LIFT investigation in nanosecond regime using high speed visualisation

摘要

We studied the extension of LIFT method to the deposition of Cr thin film in the nanosecond regime. The major objective was to perform high-speed visualisation of the different phenomena involved in LEFT process using a CCD camera. The Cr thin films (40 nm thickness), previously deposited on glass substrates by a conventional technique, were irradiated by a SPECTRA PHYSICS 2ω Nd:YAG laser (λ=532 nm, τ= 7ns, 500mJ/pulse, 10Hz). The dynamics of the plume was monitored using a CCD camera. Photos were taken at different delay times after laser irradiation. The timing of both the laser pulse and the gate opening of the CCD camera was controlled by a programmable pulse generator. For plasma visualisation we have set the gate width at 5 ns.