Thermophysical and spectral features of laser ablation of polymers

Abstract

The effect of intense laser radiation on polymers depends on many factors; the most important of these factors are the optical properties of the polymer at the emission wavelength and the irradiation mode (continuous or pulsed). In the case of ablation of polytetrafluoroethylene (PTFE) with continuous CO₂ laser radiation at a wavelength of 10.6 μm, the initial target temperature and the state of the target microstructure, which is determined by the polymer monolithization mode, are also influencing factors. An increase in the initial temperature of a PTFE target from room temperature to 683 K provides a 2.8-fold increase in the ablation rate and a significant increase in the fiber fraction yield, the quantitative values of which depend on the polymer synthesis and monolithization modes. A tenfold decrease in the emission wavelength to 1.06 μm leads to a multifold decrease in the ablation efficiency of radiation for all polymers; the multiplicity of change in the ablation rate compared to that on a CO₂ laser depends on the polymer type.