VIS and UV laser ablation of polymers

Abstract

Pulsed laser ablation is well established as a universal tool for surface processing of organic polymer materials. The polymer ablation efficiency of different laser wavelengths, from 355 nm to 532 nm, is studied for short laser pulses, of nanosecond pulse duration. Ablation rates of polymers have been measured by irradiating the polymers using a pulsed Nd:YAG laser. This laser source produced pulses at the second and third harmonic simultaneously at (lambda) equals 532 nm and (lambda) equals 355 nm. Effective ablation was also observed by irradiating the polymer samples with the Raman-shifted Nd:YAG laser, at (lambda) equals 397.1 nm, in order to investigate comparatively the ablation efficiency at different laser settings. For transparent materials, in the corresponding ablation wavelengths and pulse width, the dependence of the ablation rate on the laser spot diameter and the laser energy fluence has been investigated. In general, the polymers used in this work show a more or less pronounced increase of the ablation rate with decreasing spot diameter for the same fluence, especially in the case of visible laser irradiation.