Femtosecond Laser Ablation Of Solid Materials

The book introduces ‘the state of the art' of pulsed laser ablation and its applications. It is based on recent theoretical and experimental studies. The book reaches from the basics to advanced topics of pulsed laser ablation. Theoretical and experimental fundamental phenomena involved in pulsed laser ablation are discussed with respect to material properties, laser wavelength, fluence and intensity regime of the light absorbed linearly or non-linearly in the target material. The energy absorbed by the electrons leads to atom/molecule excitation, ionization and/or direct chemical bond breaking and is also transferred to the lattice leading to material heating and phase transitions. Experimental non-invasive optical methods for analyzing these phenomena in real time are described. Theoretical models for pulsed laser ablation and phase transitions induced by laser beams and laser-vapour/plasma interaction during the plume expansion above the target are also presented. Calculations of the ablation speed and dimensions of the ablated micro- and nano-structures are performed. The validity and required refinement of different models in different experimental conditions is provided. The pulsed laser deposition process which bases on collecting the ablated particles on a surface is analyzed in terms of efficiency and quality of the deposited films as a function of ambient conditions, target material, laser parameters and substrate characteristics. The interaction between the incident laser and the ablation plasma is analyzed with respect to its influence on the structures of the deposited films and its capacity to generate high harmonics and single attosecond pulses which are highly desirable in pump-probe experiments.

This is the first comprehensive treatment of the interaction of femtosecond laser pulses with solids at nonrelativistic intensity. It connects phenomena from the subtle atomic motion on the nanoscale to the generation of extreme pressure and temperature in the interaction zone confined inside a solid. The femtosecond laser-matter interaction has already found numerous applications in industry, medicine, and materials science. However, there is no consensus on the interpretation of related phenomena. With mathematics kept to a minimum, this is a highly engaging and readable treatment for students and researchers in science and engineering. The book avoids complex mathematical formulae, and hence the content is accessible to nontechnical readers. Useful summaries after each chapter provide compressed information for quick estimates of major parameters in planned or performed experiments. The book connects the basic physics of femtosecond laser-solid interactions to a broad range of applications. Throught the text, basic assumptions are derived from the first principles, and new results and ideas are presented. From such analyses, a qualitative and predictive framework for the field emerges, the impact of which on applications is also discussed.

This book focuses on the fundamental concepts and physical and chemical aspects of pulsed laser ablation of solid targets in liquid environments and its applications in the preparation of nanomaterials and fabrication of nanostructures. The areas of focus include basic thermodynamic and kinetic processes of laser ablation in liquids, and its applic

Pulsed laser–based techniques for depositing and processing materials are an important area of modern experimental and theoretical scientific research and development, with promising, challenging opportunities in the fields of nanofabrication and nanostructuring. Understanding the interplay between deposition/processing conditions, laser parameters, as well as material properties and dimensionality is demanding for improved fundamental knowledge and novel applications. This book introduces and discusses the basic principles of pulsed laser–matter interaction, with a focus on its peculiarities and perspectives compared to other conventional techniques and state-of-the-art applications. The book starts with an overview of the growth topics, followed by a discussion of laser–matter interaction depending on laser pulse duration, background conditions, materials, and combination of materials and structures. The information outlines the foundation to introduce examples of laser nanostructuring/processing of materials, pointing out the importance of pulsed laser–based technologies in modern (nano)science. With respect to similar texts and monographs, the book offers a comprehensive review including bottom-up and top-down laser-induced processes for nanoparticles and nanomicrostructure generation. Theoretical models are discussed by correlation with advanced experimental protocols in order to account for the fundamentals and underline physical mechanisms of laser–matter interaction. Reputed, internationally recognized experts in the field have contributed to this book. In particular, this book is suitable for a reader (graduate students as well as postgraduates and more generally researchers) new to the subject of pulsed laser ablation in order to gain physical insight into and advanced knowledge of mechanisms and processes involved in any deposition/processing experiment based on pulsed laser–matter interaction. Since knowledge in the field is given step by step comprehensively, this book serves as a valid introduction to the field as well as a foundation for further specific readings.

Femtosecond laser ablation has interesting characteristics for micromachining, notably non-thermal interaction with materials, high peak intensity, precision and flexibility. In this dissertation, the potential of femtosecond laser ablation for fabrication of biomedical and electronic devices is studied. In a preliminary background discussion, some key literature regarding the basic physics and mechanisms that govern ultrafast laser pulse interaction with conductive materials and dielectric materials are summarized. In the dissertation work, results from systematic experiments were used characterize laser ablation of ITO (Indium Tin Oxide), stainless steel (hot embossing applications), polymers (PMMA, PDMS, PET, and PCL), glass, and fused quartz. Measured parameters and results include ablation threshold, damage threshold, surface roughness, single- and multiple-pulse ablation shapes and ablation efficiency. In addition to solid material, femtosecond laser light interaction with electrospun nano-fiber fiber mesh was analyzed and studied by optical property measurements. Ablation of channels in nano-fiber mesh was studied experimentally. Internal channel fabrication in glass and PMMA polymers was also demonstrated and studied experimentally. In summary, it is concluded that femtosecond laser ablation is a useful process for micromachining of materials to produce microfluidic channels commonly needed in biomedical devices such as micro-molecular magnetic separators and DNA stretching micro arrays. The surface roughness of ablated materials was found to be the primary issue for femtosecond laser fabrication of microfluid channels. Improved surface quality of channels by surface coating with HEMA polymer was demonstrated.

Laser ablation refers to the phenomenon in which a low wavelength and short pulse (ns-fs) duration of laser beam irradiates the surface of a target to induce instant local vaporization of the target material generating a plasma plume consisting of photons, electrons, ions, atoms, molecules, clusters, and liquid or solid particles. This book covers various aspects of using laser ablation phenomenon for material processing including laser ablation applied for the deposition of thin films, for the synthesis of nanomaterials, and for the chemical compositional analysis and surface modification of materials. Through the 18 chapters written by experts from international scientific community, the reader will have access to the most recent research and development findings on laser ablation through original research studies and literature reviews.

Nanostructuring of materials is a task at the heart of many modern disciplines in mechanical engineering, as well as optics, electronics, and the life sciences. This book includes an introduction to the relevant nonlinear optical processes associated with very short laser pulses for the generation of structures far below the classical optical diffraction limit of about 200 nanometers as well as coverage of state-of-the-art technical and biomedical applications. These applications include silicon and glass wafer processing, production of nanowires, laser transfection and cell reprogramming, optical cleaning, surface treatments of implants, nanowires, 3D nanoprinting, STED lithography, friction modification, and integrated optics. The book highlights also the use of modern femtosecond laser microscopes and nanoscopes as novel nanoprocessing tools.

Shortly after the demonstration of the first laser, the most intensely studied theoretical topics dealt with laser-matter interactions. Many experiments were undertaken to clarify the major ablation mechanisms. At the same time, numerous theoretical studies, both analytical and numerical, were proposed to describe these interactions. These studies paved the ways toward the development of numerous laser applications, ranging from laser micro- and nanomachining to material analysis, nanoparticle and nanostructure formation, thin-film deposition, etc. Recently, more and more promising novel fields of laser applications have appeared, including biomedicine, catalysis, photovoltaic cells, etc. This book intends to provide the reader with a comprehensive overview of the current state of the art in laser ablation, from its fundamental mechanisms to novel applications.

This book presents new research related to femtosecond laser ablation, coherent control, electronic and thermal processes, coloring, nanoscale heat transfer, and corneal refractive surgery. With laser-pulse durations of one quadrillionth of a second, femtosecond lasers are poised to change the way research is done in a variety of disciplines in science, engineering and medicine. The ability to remove material with minimal collateral damage may be the most striking feature that has not been matched by any other material processing technologies. With the processing power carried by each pulse entering pettawatts (1015 W) in less than 100 femtoseconds, femtosecond lasers can remove virtually any type of material in a few picoseconds while confining the process zone to within tens of nanometers. The result is clean cuts, strong welds, and precision destruction of small targets such as cancer cells with no injury to surrounding materials.