A new system for multi-photon lithography (MPL) was developed and used to fabricate three-dimensional (3D) structures with higher aspect ratio, better resolution, improved fidelity, and reduced structural distortion relative to a conventional implementation of MPL. A set of curved waveguides (Rbend = 19 μm, and 38 μm) and straight waveguides (length = 50 μm, Rbend = ∞) were fabricated in an epoxide photopolymer and optically characterized using light having a wavelength in vacuum of λ0 = 2.94 μm. The optical performance of the waveguides was compared to novel spatially-variant photonic crystals (SVPCs) previously studied in the group. The waveguides were found to guide light with 90% lower efficiency, due to mode leakage. The study provides further evidence that SVPCs operate not through total internal reflection, but rather through self-collimation, as designed. 3D uniform-lattice photonic crystals (ULPCs) were fabricated by MPL using a commercial acrylate photopolymer. The ULPCs were optically characterized at λ0 = 1.55 μm. A laser beam with adjustable bandwidth was used to measure the self-collimation in the ULPCs. For the low bandwidth beam, vertically polarized light was self-collimated, whereas horizontally polarized light diverged. The transmission efficiency of the ULPCs was also measured as a function of fill factor. The ULPC having a fill factor of 48% exhibited 80% transmission. An etching process was also developed for non-destructively removing Au/Pd coatings that must be deposited onto structures to image them by scanning electron microscopy. The structural and optical integrity of the samples was found to be maintained despite etching. The sputter-coated sample sustained no structural damage when exposed to the λ0 = 1.55 μm. However, the metal coating resulted in diminished transmission efficiency due to the high reflection of the 1.55 μm beam by the metal coating.
If this is your thesis or dissertation, and want to learn how to access it or for more information about readership statistics, contact us at STARS@ucf.edu.
Doctor of Philosophy (Ph.D.)
College of Sciences
Length of Campus-only Access
Doctoral Dissertation (Open Access)
Sharma, Rashi, "Improved System for Fabrication and Characterization of Nanophotonic Devices by Multi-photon Lithography" (2019). Electronic Theses and Dissertations, 2004-2019. 6619.