TY - JOUR A1 - Pentzien, Simone A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Krüger, Jörg A1 - Kleber, F. A1 - Hollaus, F. A1 - Diem, M. A1 - Sablatnig, R. T1 - Can modern technologies defeat nazi censorship? KW - Laser cleaning KW - Multispectral imaging KW - Image enhancement KW - Ancient manuscripts KW - Image restoration PY - 2010 SN - 1556-4673 VL - 2 IS - 3, Article 1 SP - 1 EP - 16 PB - Association for Computing Machinery CY - New York, NY, USA AN - OPUS4-25651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pentzien, Simone A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Krüger, Jörg A1 - Kleber, F. A1 - Hollaus, F. A1 - Diem, M. A1 - Sablatnig, R. ED - Park, J.-I. ED - Kim, J. T1 - Can Modern Technologies Defeat Nazi Censorship? N2 - Censorship of parts of written text was and is a common practice in totalitarian regimes. It is used to destroy information not approved by the political power. Recovering the censored text is of interest for historical studies of the text. This paper raises the question, whether a censored postcard from 1942 can be made legible by applying multispectral imaging in combination with laser cleaning. In the fields of art conservation (e.g. color measurements), investigation (e.g. Analysis of underdrawings in paintings), and historical document analysis, multispectral imaging techniques have been applied successfully to give visibility to information hidden to the human eye. The basic principle of laser cleaning is to transfer laser pulse energy to a contamination layer by an absorption process that leads to heating and evaporation of the layer. Partial laser cleaning of postcards is possible; dirt on the surface can be removed and the obscured pictures and writings made visible again. We applied both techniques to the postcard. The text could not be restored since the original ink seems to have suffered severe chemical damage. T2 - ACCV 2012 Workshops, 11th Asian conference on computer vision CY - Daejeon, Korea DA - 05.11.2012 KW - Laser cleaning KW - Multispectral imaging KW - Image restoration KW - Image enhancement PY - 2013 SN - 978-3-642-37483-8 SN - 0302-9743 VL - II IS - LNCS 7729 SP - 13 EP - 24 PB - Springer CY - Berlin Heidelberg AN - OPUS4-28160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Eylers, K. A1 - Teubner, T. A1 - Boeck, T. A1 - Symietz, Christian A1 - Bonse, Jörn A1 - Andree, Stefan A1 - Krüger, Jörg A1 - Heidmann, B. A1 - Schmid, M. A1 - Lux-Steiner, M. T1 - Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing N2 - A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD. KW - Femtosecond laser KW - Physical vapor deposition KW - Indium KW - Molybdenum substrate KW - Microconcentrator solar cell PY - 2016 DO - https://doi.org/10.1063/1.4943794 SN - 0003-6951 VL - 108 IS - 11 SP - 111904-1 EP - 111904-4 AN - OPUS4-35602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz A1 - Krüger, F. T1 - Untersuchung zur Ausbreitung und Minderung von Erschütterungen an Trassen des schienengebundenen Nahverkehrs in Geländeniveau N2 - Prognosen zur Erschütterungsausbreitung und zur Immissionssituation in der Umgebung von Bahntrassen sind wegen der Vielfalt der Einflussfaktoren oft mit erheblichen Unsicherheiten behaftet. Ziel der Arbeit war es, die Bedingungen für die Ausbreitung von Körperschall und Erschütterungen genauer zu erfassen und in ein für Prognosezwecke geeignetes Rechenmodell umzusetzen. Aufbauend auf theoretischen Untersuchungen zum Übertragungsverhalten des Bodens und von Gebäuden wurden Erschütterungsmessungen an Trassen verschiedener Bahnen des Stadtverkehrs Erregerspektren sowie mit besonderen Messverfahren Bodenkennwerte ermittelt. Diese dienen als Grundlage für die Modellrechnungen über die Ausbreitung von Erschütterungen. Durch Kontrollmessungen wurde die Anwendbarkeit des Modells überprüft. Es zeigten sich z.T. gute Übereinstimmungen, jedoch wurde auch die Notwendigkeit einer weiteren Verbesserung deutlich. Die Möglichkeiten der Minderung der Erschütterungen wurden umfassend behandelt. KW - Schienenverkehr KW - Erschütterungen KW - Körperschall KW - Rechenmodell KW - Immissionsminderung KW - Immissionsprognose PY - 1983 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544190 N1 - BMFT-Vorhaben TV 7954 - AP 09 000 VL - Bericht 9 SP - 1 EP - 525 PB - Studiengesellschaft für unterirdische Verkehrsanlagen (STUVA) CY - Köln AN - OPUS4-54419 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andree, Stefan A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Bonse, Jörn A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser pulses for photovoltaic bottom-up strategies N2 - A promising technology in photovoltaics is based on micro-concentrator solar cells, where the photovoltaic active area is realized as an array of sub-millimeter sized cells onto which the incident light is focused via microlenses. This approach allows to increase the cell efficiency and to realize much more compact modules compared to macroscopic concentrator devices. At the same time, expensive raw materials can be saved, which is of interest, for example, with respect to indium in the case of copper-indium-gallium-diselenide (CIGSe) thin film solar cells. Two methods to produce micro-sized precursors of CIGSe absorbers on molybdenum are presented using 30-fs laser pulses at 790 nm wavelength. On the one hand, a multi pulse surface structuring of the molybdenum film or the underlying glass substrate and a subsequent physical vapor deposition were used for a site-selective aggregation of indium droplets. On the other hand, a single pulse laser-induced forward transfer was utilized to selectively deposit combined copper-indium precursor pixels on the molybdenum back contact of the solar cell. Post-processing (selenization, isolation, contacting) of the laser-generated micro-sized precursors results in functional CIGSe solar cells. T2 - 10. Mittweidaer Lasertagung CY - Mittweida, Germany DA - 16.11.2017 KW - Copper indium gallium diselenide (CIGSe) KW - Micro solar cell KW - Femtosecond laser KW - Laser ablation KW - Laser-induced forward transfer (LIFT) PY - 2017 SN - 1437-7624 VL - 2 SP - 1 EP - 4 PB - Hochschule Mittweida CY - Mittweida AN - OPUS4-42988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmid, M. A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Ernst, O. A1 - Andree, Stefan A1 - Bonse, Jörn A1 - Boeck, T. A1 - Krüger, Jörg T1 - Locally grown Cu(In,Ga)Se2 micro islands for concentrator solar cells N2 - Light concentration opens up the path to enhanced material efficiency of solar cells via increased conversion efficiency and decreased material requirement. For true material saving, a fabrication method allowing local growth of high quality absorber material is essential. We present two scalable fs-laser based approaches for bottom-up growth of Cu(In,Ga)Se2 micro islands utilizing either site-controlled assembly of In(,Ga) droplets on laser-patterned substrates during physical vapor deposition, or laser-induced forward transfer of (Cu,In,Ga) layers for local precursor arrangement. The Cu(In,Ga)Se2 absorbers formed after selenization can deliver working solar devices showing efficiency enhancement under light concentration. T2 - SPIE OPTO, 2018 CY - San Francisco, USA DA - 29.01.2018 KW - Chalcopyrite KW - Cu(In,Ga)Se2 KW - Fs-laser patterning KW - Laser-induced forward transfer KW - Micro solar cell PY - 2018 SN - 978-1-5106-1540-3 SN - 0277-786X SN - 1996-756X VL - 10527 SP - 1052707-1 EP - 1052707-9 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-44450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andree, Stefan A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Bonse, Jörn A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Production of precursors for micro-concentrator solar cells by femtosecond laser-induced forward transfer N2 - Single-pulse femtosecond laser-induced forward transfer (LIFT, 30 fs, 790 nm) is used to deposit micron-sized dots of copper and/or indium onto a molybdenum layer on glass. Such systems can serve as precursors for the bottom-up manufacturing of micro-concentrator solar cells based on copper-indium-gallium-diselenide. The influence of the thickness of the copper, indium and combined copper-indium donor layers on the quality of the transferred dots was qualified by scanning electron microscopy, energy-dispersive X-ray analysis, and optical microscopy. The potential for manufacturing of a spatial arrangement adapted to the geometry of micro-lens arrays needed for micro-concentrator solar cells is demonstrated. T2 - EMRS Spring Meeting 2017, Symposium X “New frontiers in laser interaction: from hard coatings to smart materials" CY - Strasbourg, France DA - 22.05.2017 KW - Laser-induced forward transfer (LIFT) KW - Femtosecond laser KW - Micro-concentrator solar cell KW - Copper-indium-gallium-diselenide KW - CIGSe PY - 2017 DO - https://doi.org/10.1007/s00339-017-1282-x SN - 1432-0630 SN - 0947-8396 VL - 123 SP - Article 670, 1 EP - 8 AN - OPUS4-42273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Andree, Stefan A1 - Heidmann, B. A1 - Bonse, Jörn A1 - Eylers, K. A1 - Ernst, O. A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser-assisted fabrication of chalcopyrite micro-concentrator photovoltaics N2 - Micro-concentrator solar cells offer an attractive way to further enhance the efficiency of planar-cell technologies while saving absorber material. Here, two laser-based bottom-up processes for the fabrication of regular arrays of CuInSe2 and Cu(In,Ga)Se2 microabsorber islands are presented, namely one approach based on nucleation and one based on laser-induced forward transfer. Additionally, a procedure for processing these microabsorbers to functioning micro solar cells connected in parallel is demonstrated. The resulting cells show up to 2.9% efficiency and a significant efficiency enhancement under concentrated Illumination. KW - Chalcopyrite KW - Femtosecond laser patterning KW - Laser-induced forward transfer KW - Micro-concentrator solar cell KW - Photovoltaics PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-470026 DO - https://doi.org/10.3762/bjnano.9.281 SN - 2190-4286 VL - 9 SP - 3025 EP - 3038 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-47002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kirner, Sabrina V. A1 - Hermens, U. A1 - Mimidis, A. A1 - Skoulas, E. A1 - Florian, C. A1 - Hischen, F. A1 - Plamadeala, C. A1 - Baumgartner, W. A1 - Winands, K. A1 - Mescheder, H. A1 - Krüger, Jörg A1 - Solis, J. A1 - Siegel, J. A1 - Stratakis, E. A1 - Bonse, Jörn T1 - Mimicking bug-like surface structures and their fluid transport produced by ultrashort laser pulse irradiation of steel N2 - Ultrashort laser pulses with durations in the fs-to-ps range were used for large area surface processing of steel aimed at mimicking the morphology and extraordinary wetting behaviour of bark bugs (Aradidae) found in nature. The processing was performed by scanning the laser beam over the surface of polished flat sample surfaces. A systematic variation of the laser processing parameters (peak fluence and effective number of pulses per spot diameter) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, i.e., LIPSS, grooves, spikes, etc.). Moreover, different laser processing strategies, varying laser wavelength, pulse duration, angle of incidence, irradiation atmosphere, and repetition rates, allowed to achieve a range of morphologies that resemble specific structures found on bark bugs. For identifying the ideal combination of parameters for mimicking bug-like structures, the surfaces were inspected by scanning electron microscopy. In particular, tilted micrometre-sized spikes are the best match for the structure found on bark bugs. Complementary to the morphology study, the wetting behaviour of the surface structures for water and oil was examined in terms of philic/ phobic nature and fluid transport. These results point out a route towards reproducing complex surface structures inspired by nature and their functional response in technologically relevant materials. KW - Biomometics KW - Surface wetting KW - Steel KW - Bug KW - Laser-induced periodic surface structures KW - Fluid transport KW - Femtosecond laser ablation PY - 2017 DO - https://doi.org/10.1007/s00339-017-1317-3 SN - 0947-8396 SN - 1432-0630 VL - 123 IS - 12 SP - 754, 1 EP - 13 AN - OPUS4-42817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Levcenko, S. A1 - Bonse, Jörn A1 - Andree, Stefan A1 - Krüger, Jörg A1 - Unold, T. A1 - Boeck, T. A1 - Lux-Steiner, M. C. A1 - Schmid, M. T1 - Local growth of CuInSe2 micro solar cells for concentrator application N2 - A procedure to fabricate CuInSe2 (CISe) micro-absorbers and solar cells for concentrator applications is presented. The micro-absorbers are developed from indium precursor islands, which are deposited on a molybdenum coated glass substrate (back contact), followed by deposition of copper on top and subsequent selenization as well as selective etching of copper selenides. In order to compare the properties of the locally grown absorbers to those of conventional large area CISe films, we systematically examine the compositional and morphological homogeneity of the micro absorbers and carry out photoluminescence measurements. Preliminary devices for micro-concentrator solar cell applications are fabricated by optimizing the copper to indium ratio and the size of the indium precursor islands. The resulting micro solar cells provide a characteristic I–V curve under standard illumination conditions (1 sun). KW - Micro solar cells KW - Light concentration KW - CuInSe2 KW - Absorber optimization KW - Chalcopyrite PY - 2017 UR - https://www.sciencedirect.com/science/article/pii/S2468606917300953 DO - https://doi.org/10.1016/j.mtener.2017.10.010 SN - 2468-6069 VL - 6 IS - December 2017 SP - 238 EP - 247 PB - Elsevier Ltd. AN - OPUS4-42801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Eylers, K. A1 - Teubner, T. A1 - Schramm, H.-P. A1 - Symietz, Christian A1 - Bonse, Jörn A1 - Andree, Stefan A1 - Heidmann, B. A1 - Schmid, M. A1 - Krüger, Jörg A1 - Boeck, T. T1 - Growth and shape of indium islands on molybdenum at micro-roughened spots created by femtosecond laser pulses N2 - Indium islands on molybdenum coated glass can be grown in ordered arrays by surface structuring using a femtosecond laser. The effect of varying the molybdenum coated glass substrate temperature and the indium deposition rate on island areal density, volume and geometry is investigated and evaluated in a physical vapor deposition (PVD) process. The joined impact of growth conditions and spacing of the femtosecond laser structured spots on the arrangement and morphology of indium islands is demonstrated. The results yield a deeper understanding of the island growth and its precise adjustment to industrial requirements, which is indispensable for a technological application of such structures at a high throughput, for instance as precursors for the preparation of Cu(In,Ga)Se2 micro concentrator solar cells. KW - Indium islands KW - Femtosecond laser patterning KW - Diffusion KW - CIGSe micro solar cells PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0169433216325764 DO - https://doi.org/10.1016/j.apsusc.2016.11.135 SN - 0169-4332 SN - 1873-5584 VL - 418 SP - 548 EP - 553 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-40551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gappenach, C. A1 - Krauß, H.-J. A1 - Krüger, Jörg A1 - Offenhäuser, F. A1 - Pintaske, S. T1 - Auswahl Laserschutzprodukte - eine Handreichung N2 - Wer mit Laserstrahlung zu tun hat, sollte vor allem auf den Schutz seiner Augen achten, denn die Netzhaut ist eines der empfindlichsten Gewebe des menschlichen Körpers. Auch die Hornhaut des Auges kann durch Laserstrahlung gefährdet sein. Sie hat eine Dicke von nur etwa 0,5 mm. Der Schutz der Augen vor Laserstrahlung ist durch verschiedene Maßnahmen möglich. KW - Laserschutz KW - Schutzbrille KW - Justierbrille KW - Abschirmung KW - EN 207 KW - EN 208 KW - EN 12254 PY - 2015 SN - 1432-9778 VL - 3 SP - 40 EP - 45 PB - AT-Fachverl. CY - Fellbach AN - OPUS4-33431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gappenach, C. A1 - Krüger, Jörg A1 - Offenhäuser, F. A1 - Pintaske, S. A1 - Krauß, H.-J. T1 - Selecting laser eye protectors - a helping hand N2 - The European laser safety standards EN 207, EN 208, and EN 12254 each contain an annex B, which serves as a guidance for the selection of products. These annexes are informative only and are therefore not binding. As there are a variety of hazard scenarios, it is not recommended to change these annexes to a normative status, through which they would become mandatory. Instead, it is recommended to allow users to apply their own skills and know-how in selecting appropriate products, justifying where and why they deviate from the guidance in the standards. This paper explains the background on which the guidance for selection in the annexes of the standards is based and shows physically meaningful leeway. KW - European standard KW - Laser safety KW - Personal protective equipment PY - 2015 DO - https://doi.org/10.1515/aot-2015-0043 SN - 2192-8576 SN - 2192-8584 VL - 4 IS - 5-6 SP - 389 EP - 395 PB - De Gruyter CY - Berlin; Boston, Mass. AN - OPUS4-35072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reuther, F. A1 - Krüger, Ralph-Peter A1 - Schulz, Günter A1 - Baehr, G. A1 - Westerwelle, U. A1 - Gruetzner, G. ED - Houlihan, F. M. T1 - Tailored novolak resins for advanced photoresists by a two-step procedure - new insight into the molecular structure by coupling GPC and MALDI-TOF-MS T2 - 17th Annual SPIE Conference on Advances in Resist Technology and Processing CY - Santa Clara, CA, USA DA - 2000-02-28 KW - Novolak KW - Structure KW - Synthesis KW - Gel permeation KW - Chromatography KW - MALDI-TOF-MS PY - 2000 SN - 0-8194-3617-8 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 3999 SP - 464 EP - 471 PB - SPIE CY - Bellingham AN - OPUS4-2171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kautek, Wolfgang A1 - Hertwig, Andreas A1 - Martin, Sven A1 - Krüger, Jörg A1 - Lenzner, Matthias A1 - Spielmann, C. A1 - Lenner, M. A1 - Bunte, J. A1 - Puester, T. A1 - Burmester, T. A1 - Fiedler, A. A1 - Heberer, E. A1 - Brose, M. A1 - Stingl, A. A1 - Kiehl, P. A1 - Hönigsmann, H. A1 - Trautinger, F. A1 - Grabner, G. T1 - Safety in Femtosecond Laser Technology - Recent Results of a European Research Project (406) T2 - International Laser Safety Conference 2003 ; ILSC 2003 CY - Jacksonville, FL, USA DA - 2003-03-10 PY - 2003 SN - 0-912035-38-2 SP - 1(?) EP - 10(?) PB - Laser Institute of America CY - Orlando, Fla. AN - OPUS4-2259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, C. A1 - Krausz, F. ED - Dubowski, J. T1 - Structuring of dielectric and metallic materials with ultrashort laser pulses between 20 fs and 3 ps N2 - Laser-micromachining of barium aluminum borosilicate glass, fused silica and stainless steel has been extended down to a pulse duration of 20 fs generated by a Ti:sapphire laser system at a wavelength of 0.8 micrometer. A systematic study shows that, below 100 fs, an enhanced precision and a substantial decrease of the ablation threshold fluence in comparison to pulse laser processing with pulses in the picosecond and nanosecond range could be achieved. The physical mechanism and the technical relevance of this novel microtechnology is discussed. T2 - Conference CY - San José, CA, USA DA - 1997-02-10 KW - Ablation KW - Laser processing KW - Micromachining KW - Structuring KW - Femtosecond pulse laser KW - Glass KW - Silica KW - Steel PY - 1997 SN - 0-8194-2402-1 DO - https://doi.org/10.1117/12.273740 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 2991 SP - 40 EP - 47 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-11893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, C. A1 - Krausz, F. A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Nanometer precision material ablation and optical breakdown with sub-10 fs pulses T2 - 11th International Conference on Ultrafast Phenomena CY - Garmisch-Partenkirchen, Germany DA - 1998-07-12 PY - 1998 SN - 3-540-65430-5 SN - 0172-6218 N1 - Serientitel: Springer Series in chemical physics – Series title: Springer Series in chemical physics IS - 63 SP - 313 EP - 315 PB - Springer CY - Heidelberg AN - OPUS4-12042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, C. A1 - Krausz, F. A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Optical Damage of Dielectrics down to 5 fs T2 - 17th Conference on Lasers and Electro-Optics (CLEO) CY - Baltimore, MD, USA DA - 1997-05-18 PY - 1997 SN - 1-557-52498-X IS - 11 SP - 218 EP - 219 PB - Optical Society of America CY - Washington, DC AN - OPUS4-12043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Krüger, Jörg A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, Ch. A1 - Krausz, F. T1 - Laser ablation of dielectrics with pulse durations between 20 fs and 3 ps PY - 1996 SN - 0003-6951 SN - 1077-3118 VL - 69 IS - 21 SP - 3146 EP - 3148 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-11496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lenzner, Matthias A1 - Krüger, Jörg A1 - Sartania, S. A1 - Cheng, Z. A1 - Spielmann, Ch. A1 - Mourou, G. A1 - Kautek, Wolfgang A1 - Krausz, F. T1 - Femtosecond Optical Breakdown in Dielectrics N2 - We report measurements of the optical breakdown threshold and ablation depth in dielectrics with different band gaps for laser pulse durations ranging from 5 ps to 5 fs at a carrier wavelength of 780 nm. For tau <100 fs, the dominant channel for free electron generation is found to be either impact or multiphoton ionization (MPI) depending on the size of the band gap. The observed MPI rates are substantially lower than those predicted by the Keldysh theory. We demonstrate that sub-10-fs laser pulses open up the way to reversible nonperturbative nonlinear optics (at intensities greater than 1014 W/cm2 slightly below damage threshold) and to nanometer-precision laser ablation (slightly above threshold) in dielectric materials. PY - 1998 SN - 0031-9007 SN - 1079-7114 VL - 80 IS - 18 SP - 4076 EP - 4079 PB - American Physical Society CY - Ridge, NY AN - OPUS4-11518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rücker, Werner A1 - Krüger, F. A1 - Savidis, S. A1 - Auersch, Lutz ED - Aubram, D. T1 - Ein umfassendes Prognoseprogramm für Erschütterungen T2 - 2. Hans Lorenz Symposium CY - Berlin, Deutschland DA - 2006-10-12 PY - 2006 SN - 3-7983-2024-1 N1 - Serientitel: Veröffentlichungen des Grundbauinstitutes der technischen Universität Berlin – Series title: Veröffentlichungen des Grundbauinstitutes der technischen Universität Berlin IS - 40 SP - 159 EP - 170 PB - TU Berlin CY - Berlin AN - OPUS4-13736 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -