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In this work, the possibility of fabricating true 3D glass-ceramic microstructures from a variety of hybrid organic-inorganic silicon-zirconium-based photoresists SZXY is investigated. To this extent, FTIR-ATR analysis of the sols, gels and polymers was carried out. Thermogravimetric analysis was performed to learn how the polymer changes as it is heated. Also, X-ray diffraction experiments of the calcinated polymer powders and structures were performed. Using direct laser writing and SEM imaging the resolution and post-annealing shrinkage of fabricated microstructures were evaluated. Using the sol-gel method the silicon-zirconium based-prepolymer SZXY was prepared with a variety of silicon and zirconium molar ratios respectively X:Y. To examine the effect that a varying zirconium ratio has on the condensation process FTIR-ATR spectra were collected. It is shown that an increase of the molar ratio of zirconium in the initial prepolymer resulted in an increase in the number of Zr-O-Zr condensation bonds and a consequent decrease of Si-O-Si bonds. Using thermogravimetric analysis, it is shown that annealing results in a weight loss between 51 and 62 % due to the decomposition of the organic part of the polymer. To build on these results and give insight into the specific crystal phases present, X-ray diffraction spectra of the polymer powder and hexagonal scaffoldings calcinated at various temperatures were registered. Analysis of these spectra and comparison to theoretical data shows that an additional two crystal phases are obtained: monoclinic zirconia and zirconium orthosilicate. This means that by varying the initial molar ratio of silicon and zirconium it is possible to obtain four different crystal phases. Woodpile structures and solid cubes were fabricated by way of direct laser writing. Analysis of these structures was then performed using scanning electron microscopy imaging. Measurement of the woodpile line width has shown that increasing the ratio of zirconium leads to thicker lines, meaning that in order to obtain the highest resolution the prepolymer with the least amount of zirconium should be used. Furthermore, to evaluate the effect that calcination has on the fabricated structures the diagonals of the fabricated cubes were measured before and after calcination. It was found that volume shrinkage was between 64 and 80 %, with structures fabricated using a prepolymer with more zirconium shrinking. In addition, no significant deformation of structures was observed after calcination at 1000 °C. In conclusion, varying the molar ratio of silicon and zirconia in the prepolymer gives rise to a variety of crystal phases after calcination. The highest resolution is obtained by using a prepolymer with the lowest ratio of zirconia with linewidth as small as 60 nm. Post-fabrication calcination results in a shrinkage of the fabricated structures between 64 and 80 % and a weight loss between 51 and 62 %, with structures fabricated using a prepolymer with more zirconium shrinking less.

Recently, it has been observed that a correct choice of the geometry of three-dimensional axisymmetric photonic crystals allows not only the removal of some angular components but also a strong enhancement of the on- and near axis components of a beam – a result previously unfamiliar in spatial filtering. This unexpected phenomenon, leading to a formation of a narrow bright peak in the far field of the transmitted radiation, was termed the super-collimation. Unfortunately, the fabrication of such three-dimensional structures technologically is a very challenging task. Therefore, the idea to combine the manufacturing advantages of flat optics and the functionalities of three-dimensional photonic crystals by the use of a concentric symmetry meta-mirror was suggested. A concentric symmetry meta-mirror is a device consisting of a thin transmissive concentric diffraction grating positioned close and parallel to the surface of a flat mirror. The purpose of this work is to investigate the prospects of the effect of super-collimation in such a configuration. In the thesis, a concentric symmetry meta-mirror is fabricated and the propagation of a diverging Gaussian beam in such a double-pass system is studied both numerically and experimentally. The focus is given to two main dependencies: the dependence of enhancement of the on-axis intensity of the reflected beam on the distance between the diffraction grating and the mirror and the dependence of the super-collimation peak angular width on the same distance. The study shows that the former dependence is periodic and increasing with a period approximately equal to half a Talbot length, whereas the latter dependence follows a hyperbolic law. Moreover, it proves that the effect of super-collimation observed in three-dimensional axisymmetric photonic crystals can be achieved by a concentric symmetry meta-mirror. Experimental results are in good accordance with the ones obtained numerically. The maximum enhancement of the axial intensity of a beam observed experimentally was approximately seven-fold.