Preliminary investigations of ultrafast intense laser wood processing

Conventional wood machining involves the application of a force to separate chips from the workpiece until the desired workpiece size is achieved. Dep ending on the magnitude of the force applied and the compressive resistance of the wood, the machined surfaces are usually subjected to permanent defo rmation, resulting in crushed and broken wood cells. The introduction of th e CO2 laser as an alternative to traditional wood machining processes faile d to improve surface quality because the wood surface is subjected to heati ng and oxidation, creating a layer of charcoal. In this preliminary investi gation, we report on the application of intense femtosecond Ti-sapphire las er pulses on the surfaces of spruce, oak, and maple samples. The resulting surfaces were distinguishably superior when compared to other existing meth ods of wood machining. The wood surface was not charred or melted and the w ood cells on the cut surface remained virtually undamaged. Various paramete rs of this method of machining, such as cutting depth and kerf width, are c urrently under investigation and the results will be presented in subsequen t papers.