Additive Manufacturing and Applications of Silica Glass Materials

The difficulty in shaping and fabrication of miniaturized features on glass structures using conventional fabrication techniques makes the recent advancements in glass manufacturing necessary. Pioneer efforts towards glass additive manufacturing have proven to be the nexus between the past and the future of glass fabrication. Additive manufacturing potentially allows for speed, scalability, environmental and cost friendliness, high resolution as well as flexibility for functional glass materials. Adapting additive manufacturing methods toward glass fabrication is thus of great importance. We first fabricated three dimensional doped and undoped Borosilicate glasses via stereolithography which exhibited comparable optical properties to commercial glasses, irrespective of their low softening temperatures. Processing parameters of densification and calcination were optimized to achieve structural and optical stability of the resulting undoped and Cerium-doped borosilicate glass. Optical parameters including the optical band gap, Urbach energy and refractive index were deduced from the optical absorption spectra with comparable quality to doped glasses fabricated by other methods. vii The glasses exhibited a band gap of 3 eV, Urbach energy of 0.75 eV and refractive index of 2.14 for 8% Ce-doped glass, respectively. The results indicate the suitability of Ceriumdoped glass fabricated by stereolithography for luminescence applications and that additive manufacturing could be promising for borosilicate glass fabrication. We also investigated the use of the stereolithography technique for fabrication of functionally graded materials with emphasis on gradient refractive index optics. These class of materials allow for planar surfaces which make mounting in complex optical systems much easier in addition to providing enhanced optical properties. They find applications in facets such as micro-optical telescopes, solid state lasers, fiber collimators, optical data storage etc. Stereolithography is a good technique for gradient refractive index optics because it allows for a flexibility of dopant inculcation so that there is a variation in the refractive within the glass structure. Our simulation results for the gradient optical lens designs based on the adoption of the precursor cum resin sludge properties showed measurable and tunable optical properties such as spherical aberrations. Experimental results establish stereolithography as a veritable technique and show the propensity for the adaptation of this technique for the fabrication process