Product Code: ICAL09_206

Texturing Structures of Ti Films by Multiple Femtosecond Laser Pulses
Authors:
Yongguang Huang, College of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Shibing Liu, College of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Presented at ICALEO 2009

Femtosecond laser texturing has proved to be a particularly powerful method for creating a wide variety of surface structures on the metal films, such as a hollow microbump-nanojet sturcture and disk-column-nanodroplet structure on the gold films. The process of femtosecond laser texturing does not rely on material removal, but on hydrodynamic flow produced by inhomogeneous heating and film deformation. Femtosecond laser texturing the metal films demonstrates different behaviors depending on films property such as electron-phone coupling, electron thermal diffusion parameters and film thickness. Recent works have demonstrated nano- and microtexturing of surface structures by single femtosecond laser. Under multi-pulse femtosecond laser irradiation, however, there might exhibit new structures on metal films. In this work, we concentrated on the surface structures of the Ti films by cumulative femtosecond pulses texturing. With increasing laser average power, the pits structure, the bump structure and the crown structure were induced in order by cumulative pulses with the pulse energy of 0.2nJ/pulse to 2nJ/pulse from a femtosecond oscillator. These structures showed large differences from the texturing structures on the gold film by single femtosecond laser. Moreover, the material melt dynamics played different roles in single pulse and cumulative pulses texturing metal films.