Laser-Matter Interactions: Nanostructures, Fabrication and Characterization (original) (raw)
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2004
Laser-induced technological chemical processes can significantly contribute to the development of new methods for micro treatment of materials and hence to the broadening of the application spectrum of laser microtechnology. In this paper three typical laser-activated chemical technological methods in liquids, gases and solids and their possible applications are presented and discussed: 1) Laser-induced liquid-phase jet-chemical etching of metals. In this method, laser radiation which is guided from a coaxially expanding liquid jet-stream initiates locally on a metal surface a thermochemical etching reaction, which leads to a selective material removal at high resolution (< 1 jim) and quality of the treated surface; 2) Local photon-plasma induced synthesis of thin film coatings. This technological method is based on thermochemical CVD processes taking place in a photon-initiated stationary plasma maintained in the electromagnetic optical field of a high-power cw-C02 laser radiation. This method allows synthesis ofthin-film coatings in the open-air atmosphere without using vacuum or reaction chamber; 3) Laser-induced photochemical modification of the optical properties of polymers. This method is based on the local controllable change of the polymer structure leading to modification of the refractive index in the treated area. By numerous independently adjustable laser radiation parameters, for instance wavelength and irradiation dose, the modification process can be controllably driven in order to generate desired functional properties.
Laser-induced chemical micro-treatment and synthesis of materials
Laser-induced technological chemical processes can significantly contribute to the development of new methods for micro treatment of materials and hence to the broadening of the application spectrum of laser microtech-nology. In this paper three typical laser-activated chemical technological methods in liquids, gases and solids and their possible applications are presented and discussed: First, laser-induced liquid-phase jet-chemical etch-ing of metals. In this method, laser radiation which is guided from a coaxially expanding liquid jet-stream initiates locally on a metal surface a thermochemical etching reaction, which leads to a selective material removal at high resolution (< 1 µm) and quality of the treated surface. Second, local photon-plasma induced synthesis of thin film coatings. This technological method is based on thermochemical CVD processes taking place in a photon-initiated stationary plasma maintained in the electromagnetic optical field of a high-power cw-CO 2 la...
Laser interaction with materials: introduction
Journal of the Optical Society of America B, 2014
Laser-materials interaction is the fascinating nexus where laser physics, optical physics, and materials science intersect. Applications include microdeposition via laser-induced forward transfer of thin films, clean materials processing with femtosecond beams, creating color filters with nanoparticles, generating very high density storage sites on subpicosecond time scales, structuring solar cell surfaces for higher efficiency, making nanostructures that would be impossible by other means, and creating in-volume waveguiding structures using femtosecond laser filaments.
Laser processing and chemistry: applications in nanopatterning, material synthesis and biotechnology
Romanian Reports in …, 2005
This overview reports recent experimental and theoretical investigations on laser processing. Among these are the submicron-and nano-patterning of surfaces by means of both nearfield optical techniques and microlens arrays formed by self-organization processes; the pulsedlaser deposition (PLD) of thin films including organic, inorganic and composite materials, and the modification of material surfaces. The latter field, and in particular the surface modification of polytetrafluoroethylene (PTFE, Teflon), has various different applications in biotechnology and medicine. Many of these results have been achieved during the long-standing collaboration between the groups in Linz and Bucharest.
Handbook of Laser Micro- and Nano-Engineering
The vast field of laser-enabled material synthesis, manufacturing, and processing to a large degree relies on the ability to induce and control a range of thermal processes triggered by the laser energy deposition as well as subsequent transport processes involving electrons and phonons. This chapter provides a review of the fundamental mechanisms, thermodynamic driving forces, and kinetics of thermal processes involved in laser-material interactions, with a particular focus on the far-from-equilibrium conditions characteristic of laser processing with short and ultrashort pulses. The peculiarities of the energy redistribution under conditions of electron-phonon nonequilibrium produced by an ultrashort laser excitation are discussed first and followed by analysis of the effect of dimensionality of the heat transfer at different stages of laser-materials interactions. The generation of strong thermoelastic stresses, which may lead to photomechanical spallation, generation of crystal defects, and activation of surface processes are then outlined, along with the implications of laser-induced stresses for practical applications. The discussion of laser-induced phase transformations starts from a brief review of experimental and computational results revealing the conditions leading to transition between the heterogeneous to homogeneous melting mechanisms. The implications of rapid melting and resolidification on microstructure and surface morphology of laser-processed surfaces are considered, and the conditions leading to chemical homogenization, amorphization, and generation of extreme densities of crystal defects are elaborated. The vaporization, which may take the form of evaporation from the surface or an explosive decomposition of superheated liquid (phase explosion), is discussed as the main process responsible for the material removal from the target, that is, for laser ablation. The mechanisms responsible for the generation of nanoparticles in the course of the phase explosion and through the condensation in the ablation plume are also considered and related to the particle size distributions.
Sadhana-academy Proceedings in Engineering Sciences, 2003
Light amplification by stimulated emission of radiation (laser) is a coherent and monochromatic beam of electromagnetic radiation that can propagate in a straight line with negligible divergence and occur in a wide range of wave-length, energy/power and beam-modes/configurations. As a result, lasers find wide applications in the mundane to the most sophisticated devices, in commercial to purely scientific purposes, and in life-saving as well as life-threatening causes. In the present contribution, we provide an overview of the application of lasers for material processing. The processes covered are broadly divided into four major categories; namely, laser-assisted forming, joining, machining and surface engineering. Apart from briefly introducing the fundamentals of these operations, we present an updated review of the relevant literature to highlight the recent advances and open questions. We begin our discussion with the general applications of lasers, fundamentals of laser-matter interaction and classification of laser material processing. A major part of the discussion focuses on laser surface engineering that has attracted a good deal of attention from the scientific community for its technological significance and scientific challenges. In this regard, a special mention is made about laser surface vitrification or amorphization that remains a very attractive but unaccomplished proposition.
Laser induced modification of surface structures
Applied Surface Science, 2007
The results on surface modification of materials of different structures; morphology, grain sizes, density and porosity by exposure to nanosecond laser light are given. Laser induced changes in their surface characteristics are presented. Surface layers of Si 3 N 4 , SiC dense ceramics and BN graphite and turbostratic pressed powders are studied by scanning electron microscopy to reveal the new nanostructures (nanowires or nanotubes) and new morphologies. A pronounced evolution in structure and grain size of BN graphite powders was demonstrated in laser processing layers. #
Nanofabrication with Pulsed Lasers
Nanoscale Research Letters, 2010
An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser-matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laserassisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.
Laser Interactions in Nanomaterials Synthesis
Springer Series in Materials Science, 2009
Laser interactions with materials have unique advantages to explore the rapid synthesis, processing, and in situ characterization of high quality and novel nanoparticles, nanotubes and nanowires. For example, laser vaporization of solids into background gases provides a wide range of processing conditions for the formation of nanomaterials by both catalyst-free and catalyst-assisted growth processes. Laser interactions with the growing nanomaterials provide remote in situ characterization of their size, structure, and composition with unprecedented temporal resolution. In this article, laser interactions involved in the synthesis of primarily carbon nanostructures are reviewed, including the catalyst-free synthesis of single-walled carbon nanohorns and quantum dots, to the catalyst-assisted growth of single and multi-walled carbon nanotubes.