Abstract
By means of 157 nm VUV short-wavelength laser-irradiation the wood layer of damaged cells near the surface as well as deeper wood regions can be removed. As this is a non-thermal laser ablation-process, oxidation of the wood surface exposed to 157 nm under N2-atmosphere is avoided even with high power densities. By applying a mechanical pre-treatment process the wood structure is compressed and can then be removed with almost no damage. Four types of wood - spruce, pine, beech and oak - were ablated in all three main cutting directions prescribed for an anisotropic material such as wood. Several microscopic techniques were used. To measure the ablation depth LSM was applied. The surface roughness as well as the quality of the laser ablation was determined by using LV-SEM. CAM was used to measure the contact angle and thereby calculate the surface energy. Ablation can be carried out regardless of the cutting direction used to obtain clean and open surfaces free of artefacts.