Thermal aspects of laser-based measurement and ultrafast laser processing of dielectric materials.

摘要

Two extreme regimes for laser applications on dielectric materials are presented in this dissertation. First, two independent novel techniques that use low power laser light to make precision non-contact measurement of liquids are introduced: (1) real-time concentration measurement of NaCl-H₂O and MgCl₂-H₂O aqueous mixtures in a flowing system, and (2) temperature or concentration measurements of liquids, including water, ethanol, methanol, 1-proponal, and their mixtures, at a free surface as well as a solid-liquid interface. These measurement techniques exhibit very high spatial and temporal resolutions, making them good candidates for use in microscale and MEMS-based measurement technologies.; Another extreme of laser applications is materials processing using high power ultrashort laser pulses, which exhibits exciting new opportunities for non-contact materials modification with high precision and high feature quality. The second part of this dissertation focuses on modeling the interactions between ultrashort laser pulses and dielectrics. Present models effectively characterize several dominant parameters during ultrafast laser processing of dielectrics. Good agreement has been found between the model predictions and the experimental results. Future research will be directed towards the utilization of these model predictions to enhance energy deposition and material removal rate during ultrafast laser processing, improve machined features, and optimize technologies that involve laser-microstructures fabrication.