| In 1958 the first integrated circuit was demonstrated to combine transistors, resistors, and capacitors [36]. To this date fabrication technology has been driven by the growing demand for monolithically constructed, densely packed electronic components. The exponentially shrinking device size decreased the feature dimensions from 10 microns to 32 nm and grew transistor count from 2,300 to over 2,000,000,000 in Intel's 4004 and Intel Kentsfield XE microprocessors. The benefits of micro- and nano-fabrication was not limited to just computer chips. MEMs, spintronic, microfluidics, and integrated photonics were all made possible by the ever expanding ability to form complex geometries, on a wide variety of materials, on a micron and submicron scale.;This dissertation is part of an effort to design and fabricate novel integrated photonic devices compatible with standard electron beam and photo lithography and utilize a readily available material base. We aim to create devices with a decreased footprint on a chip and operate in the infrared, visible, and UV spectra. We present two general sections, the first is a theoretical effort to find the fundamental design geometries for a variety of optical problems. The second section is an experimental demonstration of techniques and devices for novel optical phenomena in an integrated package.;In the theoretical section we develop and apply computational evolutionary algorithms to explore problems of light confinement, coupling, and guiding in two and three dimensional device geometries. Our general aim is to find a global limit to optimal device geometry and performance given a set of constrains. Experimentally, we demonstrate an efficient design and a fabrication process for a short development cycle of photonic devices. For the design part of the workflow, we develop a computational approach to explore device geometries with minimum initial assumptions for a variety of photonic problems. For the fabrication part of the workflow, we optimize dielectric deposition, electron beam lithography, resist post processing, etching, and cladding to yield low loss photonic devices in silicon nitride. We measure the propagation losses in our devices and demonstrate their origin. We also design and test cavities to demonstrate novel nonlinear optical phenomena. |
