{ "types" : { "Bookmark" : { "pluralLabel" : "Bookmarks" }, "Publication" : { "pluralLabel" : "Publications" }, "GoldStandardPublication" : { "pluralLabel" : "GoldStandardPublications" }, "GoldStandardBookmark" : { "pluralLabel" : "GoldStandardBookmarks" }, "Tag" : { "pluralLabel" : "Tags" }, "User" : { "pluralLabel" : "Users" }, "Group" : { "pluralLabel" : "Groups" }, "Sphere" : { "pluralLabel" : "Spheres" } }, "properties" : { "count" : { "valueType" : "number" }, "date" : { "valueType" : "date" }, "changeDate" : { "valueType" : "date" }, "url" : { "valueType" : "url" }, "id" : { "valueType" : "url" }, "tags" : { "valueType" : "item" }, "user" : { "valueType" : "item" } }, "items" : [ { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2df4b62a1b577089ca60287aee6fe59e0/ifsw", "tags" : [ "myown","energyspectraldensity","grating","laserinduceddamage" ], "intraHash" : "df4b62a1b577089ca60287aee6fe59e0", "interHash" : "861029160368b4091d3ceba2949ffbb7", "label" : "Comprehensive analysis of laser-induced damage mechanism of resonant waveguide gratings exposed to sub-picosecond pulses", "user" : "ifsw", "description" : "", "date" : "2026-04-20 17:01:53", "changeDate" : "2026-04-20 17:01:53", "count" : 2, "pub-type": "conference", "year": "2026", "url": "", "author": [ "A Boubekraoui","G Mourkioti","J. I. Mackenzie","L Gallais","T Graf","M Abdou Ahmed" ], "authors": [ {"first" : "A", "last" : "Boubekraoui"}, {"first" : "G", "last" : "Mourkioti"}, {"first" : "J. I.", "last" : "Mackenzie"}, {"first" : "L", "last" : "Gallais"}, {"first" : "T", "last" : "Graf"}, {"first" : "M", "last" : "Abdou Ahmed"} ], "abstract": "This study investigates the laser-induced damage mechanisms in resonant waveguide gratings (RWGs) exposed to sub-picosecond laser pulses. The laser-induced damage threshold (LIDT) is shown to depend on pulse number, polarization, spectral properties, and resonance-induced field enhancement. Broadband pulses couple weakly to the guided-mode resonance, leading to lower field intensities and slightly higher LIDT values, while TE-polarized resonant pulses produce strong field enhancements that significantly reduce the threshold, especially under multi-pulse exposure. By incorporating the spectral energy distribution and the weighted squared normalized electric field, the proposed model accurately predicts the RWG\u2019s damage behavior. Experiments on a Ta\u2082O\u2085 single-layer RWG deposited on a microstructured sapphire substrate at an incidence angle of 10.8° revealed LIDT values of 101.5 mJ/cm² at resonance and 580 mJ/cm² off-resonance. The strong agreement between experimental and simulated results confirms the model\u2019s reliability and predictive capability.", "eventtitle" : "SPIE PHOTONICS EUROPE", "venue" : "Strasbourg, France", "eventdate" : "2026-04-12/2026-04-16", "bibtexKey": "a.boubekraoui_2026" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2df4b62a1b577089ca60287aee6fe59e0/ayoub.boubek", "tags" : [ "energyspectraldensity","grating","laserinduceddamage","myown" ], "intraHash" : "df4b62a1b577089ca60287aee6fe59e0", "interHash" : "861029160368b4091d3ceba2949ffbb7", "label" : "Comprehensive analysis of laser-induced damage mechanism of resonant waveguide gratings exposed to sub-picosecond pulses", "user" : "ayoub.boubek", "description" : "", "date" : "2026-04-20 16:58:59", "changeDate" : "2026-04-20 17:01:53", "count" : 2, "pub-type": "conference", "year": "2026", "url": "", "author": [ "A Boubekraoui","G Mourkioti","J. I. Mackenzie","L Gallais","T Graf","M Abdou Ahmed" ], "authors": [ {"first" : "A", "last" : "Boubekraoui"}, {"first" : "G", "last" : "Mourkioti"}, {"first" : "J. I.", "last" : "Mackenzie"}, {"first" : "L", "last" : "Gallais"}, {"first" : "T", "last" : "Graf"}, {"first" : "M", "last" : "Abdou Ahmed"} ], "abstract": "This study investigates the laser-induced damage mechanisms in resonant waveguide gratings (RWGs) exposed to sub-picosecond laser pulses. The laser-induced damage threshold (LIDT) is shown to depend on pulse number, polarization, spectral properties, and resonance-induced field enhancement. Broadband pulses couple weakly to the guided-mode resonance, leading to lower field intensities and slightly higher LIDT values, while TE-polarized resonant pulses produce strong field enhancements that significantly reduce the threshold, especially under multi-pulse exposure. By incorporating the spectral energy distribution and the weighted squared normalized electric field, the proposed model accurately predicts the RWG\u2019s damage behavior. Experiments on a Ta\u2082O\u2085 single-layer RWG deposited on a microstructured sapphire substrate at an incidence angle of 10.8° revealed LIDT values of 101.5 mJ/cm² at resonance and 580 mJ/cm² off-resonance. The strong agreement between experimental and simulated results confirms the model\u2019s reliability and predictive capability.", "eventtitle" : "SPIE PHOTONICS EUROPE", "venue" : "Strasbourg, France", "eventdate" : "2026-04-12/2026-04-16", "bibtexKey": "a.boubekraoui_2026" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2e99e94239099fac3de46aeaaa7d70f7a/ifsw", "tags" : [ "myown","grating","Resonant","Sapphire","Ho:YAG","ThindiskLaser","resonant" ], "intraHash" : "e99e94239099fac3de46aeaaa7d70f7a", "interHash" : "822b9888cea510a337f9d5eb01f6b090", "label" : "Efficient Resonant Waveguide Grating for High-Power Lasers in the 2-µm Wavelength Range", "user" : "ifsw", "description" : "", "date" : "2025-03-04 10:51:45", "changeDate" : "2025-03-04 10:52:35", "count" : 3, "pub-type": "inproceedings", "booktitle": "11th EPS-QEOD Europhoton Conference on Solid-State, Fibre, and Waveguide Coherent Light Sources (EUROPHOTON 2024)","publisher":"EDP Sciences", "year": "2024", "url": "/brokenurl#\thttps://doi.org/10.1051/epjconf/202430702024", "author": [ "Ayoub Boubekraoui","Sergei Tomilov","Mykyta Redkin","Danish Bashir","Georgia Mourkioti","Jacob Mackenzie","Clara J. Saraceno","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Sergei", "last" : "Tomilov"}, {"first" : "Mykyta", "last" : "Redkin"}, {"first" : "Danish", "last" : "Bashir"}, {"first" : "Georgia", "last" : "Mourkioti"}, {"first" : "Jacob", "last" : "Mackenzie"}, {"first" : "Clara J.", "last" : "Saraceno"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "307","number": "02024","pages": "2", "doi" : "10.1051/epjconf/202430702024", "bibtexKey": "boubekraoui2024efficient" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/25a8962500baf709b6b765ef18b022b5a/dbashir", "tags" : [ "Resonant","Sapphire","ThindiskLaser","grating","myown","peer" ], "intraHash" : "5a8962500baf709b6b765ef18b022b5a", "interHash" : "8025a8e8de03ba79348dba41eb69720f", "label" : "Sapphire-based resonant waveguide-grating mirrors: advancing their intra-cavity power density capability", "user" : "dbashir", "description" : "", "date" : "2025-03-04 10:24:13", "changeDate" : "2025-03-04 10:24:13", "count" : 3, "pub-type": "article", "journal": "Applied physics. B, Lasers and optics", "year": "2024", "url": "https://link.springer.com/article/10.1007/s00340-023-08144-2", "author": [ "Danish Bashir","Ayoub Boubekraoui","Georgia Mourkioti","Fangfang Li","Petri Karvinen","Markku Kuittinen","Jacob I. Mackenzie","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Danish", "last" : "Bashir"}, {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Georgia", "last" : "Mourkioti"}, {"first" : "Fangfang", "last" : "Li"}, {"first" : "Petri", "last" : "Karvinen"}, {"first" : "Markku", "last" : "Kuittinen"}, {"first" : "Jacob I.", "last" : "Mackenzie"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "130","number": "4", "language" : "English", "doi" : "10.1007/s00340-023-08144-2", "bibtexKey": "bashir2024sapphirebased" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/25a8962500baf709b6b765ef18b022b5a/ifsw", "tags" : [ "myown","grating","Resonant","peer","Sapphire","ThindiskLaser" ], "intraHash" : "5a8962500baf709b6b765ef18b022b5a", "interHash" : "8025a8e8de03ba79348dba41eb69720f", "label" : "Sapphire-based resonant waveguide-grating mirrors: advancing their intra-cavity power density capability", "user" : "ifsw", "description" : "", "date" : "2025-03-04 10:24:13", "changeDate" : "2025-03-04 10:24:13", "count" : 3, "pub-type": "article", "journal": "Applied physics. B, Lasers and optics", "year": "2024", "url": "https://link.springer.com/article/10.1007/s00340-023-08144-2", "author": [ "Danish Bashir","Ayoub Boubekraoui","Georgia Mourkioti","Fangfang Li","Petri Karvinen","Markku Kuittinen","Jacob I. Mackenzie","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Danish", "last" : "Bashir"}, {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Georgia", "last" : "Mourkioti"}, {"first" : "Fangfang", "last" : "Li"}, {"first" : "Petri", "last" : "Karvinen"}, {"first" : "Markku", "last" : "Kuittinen"}, {"first" : "Jacob I.", "last" : "Mackenzie"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "130","number": "4", "language" : "English", "doi" : "10.1007/s00340-023-08144-2", "bibtexKey": "bashir2024sapphirebased" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/256192fef8f09d3d45ed24304e1bc2d9a/dbashir", "tags" : [ "Ho:YAG","Sapphire","ThindiskLaser","grating","myown","peer","resonant" ], "intraHash" : "56192fef8f09d3d45ed24304e1bc2d9a", "interHash" : "fd3adc97b3dd581ec6205ff43d70f52f", "label" : "Resonant grating for wavelength and polarization selection in high-power lasers emitting in the 2-µm wavelength region", "user" : "dbashir", "description" : "", "date" : "2025-03-03 15:04:29", "changeDate" : "2025-03-03 15:04:29", "count" : 3, "pub-type": "article", "journal": "Applied Physics B", "year": "2025", "url": "https://link.springer.com/article/10.1007/s00340-025-08410-5", "author": [ "Danish Bashir","Georgia Mourkioti","Ayoub Boubekraoui","Sergei Tomilov","Mykyta Redkin","Clara J. Saraceno","Thomas Graf","Jacob I. Mackenzie","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Danish", "last" : "Bashir"}, {"first" : "Georgia", "last" : "Mourkioti"}, {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Sergei", "last" : "Tomilov"}, {"first" : "Mykyta", "last" : "Redkin"}, {"first" : "Clara J.", "last" : "Saraceno"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Jacob I.", "last" : "Mackenzie"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "131","number": "15", "language" : "English", "doi" : "10.1007/s00340-025-08410-5", "bibtexKey": "bashir2025resonant" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/256192fef8f09d3d45ed24304e1bc2d9a/ifsw", "tags" : [ "myown","grating","peer","Sapphire","Ho:YAG","ThindiskLaser","resonant" ], "intraHash" : "56192fef8f09d3d45ed24304e1bc2d9a", "interHash" : "fd3adc97b3dd581ec6205ff43d70f52f", "label" : "Resonant grating for wavelength and polarization selection in high-power lasers emitting in the 2-µm wavelength region", "user" : "ifsw", "description" : "", "date" : "2025-03-03 15:04:29", "changeDate" : "2025-03-03 15:04:29", "count" : 3, "pub-type": "article", "journal": "Applied Physics B", "year": "2025", "url": "https://link.springer.com/article/10.1007/s00340-025-08410-5", "author": [ "Danish Bashir","Georgia Mourkioti","Ayoub Boubekraoui","Sergei Tomilov","Mykyta Redkin","Clara J. Saraceno","Thomas Graf","Jacob I. Mackenzie","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Danish", "last" : "Bashir"}, {"first" : "Georgia", "last" : "Mourkioti"}, {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Sergei", "last" : "Tomilov"}, {"first" : "Mykyta", "last" : "Redkin"}, {"first" : "Clara J.", "last" : "Saraceno"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Jacob I.", "last" : "Mackenzie"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "131","number": "15", "language" : "English", "doi" : "10.1007/s00340-025-08410-5", "bibtexKey": "bashir2025resonant" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/226a42b51f4908ea9dca9ed9efa58a9eb/a.boubekraoui", "tags" : [ "grating","myown","peer" ], "intraHash" : "26a42b51f4908ea9dca9ed9efa58a9eb", "interHash" : "99d45af5e2773b8268b06afb849c847b", "label" : "Sapphire-based resonant waveguide-grating mirrors: advancing their intra-cavity power density capability", "user" : "a.boubekraoui", "description" : "", "date" : "2023-12-08 09:52:00", "changeDate" : "2023-12-08 09:52:00", "count" : 3, "pub-type": "article", "journal": "Applied Physics B", "year": "2023", "url": "https://doi.org/10.1007/s00340-023-08144-2", "author": [ "Danish Bashir","Ayoub Boubekraoui","Georgia Mourkioti","Fangfang Li","Petri Karvinen","Markku Kuittinen","Jacob. I. Mackenzie","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Danish", "last" : "Bashir"}, {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Georgia", "last" : "Mourkioti"}, {"first" : "Fangfang", "last" : "Li"}, {"first" : "Petri", "last" : "Karvinen"}, {"first" : "Markku", "last" : "Kuittinen"}, {"first" : "Jacob. I.", "last" : "Mackenzie"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "130","number": "1","pages": "4","abstract": "We report on the design, fabrication, and implementation of a single-layer resonant waveguide-grating (RWG) mirror on a sapphire substrate. Our goal is to enhance these optics capability to withstand high intra-cavity power densities by exploiting the superior thermal properties of sapphire. The RWG was implemented as an intra-cavity folding mirror in an Yb:YAG thin-disk laser to generate linearly polarized and spectrally stabilized radiation. A linearly polarized output power of 191 W with an optical efficiency of 39\\% was obtained in multi-mode operation. This corresponds to a power density of 52 kW/cm2 on the RWG, for which the increase of its surface temperature was measured to be 12 K, which resulted in a 46-fold reduction of the surface temperature rise dependence on the intra-cavity power density with respect to what has been reported for a RWG on a fused silica substrate. In near fundamental-mode operation, a linearly polarized emission with an output power of 90 W, an optical efficiency of 30\\%, and a spectral bandwidth of 28 pm FWHM was obtained.", "issn" : "1432-0649", "doi" : "10.1007/s00340-023-08144-2", "bibtexKey": "Boubekraoui2023" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/21105676d6caa214a31e39d6d56969daa/ifsw", "tags" : [ "myown","grating","diffraction","laser","peer","from:a.boubekraoui","Thin-disk" ], "intraHash" : "1105676d6caa214a31e39d6d56969daa", "interHash" : "83e4235580a2d04c84dace8c96f28f1f", "label" : "Intra-cavity wavelength multiplexing of high-brightness thin-disk laser beams", "user" : "ifsw", "description" : "", "date" : "2022-07-12 10:26:37", "changeDate" : "2022-07-12 08:26:37", "count" : 2, "pub-type": "article", "journal": "Applied Physics B", "year": "2022", "url": "https://doi.org/10.1007/s00340-022-07836-5", "author": [ "Ayoub Boubekraoui","Frieder Beirow","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Frieder", "last" : "Beirow"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "128","number": "7","pages": "120--","abstract": "We report on the first demonstration of an intra-cavity spectral beam combining of two fundamental-mode laser beams generated by a dual Yb:YAG thin-disk resonator. The two thin-disk lasers (TDLs) were operated at the two slightly different wavelengths of 1028 nm and 1032 nm. A resonant diffraction grating waveguide structure was used as common spectral stabilizer and combiner. An average power exceeding 200 W with close to diffraction-limited beam quality ( $$M^2<1.3$$) was obtained with the presented approach.", "issn" : "14320649", "refid" : "Boubekraoui2022", "doi" : "10.1007/s00340-022-07836-5", "bibtexKey": "boubekraoui2022intracavity" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/21105676d6caa214a31e39d6d56969daa/a.boubekraoui", "tags" : [ "Thin-disk","diffraction","grating","laser","myown","peer" ], "intraHash" : "1105676d6caa214a31e39d6d56969daa", "interHash" : "83e4235580a2d04c84dace8c96f28f1f", "label" : "Intra-cavity wavelength multiplexing of high-brightness thin-disk laser beams", "user" : "a.boubekraoui", "description" : "", "date" : "2022-07-11 18:03:57", "changeDate" : "2022-07-12 08:26:37", "count" : 2, "pub-type": "article", "journal": "Applied Physics B", "year": "2022", "url": "https://doi.org/10.1007/s00340-022-07836-5", "author": [ "Ayoub Boubekraoui","Frieder Beirow","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Ayoub", "last" : "Boubekraoui"}, {"first" : "Frieder", "last" : "Beirow"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "128","number": "7","pages": "120--","abstract": "We report on the first demonstration of an intra-cavity spectral beam combining of two fundamental-mode laser beams generated by a dual Yb:YAG thin-disk resonator. The two thin-disk lasers (TDLs) were operated at the two slightly different wavelengths of 1028 nm and 1032 nm. A resonant diffraction grating waveguide structure was used as common spectral stabilizer and combiner. An average power exceeding 200 W with close to diffraction-limited beam quality ( $$M^2<1.3$$) was obtained with the presented approach.", "issn" : "14320649", "refid" : "Boubekraoui2022", "doi" : "10.1007/s00340-022-07836-5", "bibtexKey": "boubekraoui2022intracavity" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/28369a5b0b9c1d5b9bd78f25cc22c6d13/florianbienert", "tags" : [ "LIL","algorithm","chirp","diffraction","diffraction_grating","grating","interference","interference_lithography","myown","peer","therory" ], "intraHash" : "8369a5b0b9c1d5b9bd78f25cc22c6d13", "interHash" : "503e2f12069fc6f23a499ccd4bb69f64", "label" : "Theoretical investigation on the elimination of the period chirp by deliberate substrate deformations", "user" : "florianbienert", "description" : "", "date" : "2022-06-09 10:04:50", "changeDate" : "2022-06-09 08:04:50", "count" : 3, "pub-type": "article", "journal": "Optics Express","publisher":"Optica Publishing Group", "year": "2022", "url": "https://doi.org/10.1364%2Foe.458636", "author": [ "Florian Bienert","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Florian", "last" : "Bienert"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "30","number": "13","pages": "22410","abstract": "We present a theoretical investigation on the approach of deliberately bending the substrate during the exposure within laser interference lithography to compensate for the period chirp. It is shown that the yet undiscovered function of the surface geometry, necessary to achieve the zero-chirp case (i.e. having a perfectly constant period over the whole substrate) is determined by a first-order differential equation. As the direct analytical solution of this differential equation is difficult, a numerical approach is developed, based on the optimization of pre-defined functions towards the unknown analytical solution of the differential equation by means of a Nelder-Mead simplex algorithm. By applying this method to a concrete example, we show that an off-center placement of the substrate with respect to the point sources is advantageous both in terms of achievable period and substrate curvature and that a fourth-order polynomial can greatly satisfy the differential equation leading to a root-mean-square deviation of only 1.4 pm with respect to the targeted period of 610\u2005nm.", "doi" : "10.1364/oe.458636", "bibtexKey": "Bienert_2022" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/28369a5b0b9c1d5b9bd78f25cc22c6d13/ifsw", "tags" : [ "myown","chirp","diffraction","diffraction_grating","interference_lithography","LIL","from:florianbienert","grating","peer","interference","therory","algorithm" ], "intraHash" : "8369a5b0b9c1d5b9bd78f25cc22c6d13", "interHash" : "503e2f12069fc6f23a499ccd4bb69f64", "label" : "Theoretical investigation on the elimination of the period chirp by deliberate substrate deformations", "user" : "ifsw", "description" : "", "date" : "2022-06-09 10:04:50", "changeDate" : "2022-06-09 08:04:50", "count" : 3, "pub-type": "article", "journal": "Optics Express","publisher":"Optica Publishing Group", "year": "2022", "url": "https://doi.org/10.1364%2Foe.458636", "author": [ "Florian Bienert","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Florian", "last" : "Bienert"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "30","number": "13","pages": "22410","abstract": "We present a theoretical investigation on the approach of deliberately bending the substrate during the exposure within laser interference lithography to compensate for the period chirp. It is shown that the yet undiscovered function of the surface geometry, necessary to achieve the zero-chirp case (i.e. having a perfectly constant period over the whole substrate) is determined by a first-order differential equation. As the direct analytical solution of this differential equation is difficult, a numerical approach is developed, based on the optimization of pre-defined functions towards the unknown analytical solution of the differential equation by means of a Nelder-Mead simplex algorithm. By applying this method to a concrete example, we show that an off-center placement of the substrate with respect to the point sources is advantageous both in terms of achievable period and substrate curvature and that a fourth-order polynomial can greatly satisfy the differential equation leading to a root-mean-square deviation of only 1.4 pm with respect to the targeted period of 610\u2005nm.", "doi" : "10.1364/oe.458636", "bibtexKey": "Bienert_2022" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2c92c0beab91cf22a13ce0cb2209438b6/ifsw", "tags" : [ "chirp","period","Interference","diffraction_grating","Laser_beam","ltihography","interference_lithography","from:florianbienert","ifsw","Diffraction","grating" ], "intraHash" : "c92c0beab91cf22a13ce0cb2209438b6", "interHash" : "1ecc9d05102c7ed5274b48e382dbbf69", "label" : "Comprehensive theoretical analysis of the period chirp in laser interference lithography", "user" : "ifsw", "description" : "", "date" : "2022-03-17 14:03:13", "changeDate" : "2022-03-17 13:03:13", "count" : 2, "pub-type": "article", "journal": "Appl. Opt.","publisher":"OSA", "year": "2022", "url": "http://opg.optica.org/ao/abstract.cfm?URI=ao-61-9-2313", "author": [ "Florian Bienert","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Florian", "last" : "Bienert"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "61","number": "9","pages": "2313--2326","abstract": "We present a theoretical investigation on laser interference lithography used for the exposure of linear gratings. The focus is on the geometry of the arising interference lines on the substrate, in particular on their period and orientation, depending on the illumination geometry as determined by the setup. The common approach with point sources emitting spherical wavefronts is considered for the illumination. Three different cases are discussed, namely the interference between two point sources with either two convex, two concave or mixed, i.e., convex and concave wavefronts. General equations focusing mainly on the calculation of the period and the orientation of the grating lines are derived for each of the three exposure cases considering arbitrarily positioned point sources and arbitrarily shaped substrates. Additionally, the interference of symmetrically positioned point sources illuminating plane substrates is investigated, as these boundary conditions significantly simplify the derived equations.", "doi" : "10.1364/AO.451873", "bibtexKey": "Bienert:22" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2c92c0beab91cf22a13ce0cb2209438b6/florianbienert", "tags" : [ "Diffraction","Interference","Laser_beam","chirp","diffraction_grating","grating","ifsw","interference_lithography","ltihography","period" ], "intraHash" : "c92c0beab91cf22a13ce0cb2209438b6", "interHash" : "1ecc9d05102c7ed5274b48e382dbbf69", "label" : "Comprehensive theoretical analysis of the period chirp in laser interference lithography", "user" : "florianbienert", "description" : "", "date" : "2022-03-17 13:51:15", "changeDate" : "2022-03-17 13:03:13", "count" : 2, "pub-type": "article", "journal": "Appl. Opt.","publisher":"OSA", "year": "2022", "url": "http://opg.optica.org/ao/abstract.cfm?URI=ao-61-9-2313", "author": [ "Florian Bienert","Thomas Graf","Marwan Abdou Ahmed" ], "authors": [ {"first" : "Florian", "last" : "Bienert"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Marwan", "last" : "Abdou Ahmed"} ], "volume": "61","number": "9","pages": "2313--2326","abstract": "We present a theoretical investigation on laser interference lithography used for the exposure of linear gratings. The focus is on the geometry of the arising interference lines on the substrate, in particular on their period and orientation, depending on the illumination geometry as determined by the setup. The common approach with point sources emitting spherical wavefronts is considered for the illumination. Three different cases are discussed, namely the interference between two point sources with either two convex, two concave or mixed, i.e., convex and concave wavefronts. General equations focusing mainly on the calculation of the period and the orientation of the grating lines are derived for each of the three exposure cases considering arbitrarily positioned point sources and arbitrarily shaped substrates. Additionally, the interference of symmetrically positioned point sources illuminating plane substrates is investigated, as these boundary conditions significantly simplify the derived equations.", "doi" : "10.1364/AO.451873", "bibtexKey": "Bienert:22" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2024a899cde4e9763146b17865e1d4c57/tomdietrich", "tags" : [ "UKP","grating","myown","peer","thindisklaser","ultrashort" ], "intraHash" : "024a899cde4e9763146b17865e1d4c57", "interHash" : "3efabec09452487d872ca4fe649e0178", "label" : "Radially polarized passively mode-locked thin-disk laser oscillator emitting sub-picosecond pulses with an average output power exceeding the 100 W level", "user" : "tomdietrich", "description" : "", "date" : "2019-04-18 14:07:53", "changeDate" : "2019-04-18 12:07:53", "count" : 7, "pub-type": "article", "journal": "Optics Express", "year": "2018", "url": "https://doi.org/10.1364/OE.26.004401", "author": [ "Frieder Beirow","Michael Eckerle","Benjamin Dannecker","Tom Dietrich","Marwan Abdou Ahmed","Thomas Graf" ], "authors": [ {"first" : "Frieder", "last" : "Beirow"}, {"first" : "Michael", "last" : "Eckerle"}, {"first" : "Benjamin", "last" : "Dannecker"}, {"first" : "Tom", "last" : "Dietrich"}, {"first" : "Marwan", "last" : "Abdou Ahmed"}, {"first" : "Thomas", "last" : "Graf"} ], "volume": "26","number": "4","pages": "10", "bibtexKey": "noauthororeditor" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2e8c002dc965d152228fc61f9a919b52f/tomdietrich", "tags" : [ "grating","myown","polarization","thindisklaser" ], "intraHash" : "e8c002dc965d152228fc61f9a919b52f", "interHash" : "fe659bb2279b3d5fbf85761928c0f699", "label" : "Investigations on ring-shaped pump beam distributions for\r\nhigh-power thin-disk lasers", "user" : "tomdietrich", "description" : "", "date" : "2019-04-18 13:58:11", "changeDate" : "2019-04-18 11:58:11", "count" : 1, "pub-type": "mastersthesis", "year": "2014", "url": "", "author": [ "Tom Dietrich" ], "authors": [ {"first" : "Tom", "last" : "Dietrich"} ], "number": "15","pages": "82", "bibtexKey": "noauthororeditor" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/269c4352e491d28c6e0b6f4dc334aad7c/ifsw", "tags" : [ "SHG","myown","grating","from:tomdietrich","thindisklaser" ], "intraHash" : "69c4352e491d28c6e0b6f4dc334aad7c", "interHash" : "bbe3404d7ec9aa6835673a4ac63949d2", "label" : "Highly-efficient grating waveguide mirror enabling kW-class intra-cavity frequency-doubled thin-disk laser", "user" : "ifsw", "description" : "", "date" : "2019-04-18 13:43:23", "changeDate" : "2019-04-18 11:43:23", "count" : 3, "pub-type": "inproceedings", "booktitle": "Topical meeting on Diffractive Optics", "year": "2017", "url": "", "author": [ "T. Dietrich","S. Piehler","M. Rumpel","P. Villeval","D. Lupinski"," M.","M. Abdou Ahmed","T. Graf" ], "authors": [ {"first" : "T.", "last" : "Dietrich"}, {"first" : "S.", "last" : "Piehler"}, {"first" : "M.", "last" : "Rumpel"}, {"first" : "P.", "last" : "Villeval"}, {"first" : "D.", "last" : "Lupinski"}, {"first" : "", "last" : "M."}, {"first" : "M.", "last" : "Abdou Ahmed"}, {"first" : "T.", "last" : "Graf"} ], "bibtexKey": "dietrich2017SHGFinn" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2d36bdd0b53757c684d251bea78a0ec84/ifsw", "tags" : [ "SHG","myown","grating","from:tomdietrich","polarization","thindisklaser" ], "intraHash" : "d36bdd0b53757c684d251bea78a0ec84", "interHash" : "f3d9777a0be53451237326a607705cb3", "label" : "A 1.1 kW CW intra-cavity frequency-doubled thin-disk laser", "user" : "ifsw", "description" : "", "date" : "2019-04-18 13:41:21", "changeDate" : "2019-04-18 11:41:21", "count" : 4, "pub-type": "inproceedings", "booktitle": "Advanced Solid State Lasers 2017, Nagoya, Aichi Japan","publisher":"Optical Society of America", "year": "2017", "url": "https://www.osapublishing.org/abstract.cfm?uri=ASSL-2017-ATu6A.1", "author": [ "Tom Dietrich","Stefan Piehler","Martin Rumpel","Phillipe Villeval","Dominique Lupinski","Marwan Abdou Ahmed","Thomas Graf" ], "authors": [ {"first" : "Tom", "last" : "Dietrich"}, {"first" : "Stefan", "last" : "Piehler"}, {"first" : "Martin", "last" : "Rumpel"}, {"first" : "Phillipe", "last" : "Villeval"}, {"first" : "Dominique", "last" : "Lupinski"}, {"first" : "Marwan Abdou", "last" : "Ahmed"}, {"first" : "Thomas", "last" : "Graf"} ], "volume": "OSA Laser Congress 2017 (ASSL,LAC) © OSA 2017","pages": "ATu6A--1", "bibtexKey": "dietrich20171" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2b2918d2cf505e98eae05adcbbc52f270/thomas_graf", "tags" : [ "grating","gwm","myown","peer","polarization","radial","thindisklaser" ], "intraHash" : "b2918d2cf505e98eae05adcbbc52f270", "interHash" : "2faf0a7e98b39887261353b481bff89f", "label" : "Thin-disk oscillator delivering radially polarized beams with up to 980 W of CW output power", "user" : "thomas_graf", "description" : "", "date" : "2018-04-20 12:22:53", "changeDate" : "2018-04-20 10:22:57", "count" : 7, "pub-type": "article", "journal": "Optics Letters", "year": "2018", "url": "", "author": [ "Tom Dietrich","Martin Rumpel","Frieder Beirow","cherry May Mateo","Christof Pruss","Wolfgang Osten","Marwan Abdou Ahmed","Thomas Graf" ], "authors": [ {"first" : "Tom", "last" : "Dietrich"}, {"first" : "Martin", "last" : "Rumpel"}, {"first" : "Frieder", "last" : "Beirow"}, {"first" : "cherry May", "last" : "Mateo"}, {"first" : "Christof", "last" : "Pruss"}, {"first" : "Wolfgang", "last" : "Osten"}, {"first" : "Marwan", "last" : "Abdou Ahmed"}, {"first" : "Thomas", "last" : "Graf"} ], "volume": "43","number": "6","abstract": "We report on the generation of kW-class continuous-wave radially polarized laser radiation in an Yb:LuAG thin-disk laser (TDL). Output powers of up to 980 W were achieved with an optical efficiency of 50.5% with respect to the incident pump power of the TDL. The degree of radial polarization was measured to be 95.5% at maximum output power. This was achieved by the integration of a new generation of broadband, large-area grating-waveguide mirror with unprecedented high polarization discrimination as the end-mirror in the TDL resonator.", "bibtexKey": "dietrich2018thindisk" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2b6f7415dacf2ed4098371dcff510fc75/thomas_graf", "tags" : [ "grating","myown","polarization","radial","thindisklaser" ], "intraHash" : "b6f7415dacf2ed4098371dcff510fc75", "interHash" : "7afab11bd0bcbec5423965458c79fcdf", "label" : "CW thin-disk laser emitting kW-class beams with radial polarization", "user" : "thomas_graf", "description" : "", "date" : "2018-04-20 12:22:53", "changeDate" : "2018-04-20 10:22:57", "count" : 3, "pub-type": "inproceedings", "booktitle": "CLEO/Europe-EQEC 2017", "year": "2017", "url": "", "author": [ "Tom Dietrich","Martin Rumpel","Liwei Fu","Christof Pruss","Wolfgang Osten","Marwan Abdou-Ahmed","Thomas Graf" ], "authors": [ {"first" : "Tom", "last" : "Dietrich"}, {"first" : "Martin", "last" : "Rumpel"}, {"first" : "Liwei", "last" : "Fu"}, {"first" : "Christof", "last" : "Pruss"}, {"first" : "Wolfgang", "last" : "Osten"}, {"first" : "Marwan", "last" : "Abdou-Ahmed"}, {"first" : "Thomas", "last" : "Graf"} ], "pages": "CA--2.1", "bibtexKey": "dietrich2017radial" } ] }