The Experts below are selected from a list of 16893 Experts worldwide ranked by ideXlab platform
François Courvoisier - One of the best experts on this subject based on the ideXlab platform.
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ultrafast bessel beams advanced tools for Laser Materials Processing
arXiv: Applied Physics, 2018Co-Authors: Razvan Stoian, Rémi Meyer, M K Bhuyan, Guodong Zhang, Guanghua Cheng, François CourvoisierAbstract:Ultrafast Bessel beams demonstrate a significant capacity of structuring transparent Materials with high degree of accuracy and exceptional aspect ratio. The ability to localize energy on the nanometer scale (bypassing the 100 nm milestone) makes them ideal tools for advanced Laser nanoscale Processing on surfaces and in the bulk. This allows to generate and combine micron and nano-sized features into hybrid structures that show novel functionalities. Their high aspect ratio and the accurate location can equally drive an efficient material modification and Processing strategy on large dimensions. We review here the main concepts of generating and using Bessel non-diffractive beams and their remarkable features, discuss general characteristics of their interaction with matter in ablation and material modification regimes, and advocate their use for obtaining hybrid micro and nanoscale structures in two and three dimensions performing complex functions. High throughput applications are indicated. The example list ranges from surface nanostructuring and Laser cutting to ultrafast Laser welding and the fabrication of three dimensional photonic systems embedded in the volume.
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ultrafast bessel beams advanced tools for Laser Materials Processing
Advanced Optical Technologies, 2018Co-Authors: Razvan Stoian, M K Bhuyan, Guodong Zhang, Guanghua Cheng, Remy Meyer, François CourvoisierAbstract:Ultrafast Bessel beams demonstrate a significant capacity of structuring transparent Materials with a high degree of accuracy and exceptional aspect ratio. The ability to localize energy on the nanometer scale (bypassing the 100-nm milestone) makes them ideal tools for advanced Laser nanoscale Processing on surfaces and in the bulk. This allows to generate and combine micron and nano-sized features into hybrid structures that show novel functionalities. Their high aspect ratio and the accurate location can equally drive an efficient material modification and Processing strategy on large dimensions. We review, here, the main concepts of generating and using Bessel non-diffractive beams and their remarkable features, discuss general characteristics of their interaction with matter in ablation and material modification regimes, and advocate their use for obtaining hybrid micro and nanoscale structures in two and three dimensions (2D and 3D) performing complex functions. Highthroughput applications are indicated. The example list ranges from surface nanostructuring and Laser cutting to ultrafast Laser welding and the fabrication of 3D photonic systems embedded in the volume.
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Arbitrary shaping of non-diffracting beams for filamentation and ultrafast Laser Materials Processing (Conference Presentation)
Proceedings of SPIE, 2017Co-Authors: François Courvoisier, Rémi Meyer, Remo Giust, Luc Froehly, Maxime Jacquot, Ismail Ouadghir-idrissi, John Michaël DudleyAbstract:Shaping complex light fields such as nondiffracting beams, provide important novel routes to control Laser Materials Processing. Nondiffracting beams are produced from an interference between waves with an angle kept constant along the propagation direction. These beams are of outmost importance for Laser Materials Processing because they offer invariant light-matter interaction conditions. We have used and developed several families of beams generated with phase and amplitude shaping and we will review their impact for Laser surface Processing and high aspect ratio Laser Processing in the bulk of transparent Materials. Bessel beams and higher order Bessel beams allow for high aspect ratio channel drilling, elongated void creation in the bulk of transparent media, or tubular damage creation. We will also discuss the impact of accelerating beam shaping, ie beams with a curved main intensity lobe, to dice Materials with a curved edge. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 682032-PULSAR).
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Arbitrary shaping of femtosecond non-diffracting beams for filamentation and ultrafast Laser Materials Processing
2017Co-Authors: François Courvoisier, Ismail Ouadghiri Idrissi, Rémi Meyer, Remo Giust, Luc Froehly, Maxime Jacquot, John Michaël DudleyAbstract:Shaping complex light fields such as nondiffracting beams, provide important novel routes to control Laser Materials Processing. Nondiffracting beams are produced from an interference between waves with an angle kept constant along the propagation direction. These beams are of outmost importance for Laser Materials Processing because they offer invariant light-matter interaction conditions. We have used and developed several families of beams generated with phase and amplitude shaping and we will review their impact for Laser surface Processing and high aspect ratio Laser Processing in the bulk of transparent Materials. Bessel beams and higher order Bessel beams allow for high aspect ratio channel drilling, elongated void creation in the bulk of transparent media, or tubular damage creation. We will also discuss the impact of accelerating beam shaping, ie beams with a curved main intensity lobe, to dice Materials with a curved edge. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 682032-PULSAR)
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invited ultrafast Laser micro and nano Processing with nondiffracting and curved beams invited paper for the section hot topics in ultrafast Lasers
Optics and Laser Technology, 2016Co-Authors: François Courvoisier, Razvan Stoian, Arnaud CouaironAbstract:Ultrafast Laser Materials Processing has undergone an important change with the development of non-diffracting beams. These beams enable overcoming many of the difficulties usually encountered with standard Gaussian-beam focusing in Materials. We review the techniques of non-diffracting and accelerating beam shaping that generates lines, tubes or curved segments of focused light on distances that exceed the Gaussian Rayleigh range by several orders of magnitude. We review the benefits and applications of nondiffracting beams for Laser micro- and nano-Processing in the general context of Materials Processing with ultrashort pulses in the filamentation regime. We highlight applications on ultra-high aspect ratio nano-drilling and direct Laser Processing along curves.
Razvan Stoian - One of the best experts on this subject based on the ideXlab platform.
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ultrafast bessel beams advanced tools for Laser Materials Processing
arXiv: Applied Physics, 2018Co-Authors: Razvan Stoian, Rémi Meyer, M K Bhuyan, Guodong Zhang, Guanghua Cheng, François CourvoisierAbstract:Ultrafast Bessel beams demonstrate a significant capacity of structuring transparent Materials with high degree of accuracy and exceptional aspect ratio. The ability to localize energy on the nanometer scale (bypassing the 100 nm milestone) makes them ideal tools for advanced Laser nanoscale Processing on surfaces and in the bulk. This allows to generate and combine micron and nano-sized features into hybrid structures that show novel functionalities. Their high aspect ratio and the accurate location can equally drive an efficient material modification and Processing strategy on large dimensions. We review here the main concepts of generating and using Bessel non-diffractive beams and their remarkable features, discuss general characteristics of their interaction with matter in ablation and material modification regimes, and advocate their use for obtaining hybrid micro and nanoscale structures in two and three dimensions performing complex functions. High throughput applications are indicated. The example list ranges from surface nanostructuring and Laser cutting to ultrafast Laser welding and the fabrication of three dimensional photonic systems embedded in the volume.
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ultrafast bessel beams advanced tools for Laser Materials Processing
Advanced Optical Technologies, 2018Co-Authors: Razvan Stoian, M K Bhuyan, Guodong Zhang, Guanghua Cheng, Remy Meyer, François CourvoisierAbstract:Ultrafast Bessel beams demonstrate a significant capacity of structuring transparent Materials with a high degree of accuracy and exceptional aspect ratio. The ability to localize energy on the nanometer scale (bypassing the 100-nm milestone) makes them ideal tools for advanced Laser nanoscale Processing on surfaces and in the bulk. This allows to generate and combine micron and nano-sized features into hybrid structures that show novel functionalities. Their high aspect ratio and the accurate location can equally drive an efficient material modification and Processing strategy on large dimensions. We review, here, the main concepts of generating and using Bessel non-diffractive beams and their remarkable features, discuss general characteristics of their interaction with matter in ablation and material modification regimes, and advocate their use for obtaining hybrid micro and nanoscale structures in two and three dimensions (2D and 3D) performing complex functions. Highthroughput applications are indicated. The example list ranges from surface nanostructuring and Laser cutting to ultrafast Laser welding and the fabrication of 3D photonic systems embedded in the volume.
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invited ultrafast Laser micro and nano Processing with nondiffracting and curved beams invited paper for the section hot topics in ultrafast Lasers
Optics and Laser Technology, 2016Co-Authors: François Courvoisier, Razvan Stoian, Arnaud CouaironAbstract:Ultrafast Laser Materials Processing has undergone an important change with the development of non-diffracting beams. These beams enable overcoming many of the difficulties usually encountered with standard Gaussian-beam focusing in Materials. We review the techniques of non-diffracting and accelerating beam shaping that generates lines, tubes or curved segments of focused light on distances that exceed the Gaussian Rayleigh range by several orders of magnitude. We review the benefits and applications of nondiffracting beams for Laser micro- and nano-Processing in the general context of Materials Processing with ultrashort pulses in the filamentation regime. We highlight applications on ultra-high aspect ratio nano-drilling and direct Laser Processing along curves.
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Ultrafast Laser micro and nano Processing with nondiffracting and curved beams
Optics and Laser Technology, 2016Co-Authors: François Courvoisier, Razvan Stoian, Arnaud CouaironAbstract:Ultrafast Laser Materials Processing has undergone an important change with the development of non-diffracting beams. These beams enable overcoming many of the difficulties usually encountered with standard Gaussian-beam focusing in Materials. We review the techniques of non-diffracting and accelerating beam shaping that generates lines, tubes or curved segments of focused light on distances that exceed the Gaussian Rayleigh range by several orders of magnitude. We review the benefits and applications of nondiffracting beams for Laser micro- and nano-Processing in the general context of Materials Processing with ultrashort pulses in the filamentation regime. We highlight applications on ultra-high aspect ratio nano-drilling and direct Laser Processing along curves.
Anne Feuer - One of the best experts on this subject based on the ideXlab platform.
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Processing constraints resulting from heat accumulation during pulsed and repetitive Laser Materials Processing
Optics Express, 2017Co-Authors: Rudolf Weber, Thomas Graf, Christian Freitag, Anne Feuer, T V Kononenko, V I KonovAbstract:In any pulsed and repetitive Laser process a part of the absorbed Laser energy is thermalized and stays in the material as residual heat. This residual heat is accumulating from pulse to pulse, continuously increasing the temperature, if the time between two pulses does not allow the material to sufficiently cool down. Controlling this so-called heat accumulation is one of the major challenges for Materials Processing with high average power pulsed Lasers and repetitive Processing. Heat accumulation caused by subsequent pulses (HAP) on the same spot and heat accumulation caused by subsequent scans (HAS) over the same spot can significantly reduce process quality, e.g., when the temperature increase caused by heat accumulation exceeds the melting temperature. In both cases, HAS and HAP, it is of particular interest to know the limiting number of pulses or scans after which the heat accumulation temperature exceeds a critical temperature and a pause has to be introduced. Approximation formulas for the case, where the duration of the heat input is short compared to the time between two subsequent heat inputs are derived in this paper, providing analytical scaling laws for the heat accumulation as a function of the Processing parameters. The validity of these approximations is confirmed for HAP with an example of surface ablation of CrNi-steel and for HAS with multi-scan cutting of carbon fiber reinforced plastics (CFRP), both with a picosecond Laser at an average power of up to 1.1 kW. It is shown that for the important case of 1-dimensional heat flow the limiting number of heat inputs decreases with the inverse of the square of the average Laser power.
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heat accumulation during pulsed Laser Materials Processing erratum
Optics Express, 2014Co-Authors: Rudolf Weber, Thomas Graf, Peter Berger, Volkher Onuseit, Margit Wiedenmann, Christian Freitag, Anne FeuerAbstract:With this erratum we aim to correct a transcription error that occurred in our previous paper: In Eq. (3)a)-(3c), Eq. (5), and Eq. (6) the Greek characters were not converted correctly. The properly formatted formulae are listed below. All other contents, calculations and conclusions of the original paper remain unchanged.
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Heat accumulation during pulsed Laser Materials Processing.
Optics Express, 2014Co-Authors: Rudolf Weber, Thomas Graf, Peter Berger, Volkher Onuseit, Margit Wiedenmann, Christian Freitag, Anne FeuerAbstract:Laser Materials Processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average Laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse Processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting Processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed Laser Materials Processing for a given pulse repetition rate is derived.
Rudolf Weber - One of the best experts on this subject based on the ideXlab platform.
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Processing constraints resulting from heat accumulation during pulsed and repetitive Laser Materials Processing
Optics Express, 2017Co-Authors: Rudolf Weber, Thomas Graf, Christian Freitag, Anne Feuer, T V Kononenko, V I KonovAbstract:In any pulsed and repetitive Laser process a part of the absorbed Laser energy is thermalized and stays in the material as residual heat. This residual heat is accumulating from pulse to pulse, continuously increasing the temperature, if the time between two pulses does not allow the material to sufficiently cool down. Controlling this so-called heat accumulation is one of the major challenges for Materials Processing with high average power pulsed Lasers and repetitive Processing. Heat accumulation caused by subsequent pulses (HAP) on the same spot and heat accumulation caused by subsequent scans (HAS) over the same spot can significantly reduce process quality, e.g., when the temperature increase caused by heat accumulation exceeds the melting temperature. In both cases, HAS and HAP, it is of particular interest to know the limiting number of pulses or scans after which the heat accumulation temperature exceeds a critical temperature and a pause has to be introduced. Approximation formulas for the case, where the duration of the heat input is short compared to the time between two subsequent heat inputs are derived in this paper, providing analytical scaling laws for the heat accumulation as a function of the Processing parameters. The validity of these approximations is confirmed for HAP with an example of surface ablation of CrNi-steel and for HAS with multi-scan cutting of carbon fiber reinforced plastics (CFRP), both with a picosecond Laser at an average power of up to 1.1 kW. It is shown that for the important case of 1-dimensional heat flow the limiting number of heat inputs decreases with the inverse of the square of the average Laser power.
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heat accumulation during pulsed Laser Materials Processing erratum
Optics Express, 2014Co-Authors: Rudolf Weber, Thomas Graf, Peter Berger, Volkher Onuseit, Margit Wiedenmann, Christian Freitag, Anne FeuerAbstract:With this erratum we aim to correct a transcription error that occurred in our previous paper: In Eq. (3)a)-(3c), Eq. (5), and Eq. (6) the Greek characters were not converted correctly. The properly formatted formulae are listed below. All other contents, calculations and conclusions of the original paper remain unchanged.
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Heat accumulation during pulsed Laser Materials Processing.
Optics Express, 2014Co-Authors: Rudolf Weber, Thomas Graf, Peter Berger, Volkher Onuseit, Margit Wiedenmann, Christian Freitag, Anne FeuerAbstract:Laser Materials Processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average Laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse Processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting Processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed Laser Materials Processing for a given pulse repetition rate is derived.
Ya Cheng - One of the best experts on this subject based on the ideXlab platform.
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a tutorial on optics for ultrafast Laser Materials Processing basic microProcessing system to beam shaping and advanced focusing methods
Advanced Optical Technologies, 2012Co-Authors: Koji Sugioka, Ya ChengAbstract:Ultrafast Lasers have excellent characteristics for Materials Processing in terms of precision and quality. This tutorial paper introduces the basic concepts of ultra- fast Laser Materials Processing and the structure and key components of typical ultrafast Laser microProcessing systems. The emphasis is on the pulse-shaping devices and systems for controlling and manipulating the spatial, temporal, and polarization properties of focused femto- second Laser pulses.
