Femtosecond Laser Ablation for Mesoscale Specimen Evaluation

Focused ion beam machining revolutionized the way samples are studied in materials science. The introduction of this tool enabled researchers to break into new frontiers of research. While this method focused on the nanometer length scale, the mesoscale manufacturing of samples has not seen such advances. It remains a challenge to manufacture sample geometries too large for focused ion beam milling yet too small for conventional machining. Femtosecond laser ablation opens this length scale of sample space and allows the fabrication of numerous useful geometries. This paper outlines a state-of-the-art femtosecond laser machining system that can be used for rapid, micro- and mesoscale sample preparation. To illustrate the utility of this system, stress-strain data are presented for single-crystal Cu micropillars and three microscale tensile test specimens prepared from physical-vapor-deposited Cu and Ni foils.