VUV laser ablation of polymers

Chemical and Spectroscopic Aspects of Polymer Ablation: Special Features and Novel Directions

“…363 Existing models for VUV photochemical ablation have not yet been applied to these data. 364 The experimental data on VUV polymer ablation strongly support the operation of photochemical ablation processes. Systematic studies of the ablation products and their temporal evolution and energies are required to determine the role of photothermal processes, if any.…”

“…The extremely low threshold fluences and the ablation rates (much lower than the thermal diffusion lengths of 56 nm for PMMA and 76 nm for PTFE) argue strongly for predominantly photochemical ablation . Existing models for VUV photochemical ablation have not yet been applied to these data …”

The effect of water content on the 193 nm excimer laser ablation

“…A later comprehensive study has shown with large molecular structures such as PMMA or collagen the photochemical main‐chain scission is relevant only to the more powerful 10 eV photon energy of the VUV laser ablation 18 . Given the assumption that the photo­chemical ablation is a layer by layer ablation process and the main molecular chains have to be broken into small fragments to leave the material surface it could be postulated that the molecular structure of the dry material used in this experiment is more difficult to fragment after ablation with the 193 nm excimer laser than the wet material 19 . This result has both surgical and industrial applications.…”

Effect of 193 and 157 nm laser light illumination on the surface properties of TMOS–NiCl2sol–gel derived material

“…The parent molecule breaks up into small fragments, atomic, diatomic or triatomic, that are ejected from the substrate at supersonic speed [3]. The dissociation processes from the excited electronic states populated by the absorption of laser photons in the UV region (248 and 193 nm) coexist with relaxation processes that convert part of the photons' energy to thermal energy [26,27]. Consequently different patterns of dissociation are taking place at this wavelength region due to simultaneous photochemical and thermal effects.…”