Three Dimensional Photonics Structures: Design and Applications

Photonics is an emerging technology for light control, emission, and detection. Photonic devices control photons the same way electronic circuits control electrons in active or passive mode depending on the energy requirement of the device. This dissertation will discuss the design, fabrication, testing of photonic structures with applications including imaging and renewable energy. First, we developed a novel lithography method for fluoropolymer resist based on variable pressure electron beam lithography (VP-EBL). VP-EBL proves to be an efficient method for patterning a widely used, but challenging to process, fluoropolymer, Teflon AF. However, rather than solely mitigating charging, the ambient gas is found to alter the radiation chemistry of the exposure process. Specifically, irradiating Teflon AF under water vapor increases the dissolution rate of the exposed regions in non-fluorinated solvents and enables complete patterning in a positive tone process. Second, we designed and fabricated polymeric, structural-based hybrid metasurfaces optical filters that simultaneously focus and filter the light. These filters represent a novel design at the boundary between diffractive optics and metasurfaces that may provide significant advantages for both digital and hyperspectral imaging. The hybrid metasurface filters have a size of 18.5 µm × 18.5 µm and demonstrated focusing efficiency more than 50%. Third, we built a camera based on hybrid metasurfaces color filters with smaller filter size (13.2µm × 13.2µm). The camera relied on the filters’ focused spots for red, green, and blue detection while the higher diffracted orders were used to illuminate ”white” pixels. The smaller filter size reduced the light in the focused spots compared to larger pixel size hybrid filters. However, the new filters enabled an overall quantum efficiency approaching unity. Color error and color conversion matrix were calculated for the proposed model as well. Objects were imaged using the developed camera setup. Last, plasmonic enhancement of bio-hydrogen production from chemical waste was investigated by utilizing plasmonic nanoparticles with near-IR illumination. The nanoparticles have a resonance wavelength matched to the absorbance peak of the bacteria associated with hydrogen production. Illumination with near-IR light emitting diodes demonstrated a more than 2.5-fold increase in hydrogen production compare to illumination with a broadband light source. The presence of the gold– silica core-shell nanoparticles in the media boosted the hydrogen production by an additional factor of 2.5