title: Spatial distribution characteristics of plasma plume on attenuation of laser radiation under subatmospheric pressure.
abstract: The attenuation of a laser by plasma plume can be restrained for laser welding under subatmospheric pressure. Based on the experimental obtained spectra, the extinctions of a probe laser under different subatmospheric pressures and the spatial distribution of probe laser extinction were measured. The role of subatmospheric pressure on plasma plume was analyzed. The results show that, with decreasing ambient pressure, the extinction of a probe laser decreases, and the welding penetration depth increases. The maximum attainable value of extinction gets far away from the keyhole in the transversal and vertical directions. The attenuation of a fiber laser is about 10% under normal atmosphere, and it reaches only about 1% when the ambient pressure is reduced to 3 kPa.
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.forename: Xinhua
authors.initials: X
authors.lastname: Tang
authors.forename: Fenggui
authors.initials: F
authors.lastname: Lu
authors.forename: Qintao
authors.initials: Q
authors.lastname: Chen
authors.forename: Haichao
authors.initials: H
authors.lastname: Cui