Excimer laser system activation

In photo CVD, the chemical reaction is activated by the action of photons, specifically ultraviolet (UV) radiation, which have sufficient energy to break the chemical bonds in the reactant molecules. In many cases, these molecules have a broad electronic absorption band and they are readily excited by UV radiation. Although UV lamps have been used, more energy can be obtained from UV lasers, such as the excimer lasers, which have photon energy ranging from 3.4 eV (XeF laser) to 6.4 eV (ArF laser). A typical photo-laser CVD system is shown schematically in Fig. 5.14.117]... 

Rossier et al. [80] used UV excimer laser photoablation for changing the surface properties of the plastics and drilling. The authors discussed the method for patterning biomolecules on a polymer along with surface coverage of active antibodies and equilibration time. Besides, a method of designing NCE comprising an on-chip injector, column and electrochemical detector was also discussed. Furthermore, the potential of this disposable device was discussed and compared to classical systems. 

The oxygen-iodine chemical transfer laser, 02( A) + I( / 3/2) 02( 2)+ I( /, /2)> based on the same electronic transition as the iodine photochemical laser, I( 7, /2) I( 3/2). and a few systems operating on pure rotational transitions are among the recent developments in chemical laser research. Other electronic lasers such as the iodine photochemical laser and the large group of excimer lasers are also classified sometimes as chemical lasers. Yet, most chemical laser systems utilize vibrotational transitions, almost exclusively of diatomic molecules. Our discussion will be confined to this type of chemical lasers. To emphasize the nonequilibrium characteristics and the time factor we shall consider only pulsed lasers. We shall not discuss important subjects such as optical properties, gas dynamic factors, and computational methods. As specific guiding examples we shall refer to the well-studied F-l-H2->HF-h H laser and the relatively simple (only one active vibrational band) Cl -I- HBr- HCl -I- Br system. ... 

The active medium of the KrF laser is a mixture of krypton, molecular fluorine F2, and helium or argon as buffer gas. The whole gas system can be operated in a closed cycle where the gas is pumped from a reservoir through the laser channel. In the fast discharge, excited Kr and Ar atoms and ions are formed by electron impact. The excimers are formed by several reactions, for example. 

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