This thesis relates a technique for increasing the optical strength of NaCl and KCl single-crystal samples. The 1.06-μm pulsed laser damage thresholds were increased by factors as large as 4.6 for a bulk NaCl single-crystal sample. The bulk laser damage breakdown threshold (LDBT) of the crystal was measured prior to and after heat treatment at 800*C using a Nd:YAG laser operating at 1.06 μm. Bulk and surface LDBTs were also studied on samples annealed at 400° C. These samples showed differences in damage morphology on both cleaved and polished surfaces, and the cleaved surfaces had improved damage thresholds. However, neither the polished surfaces nor the bulk showed improved threshold at the lower annealing temperature.

The Complementary Metal-Oxide-Semiconductor (CMOS) industry has seen tremendous developments over the past several decades and state-of-the-art fabrication technology has likewise been developed. This fabrication technology develops Photonic Integrate Circuits (PIC) which can guide, split, and modulate photonic waves within a small chip scale. On-chip optical phased arrayed waveguides that operate at high power overcome the current limitations of some conventional applications. This paper discusses two applications of on-chip optical waveguide systems: optical phased array (OPA)-based Light Detection and Range (LiDAR) and waveguide array Dielectric Laser Accelerator (DLA). Both the LiDAR and DLA structures require similar properties to achieve optimized performance. These properties are as follows: capability to handle high power, the ability to split the high power evenly through several waveguide branches and distribute the same degree of optical phase on each branch at specific spatial locations, efficient designs of active phase-tuning structures, and the ability to re-combine several waveguide branches into the sub-wavelength pitch spacing array without crosstalk. Additionally, both structures must resolve specific fabrication challenges on each waveguide component. To address these issues, this paper discusses the theoretical reviews of OPA, the Laser-Induced Damage Threshold (LIDT) of optical waveguide materials, and techniques to reduce crosstalk in sub-wavelength pitch size arrays, such as extreme skin-depth (e-skid) waveguides and propagation constant mismatched waveguides. We propose optimized designs for both OPA-based LiDAR and waveguide array DLA with passive and active devices, respectively, and explain the optimized parameters and its simulation results for each component from the full layout of devices. Furthermore, we discuss the fabrication process of the devices and show the resolutions of fabrication challenges, such as trapping void gaps in an e-skid array structure, writing errors of electron beam lithography of large dense patterns, and silicon nitride to silicon hybrid waveguide pattern alignments. Next, we show the experimental setups and the measurement results from the fabricated OPA devices and analyze the results. Finally, this paper concludes the research of the proposed devices and proposes more designs for both OPA-based LiDAR and waveguide arrayed DLA structures that can further increase increase its performance.<br>