Near-IR laser ablation of organic polymeric materials

Laser ablation of polymeric materials has become an important area of research due to the number of industrial processes and applications that make use of lasers for the fabrication of commercial goods. Lasers ranging from ultraviolet (UV) to infrared (IR) have been used to ablate polymers for different reasons; however, aspects such as mechanism of ablation or molecular structure correlation is frequently overlooked. Understanding how polymeric materials behave on a molecular level during high energy laser irradiation at different wavelengths is necessary for determining the type of laser and material that is best suited for a given application. Molecular structure alone can give great detail about how a polymer will react upon laser irradiation. Up to this point, much of the work that has been performed regarding the ablation of polymers has been conducted in either UV (193-400 nm) or IR (10.6 mum) wavelengths and generally with pulsed lasers. There exists a lack of data on the ablation of polymeric materials at near-IR wavelengths (i.e. 1 mum). Near-IR lasers have recently become of great importance due to the improved technology with fiber lasers, which offer greater mobility and require less complex optical configuration. This research study has two goals; the first involves comparing literature results of historic polymer laser ablation studies to include UV, near-IR and IR irradiation and correlate results with polymeric structure. The effect of aromaticity, degree of crosslinking and other polymeric characteristics including thermal stability, optical and mechanical properties will be investigated. The second goal involves bridging the gap between UV and far-IR ablation studies and collecting data at near-IR wavelengths (1 mum) on various polymeric materials. Structure correlation and mechanisms of ablation will be examined and compared to previous results.