Monitoring of Evolving Laser Induced Periodic Surface Structures

Abstract

Laser induced periodic surface structures (LIPSS) are generated on titanium and silicon nitride surfaces by multiple femtosecond laser pulses. An optical imaging system is used to observe the backscattered light during the patterning process. A characteristic fringe pattern in the backscattered light is observed and evidences the surface modification. Experiments are complemented by finite difference time domain numerical simulations which clearly show that the periodic surface modulation leads to characteristic modulations in the coherently scattered light field. It is proposed that these characteristic fringe pattern can be used as a very fast and low-cost monitor of LIPSS formation formation during the manufacturing process.

Controlling LIPSS formation on Ni surface using near-infrared laser beam and its low-order harmonics

“…where ε r can be chosen according to Drude model to account for the transient dynamics of the material's relative permittivity. The FDTD numerical approach has been successfully able to simulate the experimentally manufactured ripples in shape and period [25][26][27][28].…”