Abstract

Ultrafast laser manufacturing has been taking importance over the years because of the wide field of applications. For instance, the processing enables the generation of specific nano-scales periodic organizations on surfaces. The characteristics of these nanostructures called Laser Induced Periodical Surface Structures (LIPSS or ‘ripples’) depend on the different parameters of the laser pulse such as the polarization [1] or the pulse duration and energy [2]. This can be applied in different issues such as polarization guiding, phase retardation, [1,2] surface functionalization for applications involving wettability and tribology properties [3]. Because of their typical dimensions in the range of the irradiating laser wavelength, these nanostructures are usually observed under Scanning Electron Microscopy, Atomic Force Microscopy or other high resolution characterization set ups. Thus, the characterization step needs additional sample manipulation and does not allow for in situ observation. The possibility for in-situ observation of surface modification under laser irradiation has proven to be an inevitable step to reach thorough control of the laser processing parameters in order to reach the full potential of the technique, especially regarding femtosecond laser processing. For example, in situ optical microscopic measurements of bulk laser induced modifications are decisive in understanding and mastering the laser-matter interaction [4].

© 2015 IEEE