Study on ablation of Ni film by ultrashort laser pulse-train

Micromaching by ultrashort laser pulse-train can effectively improve femtosecond laser ablation of metal, which are important both theoretically and practically in micro/nano-laser fabrication applications. In order to study the effect of separation of pulse on the accuracy of laser ablation, the phenomena and process of laser ablation with different separation of pulse train were studied in detail by combining the molecular dynamic simulation and two-temperature model, the electron and lattice temperatures of the layers next to dynamic film surfaces and the snapshots of nickel thin films irradiated by the femtosecond laser pulse trains were obtained. The result is that,within a certain range, as the increase of the separation of pulse, femtosecond pulse train laser ablation of Ni films can apparently cause more flat ablation plane, slower initial melting speed, smaller and more uniform nanoparticles, smaller ablation ratio,which can effectively improve femtosecond laser ablation of metal.