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HF/DF Chemical Lasers
Published in Peter K. Cheo, Handbook of Molecular Lasers, 2018
In a chemical laser, the lasing species are produced via an exothermic chemical reaction that can be initiated via chemical, electric discharge, photolysis, electron beam, or other processes. The various methods of initiation are discussed in several thousand chemical laser papers, which have been published in the scientific literature during the past decade. Each method of initiation produces different operating conditions and should be considered a separate class of laser device. This distinction is used by most chemical laser scientists and is consistent with the popular definition that is emerging from President Reagan’s Strategic Defense Initiative (SDI), commonly referred to as “Star Wars” [1]. Several chemical lasers that have the potential for generating very high power laser beams have been proposed for use in Star Wars. These high-power chemical lasers obtain all their energy from chemical reactions and do not require any supplemental energy source, such as an electric discharge or an electron beam. In this chapter, as in the Star Wars terminology, the terms “high-power chemical” and “chemical lasers” will be used synonymously to define a laser in which the entire active medium is produced via chemical reactions.
Light Sources
Published in Roshan L. Aggarwal, Kambiz Alavi, Introduction to Optical Components, 2018
Roshan L. Aggarwal, Kambiz Alavi
A chemical laser obtains its energy from a chemical reaction. Common examples of chemical lasers are (1) chemical oxygen iodine laser (COIL), (2) hydrogen fluoride laser (2.7–2.9 μm), (3) deuterium fluoride laser (3-6–4.2 μm), and (4) oxygen-iodine laser (1.315 μm). The cw HF laser was first demonstrated in 1969 (Spencer 1969).
Chemical lasers
Published in E R Pike, High-power Gas Lasers, 1975, 2020
A chemical laser is a device in which population inversion and laser output are produced directly from a chemical reaction. The chemical energy stored in the reactants (that is, the fuel and the oxidizer gases) is directly converted to coherent radiation with little or no need for electrical or other energy input.
State-to-state chemical kinetic mechanism for HF chemical lasers
Published in Combustion Theory and Modelling, 2020
Hui Li, Tianliang Zhao, Jiaxu Li, Shuqin Jia, Dongzheng Yang, Ying Huai, Zhigang Sun, Daiqian Xie, Liping Duo, Yuqi Jin
In a HF chemical laser system, every exothermic chemical process may lead to rotational nonequilibrium, which was first evidenced in pulsed initiated HF lasers [5] and in continuous-wave HF chemical lasers [6]. In the review paper [4], the presence of rotational nonequilibrium and two possible types of chemical processes that produce the nonequilibrium distribution were discussed. The first type of chemical process is the pumping reaction of F + H2 and H + F2 that determine the nascent rotational population. A series of experimental and numerical results have been published, and these results have demonstrated that the nascent distribution of the product of HF(υ, j) is far from equilibrium Boltzmann distribution [7–10]. The second type of process that also contributes significantly to rotational nonequilibrium is the collisional energy transfer processes involving HF(υ, j). However, these rotational state-to-state rate coefficients have not been obtained because of the complexity and difficulty of direct measurements. Therefore, most of the rotational nonequilibrium models depend on theoretical prediction and some experience assumptions. In recent year, the HF molecule as a key tracer of molecular hydrogen in diffuse interstellar medium attracts more attention [11]. These processes of the rotational energy transfer of HF(υ, j) + M have been calculated through the development of experimental apparatus and the use of molecular reaction dynamics, for: HF(υ, j) + He [12], HF(υ, j) + H [13], and HF(υ, j) + H2 [14,15]. All the above-mentioned results inspire the search for further understanding of HF chemical laser performance.