Study on the Duration of Laser-Induced Thin Film Plasma Flash

The accuracy of judging whether the film is damaged directly affects measurement laser damage threshold. When by traditional plasma flash method, there a problem misjudgment caused failure to distinguish and air flash. In order eliminate misjudgment, two flashes are accurately distinguished difference in duration This paper aims obtain theoretical experimental values (tf) analyze factors affecting it. Firstly, taking single-layer hafnium oxide aluminum thin films as examples, when wavelength incident 1064 nm, diameter focusing spot 0.08 cm, energy 100 mJ, pulse width 10 ns, tf oxide, 542.7 299.6 respectively. Secondly, study was carried out. Through six experiments, following results were obtained: (1) With increase energy, both increases; (2) longer than that film. (3) parameters put into calculation model, good agreement with values. Finally, it found increases width, decreases diameter.