Surface laser

Lykke K R and Kay B D 1990 State-to-state inelastic and reactive molecular beam scattering from surfaces Laser Photoionization and Desorption Surface Analysis Techniquesvo 1208, ed N S Nogar (Bellingham, WA SPIE) p 1218... 

MOLECULAR DESORPTION FROM SOLID SURFACES LASER DIAGNOSTICS AND CHEMICAL DYNAMICS... 

Molecular Desorption from Solid Surfaces Laser Diagncbtics AND Chemical Dynamics 45... 

Activation by high temperature hot filament/hot surfaces, laser heating, arc discharge and arc plasma jets, chemically induced hot gas flames, etc. 

Interfacial Viscosity. In a clean system in which two pure liquids produce an interface, the viscosity of the interface should be the same as the bulk solution viscosity. However, surfactant or impurity adsorption at an interface can cause a resistance to fiow to occur that can be measured as the interfacial shear viscosity. This viscosity is defined as the ratio between the shear stress and the shear rate in the plane of the interface (12), Methods used to make these measurements include a viscous traction surface viscometer (J2), droplet-droplet coalescence (J3), the rotating ring viscometer (14), and surface laser light scattering (9). 

Fig. 14. Growing-in profiles of pyrene excimer fluorescence on various silica surfaces. Laser pulse is also presented. (Reprinted with permission from Langmuir, 2 (1986) 616, our ref. (40), Copyright (1986) American Chemical Society).

Fig. 1. Raman spectra of four waters, HjO, H2 0, D2O, and Di left) as ice at 77 K with a liquid N2 cell (see Fig. 6), 135° backscattering directly off the ice surface, laser power 250 mW, spectral slit width 6 cm and right) as neat liquid at room temperature with a capillary tube, 90° scattering, laser power 250 mW, spectral slit width 10 cm". Exciting radiation (488.0 nm) for all RR spectra was provided by a Coherent Innova 90-6 Ar ion laser. The scattered light was dispersed by a SPEX 1403 double monochromator equipped with 1800 grooves/mm holographic gratings and detected by a cooled Hamamatsu 928 photomultiplier tube under the control of a SPEX DM3000 data station as described elsewhere. ...

Laser surface treatment can be used either below or beyond the ablation threshold of the surface. Laser treatment is more often used below the ablation threshold of the material, thus inducing efficient modification of the surface composition [12, 18]. Various laser parameters, such as the wavelength, the fluence (laser intensity), the nature of the environmental gas, or the pulse number, may be changed in order to modify the characteristics of the treated surface as the treatment induces the formation of polar chemical species (hydroxyls, carboxyls, peroxides, etc.). Therefore, the use of laser treatment below the ablation threshold induces adhesion improvement mainly through thermodynamic and chemical parameters. 

Fig. 10.28 SERS for benzenethiol at roughened Au and Pt surfaces. Laser power at the sample 0.5 mW.

The process time depends on the complexity of the 3D microstructures therefore, it is commonly used for prototyping. An extensive review on stereolithography can be found in Reference 119. The latter method is a subtractive manufacturing process that uses a focused high-intensity laser beam to evaporate the material from the surface. Laser ablation is mostly used to fabricate microchannels in thermosetting polymers such as polyimide due to its physical properties. Microstructures of nanometer scale have been danonstrated, but the surface roughness and properties using laser... 

Rapid Tooling, Fig. 10 Repair of a textured surface, laser generating with powder nozzle (Source Trumpf)... 

Laser ablation, also referred to as laser machining or drilling, is a process in which a laser is used to remove materials from a substrate, thereby creating a patterned surface. Laser drilling is a rapid and accurate means to produce holes in materials. By using pulsed lasers, little heat is transferred to... 

Chemical vapor deposition Deposition of solid material when gaseous reactants encounter a hot surface. Laser assisted CVD employs a hot laser-focus rather than a hot surface. 

A schematic of a modem LIBS system is shown in Figure 7.51. The components required are a high-peak-power Q-switched laser, optics to focus the laser onto the sample surface, laser pulse... 

Bescos B, Orea JM, Urena AG (2000) Laser desorption dynamics of carbendazim on a glass surface. Laser Chem 18(4) 219-237... 

Key words recycling alloys, amorphous alloys, alloy coatings, laser surfacing, laser alloying. 

Light from three different lasers (A, B, and C), each with a different wavelength, was shined onto the same metal surface. Laser A produced no photoelectrons. Lasers B and C both produced photoelectrons, hut the photoelechons produced by laser B had a greater velocity than those produced by laser C. Arrange the lasers in order of increasing wavelength. 

The intense fluorescence of laser-dyes embodied in these thin-film glasses, the simplicity to cast these sol-gel glasses in a multilayered sequence of tailored indices of refraction and the waveguide properties observed in such assemblies imply that such multilayered films may be constructed into a surface-laser. Currently, we are examining these structures as the core of a two dimensional laser and other non-linear optical devices. 

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