TY - JOUR A1 - Schaal, Frederik A1 - Rutloh, Michael A1 - Weidenfeld, Susanne A1 - Stumpe, Joachim A1 - Michler, Peter A1 - Pruss, Christof A1 - Osten, Wolfgang T1 - Optically addressed modulator for tunable spatial polarization control JF - Optics express : the international electronic journal of optics N2 - We present an optically addressed non-pixelated spatial light modulator. The system is based on reversible photoalignment of a LC cell using a red light sensitive novel azobenzene photoalignment layer. It is an electrode-free device that manipulates the liquid crystal orientation and consequently the polarization via light without artifacts caused by electrodes. The capability to miniaturize the spatial light modulator allows the integration into a microscope objective. This includes a miniaturized 200 channel optical addressing system based on a VCSEL array and hybrid refractive-diffractive beam shapers. As an application example, the utilization as a microscope objective integrated analog phase contrast modulator is shown. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement Y1 - 2018 U6 - https://doi.org/10.1364/OE.26.028119 SN - 1094-4087 VL - 26 IS - 21 SP - 28119 EP - 28130 PB - Optical Society of America CY - Washington ER - TY - GEN A1 - Schaal, Frederik A1 - Rutloh, Michael A1 - Weidenfeld, Susanne A1 - Stumpe, Joachim A1 - Michler, Peter A1 - Pruss, Christof A1 - Osten, Wolfgang T1 - Optically addressed modulator for tunable spatial polarization control T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - We present an optically addressed non-pixelated spatial light modulator. The system is based on reversible photoalignment of a LC cell using a red light sensitive novel azobenzene photoalignment layer. It is an electrode-free device that manipulates the liquid crystal orientation and consequently the polarization via light without artifacts caused by electrodes. The capability to miniaturize the spatial light modulator allows the integration into a microscope objective. This includes a miniaturized 200 channel optical addressing system based on a VCSEL array and hybrid refractive-diffractive beam shapers. As an application example, the utilization as a microscope objective integrated analog phase contrast modulator is shown. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1001 KW - nematic liquid crystals KW - command surfaces KW - light modulator KW - alignment KW - films KW - polymer Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446263 SN - 1866-8372 IS - 1001 SP - 28119 EP - 28130 ER - TY - JOUR A1 - Stumpe, Joachim A1 - Sakhno, O. A1 - Gritsai, Y. A1 - Rosenhauer, R. A1 - Fischer, Th. A1 - Rutloh, Michael A1 - Schaal, F. A1 - Weidenfeld, S. A1 - Jetter, M. A1 - Michler, P. A1 - Pruss, C. A1 - Osten, W. T1 - Active and passive LC based polarization elements JF - Molecular crystals and liquid crystals N2 - Passive and active polarization elements were created by surface and bulk photo-alignment of LCs, reactive LCs, photo-sensitive LCP and photo-curable monomer/LC composites. The use of different photo-sensitive liquid crystalline materials for the development of highly anisotropic elements with high spatial resolution and stability or, alternatively, fast switch ability will be discussed. Photo-active and voltage tunable polarization and diffraction elements are presented. For active micro-optic application a photo-addressed patterned retarder was created. Electrically switchable diffraction gratings were generated by interference exposure of photo-curable LC composites at room temperature characterized by droplet free morphology. These polarization sensitive diffraction elements are characterized be excellent optical properties and low switching times. KW - electrically switchable gratings. KW - diffractive elements KW - polymer/LC composites KW - switchable retarder KW - polarization gratings KW - Polarization elements Y1 - 2014 U6 - https://doi.org/10.1080/15421406.2014.917503 SN - 1542-1406 SN - 1563-5287 VL - 594 IS - 1 SP - 140 EP - 149 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Shubchynskyy, Volodymyr A1 - Boniecka, Justyna A1 - Schweighofer, Alois A1 - Simulis, Justinas A1 - Kvederaviciute, Kotryna A1 - Stumpe, Michael A1 - Mauch, Felix A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd A1 - Boutrot, Freddy A1 - Zipfel, Cyril A1 - Meskiene, Irute T1 - Protein phosphatase AP2C1 negatively regulates basal resistance and defense responses to Pseudomonas syringae JF - Journal of experimental botany N2 - Mitogen-activated protein kinases (MAPKs) mediate plant immune responses to pathogenic bacteria. However, less is known about the cell autonomous negative regulatory mechanism controlling basal plant immunity. We report the biological role of Arabidopsis thaliana MAPK phosphatase AP2C1 as a negative regulator of plant basal resistance and defense responses to Pseudomonas syringae. AP2C2, a closely related MAPK phosphatase, also negatively controls plant resistance. Loss of AP2C1 leads to enhanced pathogen-induced MAPK activities, increased callose deposition in response to pathogen-associated molecular patterns or to P. syringae pv. tomato (Pto) DC3000, and enhanced resistance to bacterial infection with Pto. We also reveal the impact of AP2C1 on the global transcriptional reprogramming of transcription factors during Pto infection. Importantly, ap2c1 plants show salicylic acid-independent transcriptional reprogramming of several defense genes and enhanced ethylene production in response to Pto. This study pinpoints the specificity of MAPK regulation by the different MAPK phosphatases AP2C1 and MKP1, which control the same MAPK substrates, nevertheless leading to different downstream events. We suggest that precise and specific control of defined MAPKs by MAPK phosphatases during plant challenge with pathogenic bacteria can strongly influence plant resistance. KW - Callose KW - defense genes KW - MAPK KW - MAPK phosphatase KW - PAMP KW - PP2C phosphatase KW - Pseudomonas syringae KW - salicylic acid KW - transcription factors Y1 - 2017 U6 - https://doi.org/10.1093/jxb/erw485 SN - 0022-0957 SN - 1460-2431 VL - 68 IS - 5 SP - 1169 EP - 1183 PB - Oxford Univ. Press CY - Oxford ER -