christian E. last_name: Rüter - first_name: Matteo full_name: Santandrea, Matteo id: '55095' last_name: Santandrea orcid: 0000-0001-5718-358X - first_name: Christof full_name: Eigner, Christof id: '13244' last_name: Eigner orcid: https://orcid.org/0000-0002-5693-3083 - first_name: Laura full_name: Padberg, Laura id: '40300' last_name: Padberg - first_name: Harald full_name: Herrmann, Harald id: '216' last_name: Herrmann - first_name: Christine full_name: Silberhorn, Christine id: '26263' last_name: Silberhorn - first_name: Detlef full_name: Kip, Detlef last_name: Kip citation: ama: Volk MF, Rüter CE, Santandrea M, et al. Fabrication of low-loss Rb-exchanged ridge waveguides in z-cut KTiOPO_4. Optical Materials Express. Published online 2017. doi:10.1364/ome.8.000082 apa: Volk, M. F., Rüter, C. E., Santandrea, M., Eigner, C., Padberg, L., Herrmann, H., Silberhorn, C., & Kip, D. (2017). Fabrication of low-loss Rb-exchanged ridge waveguides in z-cut KTiOPO_4. Optical Materials Express, Article 82. https://doi.org/10.1364/ome.8.000082 bibtex: '@article{Volk_Rüter_Santandrea_Eigner_Padberg_Herrmann_Silberhorn_Kip_2017, title={Fabrication of low-loss Rb-exchanged ridge waveguides in z-cut KTiOPO_4}, DOI={10.1364/ome.8.000082}, number={82}, journal={Optical Materials Express}, author={Volk, Martin F. and Rüter, Christian E. and Santandrea, Matteo and Eigner, Christof and Padberg, Laura and Herrmann, Harald and Silberhorn, Christine and Kip, Detlef}, year={2017} }' chicago: Volk, Martin F., Christian E. Rüter, Matteo Santandrea, Christof Eigner, Laura Padberg, Harald Herrmann, Christine Silberhorn, and Detlef Kip. “Fabrication of Low-Loss Rb-Exchanged Ridge Waveguides in z-Cut KTiOPO_4.” Optical Materials Express, 2017. https://doi.org/10.1364/ome.8.000082. ieee: 'M. F. Volk et al., “Fabrication of low-loss Rb-exchanged ridge waveguides in z-cut KTiOPO_4,” Optical Materials Express, Art. no. 82, 2017, doi: 10.1364/ome.8.000082.' mla: Volk, Martin F., et al. “Fabrication of Low-Loss Rb-Exchanged Ridge Waveguides in z-Cut KTiOPO_4.” Optical Materials Express, 82, 2017, doi:10.1364/ome.8.000082. short: M.F. Volk, C.E. Rüter, M. Santandrea, C. Eigner, L. Padberg, H. Herrmann, C. Silberhorn, D. Kip, Optical Materials Express (2017). date_created: 2019-05-07T14:54:33Z date_updated: 2022-01-06T07:04:18Z department: - _id: '15' - _id: '288' doi: 10.1364/ome.8.000082 language: - iso: eng publication: Optical Materials Express publication_identifier: issn: - 2159-3930 publication_status: published status: public title: Fabrication of low-loss Rb-exchanged ridge waveguides in z-cut KTiOPO_4 type: journal_article user_id: '13244' year: '2017' ...