Atmospheric thermal lens induced by high-power CO2 laserbeams in laser materials processing

摘要

The atmospheric thermal lens induced by high-power CO2nlaser beams in laser materials processing and its influence on beamnpropagation and focus are studied in this paper. It is found innexperiments that the atmospheric thermal lens is generated when the airnin the beam propagation path is stationary. But it can be eliminated bynblowing air with a certain pressure into the beam's guidance system.nAlso, the behavior of the beam's propagation under the case of thenthermal lens deviates from Gaussian theory. This deviation is calculatednby the linear and nonlinear models of the atmospheric thermal lens undernthe conditions of a large beam diameter and high power intensity. Innaddition, the influence of the thermal lens on the beam's focus size andnposition is also discussed in this paper