Pumping Mechanism for Single Line Fluorine Laser

Abstract

For most of the period over which the atomic fluorine laser has been studied, the principal mechanism of excitation has been in doubt. Originally, it was assumed that the upper level was populated either by direct dissociative excitation of fluorine containing molecules or by dissociation of excimer Her* Through collison with a metastable helium atom. However theoretical models and experiments showed that these channals can not populate the uper level of this system.

In this report different pumping sequences of atomic fluorine laser are discussed. It was found that two different charge transfer reactions are responsible for pumping this system.

At low pressures, the charge transfer from He⁺excites the fluorine, Where at high pressures the upper radiotive levels pumped by charge transfer between He ₂₊ ²⁺ and fluorine ions. The main reason of uncertainty was because of these different nature of pumping mechanism, at lower pressures only the doblet lines are seen while at atmospheric press - ures, The quartet lines are doninant. This new pumping mechanisms suggests the single line operation of this laser which partially was achieved in this research work. The normal excitation of a superradiant fluorine laser results in the uncontroled generation of a group of output lines. Two principal outputs having wavelengths of 745 and 635n.m were selected and amplified. The extraction of all available energy from the excited level throuqh a sinqle line molivated this experiment.