47510
2019
eng
1090802-1
1090802-7
10908
conferenceobject
SPIE - The international society for optics and photonics
Bellingham, WA, USA
1
--
--
--
X-ray emission during ultrashort pulse laser processing
The industrial use of ultrashort laser pulses has made considerable progress in recent years. The reasons for this lie in the availability of high average powers at pulse repetition rates in the several 100 kHz range. The advantages of using ultrashort laser pulses in terms of processing precision can thus be fully exploited. However, high laser intensities on the workpiece can also lead to the generation of unwanted X-rays. Even if the emitted X-ray dose per pulse is low, the accumulated X-ray dose can become significant for high-repetition-rate laser systems so that X-ray exposure safety limits must be considered. The X-ray emission during ultrashort pulse laser processing was investigated for a pulse duration of 925 fs at 1030 nm wavelength and 400 kHz repetition rate. Industrially relevant materials such as steel,aluminum and glass were treated. Tungsten served as reference. X-ray spectra were recorded, and X-ray dose measurements were performed for laser treatment in air. For laser intensities > 2 × 10^13 W/cm2, X-ray doses exceeding the regulatory exposure limits for members of the public were found. Suitable X-ray protection strategies are proposed.
Proceedings of SPIE - FRONTIERS IN ULTRAFAST OPTICS: BIOMEDICAL, SCIENTIFIC, AND INDUSTRIAL APPLICATIONS XIX
10.1117/12.2516165
0277-786X
1996-756X
978-1-5106-2459-7
SPIE Photonics West
San Francisco, USA
02.02.2019
07.02.2019
04.07.2019
Herbert Legall
Christoph Schwanke
Jörn Bonse
Jörg Krüger
eng
uncontrolled
Laser-induced X-ray emission
eng
uncontrolled
Ultrashort laser material interaction
eng
uncontrolled
Radiation protection
Ingenieurwissenschaften und zugeordnete Tätigkeiten
6 Materialchemie
6.2 Material- und Oberflächentechnologien
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
58358
2023
eng
LiM 2023 - 1
LiM 2023 - 6
conferenceobject
Wissenschaftliche Gesellschaft Lasertechnik und Photonik e.V. (WLT)
0
--
--
--
Unwanted X-ray emission in ultrashort pulse laser processing: From metallic to biological materials
X-rays can be generated as an unwanted side effect during ultrashort pulse laser material processing of technical work pieces and even biological samples with laser intensities above 10^13 W/cm^2. First studies demonstrate the need to address this effect in industrial as well as in medical applications. This secondary hazard should be considered in work safety and risk assessment.
Proceedings of the Lasers in Manufacturing Conference 2023
Lasers in Manufacturing 2023 (LiM 2023)
Munich, Germany
26.06.2023
29.06.2023
publish
false
true
S. Kraft
Katrin Böttcher
Jörn Bonse
J. Schille
U. Löschner
Jörg Krüger
eng
uncontrolled
Ultrashort pulse laser processing
eng
uncontrolled
Laser-induced X-ray emission
eng
uncontrolled
Secondary hazard
Ingenieurwissenschaften und zugeordnete Tätigkeiten
6 Materialchemie
6.2 Material- und Oberflächentechnologien
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
24996
2011
eng
1220
1223
conferenceobject
0
--
--
--
Towards an industrial laser doping process for the selective emitter using phosphoric acid as dopant
Different laser supported approaches have already been realized, proving the great potential of laserdoped selective emitters (LDSE). However, it is challenging to establish a low-cost process by using pulsed laser tools. So far a single-step process only leads to satisfying results utilizing cw-lasers. In this paper we have examined a two-step process to produce laser-doped selective emitters on multicrystalline textured standard silicon photovoltaic wafers (90-Ω/sq-Emitter, SiN-antireflection coating (ARC)). The precise ARC removal by near-infrared fs-laser pulses (30 fs, 800 nm), and the doping of uncoated silicon wafers by ns-laser pulses (8 ns, 532 nm) were systematically investigated. In the fs-experiment, optimum conditions for ARC removal were identified. In the nsexperiments under suitable conditions (melting regime), the phosphorous concentration underneath the wafer surface was significantly increased and the sheet resistance was reduced by nearly a factor of two. Moreover, electrical measurements on fired metallization fingers deposited on the laser processed wafers showed low contact resistances. Hence, wafer conditioning with combined fs-laser- and ns-laser-processes are expected to be a promising technology for producing selective emitters.
26th European photovoltaic solar energy conference and exhibition (Proceedings)
27692
3-936338-27-2
10.4229/26thEUPVSEC2011-2BV.1.2
26th European photovoltaic solar energy conference and exhibition
Hamburg, Germany
05.09.2011
08.09.2011
M. Eberstein
M. Geier
H. Grießmann
U. Partsch
L. Voelkel
R. Böhme
Simone Pentzien
Robert Koter
Guido Mann
Jörn Bonse
Jörg Krüger
eng
uncontrolled
Laser processing
eng
uncontrolled
Doping
eng
uncontrolled
Selective emitter
eng
uncontrolled
Multicrystalline silicon
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
23332
2011
eng
1
7
79250R
7925
conferenceobject
The international society for optics and photonics (SPIE)
0
--
--
--
Time-resolved imaging of bulk a-SiO2 upon various ultrashort excitation sequences
Ultrashort pulses lasers are tools of choice for functionalizing the bulk of transparent materials. In particular, direct photoinscription of simple photonic functions have been demonstrated. Those elementary functions rely on the local refractive index change induced when focusing an ultrashort pulse in the volume of a transparent material. The range of possibilities offered by direct photoinscription is still under investigation. To help understanding, optimizing and assessing the full potential of this method, we developed a time-resolved phase contrast microscopy setup. The imaginary part (absorption) and the real part of the laser-induced complex refractive index can be visualized in the irradiated region. The setup is based on a commercially available phase contrast microscope extended into a pump-probe scheme. The originality of our approach is that the illumination is performed by using a pulsed laser source (i.e. a probe beam). Speckle-related issues are solved by employing adequate sets of diffusers. This laser-microscopy technique has a spatial resolution of 650 nm, and the impulse response is about 300 fs. The laser-induced refractive index changes can be tracked up to milliseconds after the energy deposition. The excitation beam (the pump) is focused with a microscope objective (numerical aperture of 0.45) into the bulk of an a-SiO2 sample. The pump beam can be temporally shaped with a SLM-based pulse shaping unit. This additional degree of flexibility allows for observing different interaction regimes. For instance, bulk material processing with femtosecond and picosecond duration pulses will be studied.
Proceedings of SPIE - Photonics West 2011
25907
10.1117/12.876687
Photonics West 2011
San Francisco, CA, USA
22.01.2011
27.01.2011
A. Mermillod-Blondin
C. Mauclair
A. Rosenfeld
Jörn Bonse
R. Stoian
E. Audouard
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Graue Literatur
45128
2018
eng
35
conferenceobject
Universität Stuttgart, Institut für Strahlwerkzeuge (IFSW)
0
--
--
--
Surface functionalization by laser-induced periodic surface structures (LIPSS)
In this contribution the mechanisms of formation and current applications of LIPSS are reviewed, including the colorization of technical surfaces, the control of surface wetting properties, the mimicry of the natural texture of animal integuments, the tailoring of surface colonization by bacterial biofilms, and the improvement of the tribological performance of nanostructured metal surfaces.
10th Stuttgart Laser Technology Forum 2018, Book of Abstracts
10th Stuttgart Laser Technology Forum 2018
Stuttgart, Germany
05.06.2018
06.06.2018
Jörn Bonse
Sabrina V. Kirner
Nadja Epperlein
Dirk Spaltmann
Jörg Krüger
eng
uncontrolled
Laser-induced periodic surface structures (LIPSS)
eng
uncontrolled
Femtosecond laser ablation
eng
uncontrolled
Surface functionalization
eng
uncontrolled
Wetting
eng
uncontrolled
Tribology
eng
uncontrolled
Biofilms
Angewandte Physik
6 Materialchemie
6.2 Material- und Oberflächentechnologien
9 Komponentensicherheit
Energie
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Graue Literatur
9.5 Tribologie und Verschleißschutz
50070
2019
eng
Paper Nano 404
conferenceobject
Laser Institute of America
0
--
--
--
Surface functionalization by laser-induced periodic surface structures
In recent years, the improved understanding of the formation of laser-induced periodic surface structures (LIPSS) has led to an emerging variety of applications that modify the optical, mechanical and chemical properties of many materials. Such structures strongly depend on the laser beam polarization and are formed usually after irradiation with ultrashort linearly polarized laser pulses. The most accepted explanation for the origin of the structures is based on the interference of the incident laser radiation with electromagnetic surface waves that propagate or scatter at the surface of the irradiated materials. This leads to an intensity modulation that is finally responsible for the selective ablation in the form of parallel structures with periods ranging from hundreds of nanometers up to some micrometers. The versatility when forming such structures is based on the high reproducibility with different wavelength, pulse duration and repetition rate laser sources, customized micro- and nanometric spatial resolutions, and the compatibility with industrially relevant processing speeds when combined with fast scanning devices. In this contribution, we review the latest applications in the rapidly emerging field of surface functionalization through LIPSS, including biomimetic functionalities on fluid transport, control of the wetting properties, specific optical responses in technical materials, improvement of tribological performance on metallic surfaces and bacterial and cell growth for medical devices, among many others.
2019 ICALEO Conference Proceedings
978-1-940168-1-42
38th International Congress on Applications of Lasers & Electro-Optics
Orlando, FL, USA
07.10.2019
10.10.2019
false
true
Camilo Florian
Sabrina V. Kirner
Jörg Krüger
Jörn Bonse
eng
uncontrolled
Laser-induced periodic surface structures (LIPSS)
eng
uncontrolled
Laser processing
eng
uncontrolled
Surface functionalization
eng
uncontrolled
Applications
Ingenieurwissenschaften und zugeordnete Tätigkeiten
Angewandte Physik
6 Materialchemie
6.2 Material- und Oberflächentechnologien
Energie
Material
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Graue Literatur
Nano
21438
2010
eng
1
6
Paper 1230-MM05-03
1230E
conferenceobject
Materials Research Society
0
--
--
--
Short-pulse laser induced transient structure formation and ablation studied with time-resolved coherent XUV-scattering
XUV- and X-ray free-electron-lasers (FEL) combine short wavelength, ultrashort pulse duration, spatial coherence and high intensity. This unique combination of properties opens up new possibilities to study the dynamics of non-reversible phenomena with ultrafast temporal and nano- to atomic-scale spatial resolution. In this contribution we wish to present results of time-resolved experiments performed at the XUV-FEL FLASH (HASYLAB/Hamburg) aimed to investigate the nano-scale structural dynamics of laser-irradiated materials. Thin films and fabricated nano-structures, deposited on Si3N4-membranes, have been excited with ultrashort optical laser pulses. The dynamics of the non-reversible structural evolution of the irradiated samples during laser-induced melting and ablation has been studied in an optical pump - XUV-probe configuration by means of single-shot coherent scattering techniques (i.e. diffraction imaging [1]). In a first set of experiments we investigated the formation of laser induced periodic surface structures (LIPSS) on the surface of thin Si-films (thickness 100 nm). In a simplified view LIPPS are generated as a result of interference between the incident laser pulse and surface scattered waves which leads to a periodically modulated energy deposition. Time-resolved scattering using femtosecond XUV-pulses (with a wavelength of 13.5 nm and 7 nm) allowed us to directly follow LIPSS evolution on an ultrafast time-scale and with better than 40 nm spatial resolution. The observed scattering patterns show almost quantitative agreement with theoretical predictions [2] and reveal that the LIPSS start to form already during the 12 ps pump pulse. In the second set of measurements we studied picosecond and femtosecond laser induced ablation and disintegration of fabricated nano-structures. Correlations of coherent diffraction patterns measured at various time delays to the pattern of the undisturbed object show that order in the structure is progressively lost starting from short length scales. This structural rearrangement progresses at close to the speed of sound in the material. Under certain circumstances (e.g. adequate sampling) it became also possible to reconstruct real-space images of the object as it evolves over time [3]. The possibility of femtosecond single-shot imaging of ultrafast dynamic processes with nanoscale resolution provides yet more details of the physical processes involved. [1] H. N. Chapman et al. Nature Phys. 2, 839 (2006). [2] J. F. Young et al., Phys. Rev. B 27, 1155 (1983). [3] A. Barty et al. Nature Phot. 2, 415 (2008).
Fall meeting of the materials research society 2009 - Symposium MM / Materials research society symposium proceedings
23856
10.1557/PROC-1230-MM05-03
Serientitel: Materials Research Society symposium proceedings – Series title: Materials Research Society symposium proceedings
Sonderstandort: Publica-Schrank
Fall meeting of the materials research society 2009
Boston, MA, USA
2009-11-30
2009-12-04
K. Sokolowski-Tinten
A. Barty
S. Boutet
U. Shymanovich
M. Bogan
S. Marchesini
S. Hau-Riege
N. Stojanovic
Jörn Bonse
R. Tobey
H. Ehrke
A. Cavalleri
S. Duesterer
M. Frank
S. Bajt
J. Schulz
M. Seibert
J. Hajdu
R. Treusch
H. Chapman
eng
uncontrolled
Femtosecond laser ablation
eng
uncontrolled
Laser-induced periodic surface structures
eng
uncontrolled
Time-resolved coherent XUV scattering
eng
uncontrolled
Semiconductor
eng
uncontrolled
Silicon
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
Graue Literatur
22230
2010
deu
373
379
1278
conferenceobject
American Institute of Physics
Melville, NY, USA
1
--
--
--
Short-pulse laser induced transient structure formation and ablation studied with time-resolved coherent XUV-scattering
AIP Conference Proceedings 1278
24739
978-0-7354-0828-9
Serientitel: AIP conference proceedings – Series title: AIP conference proceedings
Sonderstandort: Publica-Schrank
International high-power laser ablation conference
Santa Fe, USA
2010-04-18
2010-04-22
01.11.2010
K. Sokolowski-Tinten
A. Barty
S. Boutet
U. Shymanovich
H. Chapman
M. Bogan
S. Marchesini
S. Hau-Riege
N. Stojanovic
Jörn Bonse
Y. Rosandi
H. M. Urbassek
R. Tobey
H. Ehrke
A. Cavalleri
S. Düsterer
H. Redlin
M. Frank
S. Bajt
J. Schulz
M. Seibert
J. Hajdu
R. Treusch
C. Bostedt
M. Hoener
T. Möller
deu
uncontrolled
Femtosecond laser ablation
deu
uncontrolled
Free electron lasers
deu
uncontrolled
Coherent scattering
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
2865
2003
eng
221
234
5118
conferenceobject
SPIE, the International Society for Optical Engineering
Bellingham, Wash.
0
--
--
--
Scanning force microscopic investigations of the femtosecond pulse laser ablation of indium phosphide in air
Laser ablation of single-crystalline indium phosphide (InP) was performed in air by means of linearly polarized Ti:sapphire femtosecond-pulses (800 nm, 130 fs, 10 Hz). As a result of the first laser pulses, several morphological changes (crater formation, rim formation, ripple structures and cones) were observed. These effects were explored using force modulation microscopy (FMM), a technique based on scanning force microscopy (SFM), allowing the simultaneous imaging of both topography and local stiffness at a high lateral resolution. The first laser pulse induces the formation of a protruding rim (height <20 nm, width ~300 nm) bordering the ablated crater. A Fourier-analysis of the multi-pulse generated topographies reveals the formation of wavelength-sized periodic ripples (modulation depth <100 nm) with an orientation perpendicular to that of the electric field vector of the laser radiation. Besides these morphological alterations, also material modifications were observed in the irradiated regions by means of the FFM technique. Within the ablated craters, local stiffness variations were found revealing an inhomogeneous material composition/structure as a consequence of the femtosecond pulse laser treatment.
Nanotechnology 2003
2858
0-8194-4978-4
http://cat.inist.fr/?aModele=afficheN&cpsidt=15329222
Serientitel: SPIE proceedings series – Series title: SPIE proceedings series
Sonderstandort: Publica-Schrank
Nanotechnology Conference 2003
Maspalomas, Gran Canaria, Spain
2003-05-19
2003-05-21
Jörn Bonse
Martin Munz
Heinz Sturm
eng
uncontrolled
Femtosecond laser irradiation
eng
uncontrolled
Microstructure
eng
uncontrolled
Indium phosphide
eng
uncontrolled
Scanning/atomic force microscopy (SFM/AFM)
eng
uncontrolled
Stiffness
eng
uncontrolled
Laser induced periodic surface structures (LIPSS)
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
34755
2015
eng
47
53
conferenceobject
Curran
Red Hook, NY, USA
International Microelectronics and Packaging Society
0
--
--
--
Requirements on glasses for femtosecond-laser based micro-structuring
In this work, glasses with systematically varied compositions were manufactured and irradiated by single Ti:sapphire fs-laserpulses (800 nm, 120 fs), focused at the surface and into the bulk of the glass materials. The samples were tested for their ablation threshold fluence as well as for structural changes using µ-Raman-spectroscopy. Correlations between the glass composition, the material-ablation on the glass surface and the permanent changes of the refractive index inside the glass volume after the irradiation by fs-laser pulses were obtained. The results show, that the structural modifications found at the surface of the glasses and inside its volume are closely related. However, while the ablation threshold fluence of the glass surface primarily depends on the glass dissociation energy, the permanent refractive index change inside the volume is rather determined by its ability for absorbing the fs-laser pulses and the subsequent relaxation processes. The results of this work provide some guidance on how the glass composition can be varied in order to optimize the fs-laser induced modification of dielectrics.
CICMT 2015 - 11th International conference on ceramic interconnect & ceramic microsystems technologies (Proceedings)
37902
978-1-5108-0456-2
10.4071/CICMT-TA24
11th International Conference on Ceramic Interconnect & Ceramic Microsystems Technologies
Dresden, Germany
20.04.2015
23.04.2015
T. Seuthe
M. Grehn
A. Mermillod-Blondin
Jörn Bonse
M. Eberstein
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")