Study On Technology Of Nanomachining With Femtosecond Laser

Nanomaterial, short for nano microcrystal material, is origin from solid material,and is considered to be the most promising mew material in 21 century. Its generationand fabrication gains much interest for the superior property. And in the nanomachining field, femtosecond laser has advantages that can't be replaced on thenanomaterial's fabrication and nanostructure's production for the perfect materialremoval, submicron precision and so on. In this dissertation, theoretical andexperimental studies on nanostructure's micromachining and generation with 775nm,150fs, 1kHz femtosecond pulse laser are present. And the technology and theparameters are explored. It's proved by the research that femtosecond laser is perfectfor the nano micromachining.Key points are classified as following.1. Femtosecond pulse laser machining mechanisms and its characteristics andadvantages are analyzed. Based on the inner and inter national nanoparticles'generation, we work on the mechanism of oxide nanoparticles'production inatmosphere via femtosecond laser using the plasma ejection and redepositiontheory. A series of ablation experiments on oxide nanoparticles'production byfemtosecond laser are carried out based on the theory mentioned. The diametresdistributions are gained by sampling areas that same distance from the ablationcentre. By analyzing experimental data, the relation curve between the particlesize and the laser pulse fluence, pulse numbers is got, while the process ofoxidation are deduced by listing the oxide percentage. All the experimental resultsagree with the theory mentioned.2. We use the surface plasma mode to explain periodical ripples on metals.Experimental data shows that the libration of surface plasma is determined bylaser fluence, and the period of ripples will go up if fluence increases. The surfaceplasma theory is also proved by following growing processes of ripples. Byoptimizing these parameters, period ripples are applied on the micro groovestructures'generation. Through the compare with characteristics of ripples on Si,which obviousely induced by the interferece between the scattering and incidence laser, the metal surface plasma mode are enhanced.3. Combine the characteristics of micromachining of femtosecond laser, carbonnanotubes are fabricated, and some regular appearance are gained. Basic on which,a simple nano electronic device is designed. The advantages are showed duringthe fabrication of nano material.