Atmospheric Pressure Plasma-Assisted Laser Ablation of Optical Glasses ab 18.97 € als pdf eBook: Atmosphärendruckplasma-unterstützte Laserablation optischer Gläser. Aus dem Bereich: eBooks, Belletristik, Erzählungen,
Atmospheric Pressure Plasma-Assisted Laser Ablation of Optical Glasses ab 25.99 € als Taschenbuch: Atmosphärendruckplasma-unterstützte Laserablation optischer Gläser. 1. Aufl.. Aus dem Bereich: Bücher, Wissenschaft, Technik,
Atmospheric Pressure Plasma-Assisted Laser Ablation of Optical Glasses ab 25.99 EURO Atmosphärendruckplasma-unterstützte Laserablation optischer Gläser. 1. Aufl.
Atmospheric Pressure Plasma-Assisted Laser Ablation of Optical Glasses ab 18.97 EURO Atmosphärendruckplasma-unterstützte Laserablation optischer Gläser
The organic compounds that emit at different wavelength regions have been selected to study. Fluorescent dyes play an important role for staining and sensoring in analytical chemistry, environmental science, biology and medicine. Some fluorescent dyes are laser active and are used in dye lasers. In recent years the research interests changed from liquid dye lasers to solid state dye lasers.Often organic polymers are used as solid matrices for organic dyes. Semiconducting (conjugated) polymers have properties that make them attractive as the gain material for solid state lasers. Dye lasers utilizing a solid host are very attractive for a wide range of applications. For example, in medicine can use in cardiology for ablation of blood clots, photodynamic therapy for photo-radiation and bio-stimulation, biological field DNA detection and sequencing, remote sensing of atmospheric contaminants, underwater communications, holography, optoelectronic applications.
Ablation means removal of material from the surface of an object by vaporization, chipping, or other erosive processes. The term occurs in space physics associated with atmospheric reentry, in glaciology, medicine, and passive fire protection
In the present work, two different approaches for atmospheric pressure plasma-assisted ablation of optical glasses were investigated. For sequential plasma-assisted ablation, the glasses were plasma pre-treated prior to laser ablation. Here, a hydrogenous process gas was applied in order to initiate a plasma-chemical surface modification. It was shown that relevant optical properties and in particular the transmission characteristics of the investigated glasses were modified as a result of such pre-treatment. Several underlying mechanisms were determined: (i) the formation of suboxide layers close to the glass surface, (ii) the implantation of hydrogen into deeper regions of the glass bulk material and (iii) surface roughening due to the plasma pre-treatment. As a result, an enhanced coupling of incoming laser irradiation during subsequent ablation was achieved. This effect allowed a significant reduction of the laser ablation threshold as well as an improved machining quality, i.e. a higher contour accuracy and a reduced surface roughness of the ablated area.For simultaneous plasma-assisted ablation, the laser beam was guided coaxially to an argon plasma beam in order to benefit from plasmaphysical interactions. Due to an additional energy transfer by the plasma during ablation, the ablation rate was notably increased. It was further shown that the plasma beam used for this simultaneous process effects the smoothing of rough optical glass surfaces.The combination of the investigated approaches thus allows providing a novel integrated plasma-assisted ablation process for the micro structuring of optical devices of high quality.
The fundamental physical processes of mid infrared laser ablation in the context of laser desorption mass spectrometry were investigated. Understanding the mechanisms of infrared laser desorption and ablation can lead to improvements in these techniques and expand their applications. Particles were generated from glycerol irradiated at atmospheric pressure using a tunable infrared laser at wavelengths between 2.6 and 3.8 m. The wavelength dependence of size distributions of ablated particles was measured. In addition to particle sizing, fast photography was used to study the dynamics of mid infrared laser desorption and ablation. The wavelength and energy of the infrared laser can be used to effectively tune the composition of the desorption plume. This ability to control the composition of the plume will be used in the development of IR laser ambient ionization mass spectrometry techniques such as atmospheric pressure matrix-assisted laser desorption ionization (AP-MALDI) and matrix-assisted laser desorption electrospray ionization (MALDESI) where the ability to control material removal is critical to efficient ionization.
After decades of development, laser ablation has become an important technique for a large number of applications such as thin film deposition, nanoparticle synthesis, micromachining, chemical analysis, etc. Experimental and theoretical studies have been conducted to understand the physical mechanisms of the laser ablation processes and their dependence on the laser wavelength, pulse duration, ambient gas and target material. The present work describes and investigates the relative importance of the physical mechanisms influencing the characteristics of aluminum laser-induced plasmas. The general scope of this research encompasses a thorough study of the interplay between the plasma plume dynamics and the ambient gas in which they expand. This is achieved by imaging and analyzing the temporal and spatial evolution the plume in terms of spectral intensity, electron density and excitation temperature within various environments, extending from vacuum to atmospheric pressure (760 Torr), in an inert gas like argon and heluim, as well as in a chemically active gas like nitrogen.