Optimization of selective laser etching for assembly-free 3D micro-mechanic fabrication

The glass was proven to be a material of choice in many science and engineering fields. While various glass processing techniques exist, most of them are very complicated or completely unable to produce 3D high-fidelity (~μm) structures out of glass. It limits the adoption of 3D glass structures in many areas. One of the most promising technology to produce 3D glass structures is selective laser etching (SLE). Potentially, many types of glasses and crystals can be processed in this way. Nevertheless, this process is not exploited widely. The problems lie in the complex nature of light-matter interactions needed to induce modifications and challenges in optimizing the technique for true 3D fabrication. Laser parameters, translation velocity, etching properties are all important factors that cannot be disregarded. Overall, while the premise of SLE is simple, so far realization was proven to be rather complicated. Thus, this work aims to discover ways to simplify the production methodology of SLE while still maintaining sufficiently low surface roughness of a few hundred of nanometers and the possibility to acquire true 3D structures. A compromise between various fabrication parameters is found which allows meeting these criteria. Non-intuitive dependencies on scanning parameters are obtained which shows that not only radiation and material interaction are important, but also scanning techniques themselves change inscribed modifications. Optimized techniques are then used to manufacture complex high surface quality structures such as microfluidic systems and assembly-free movable micromechanical structures proving that this optimization can be used for functional device fabrication.