The underlying drivers of refractive error development in the human eye remain open areas of research. Axial elongation, peripheral ametropia, neurotransmitters at the retinal surface and environmental stimuli are a few factors that have been studied to describe the onset and progression of refractive error development. However, the ametropia puzzle remains unsolved and the number of people afflicted by ametropia is growing. One possible driver for refractive error development is distortion in the retinal image. However, no systems are available to objectively measure ocular distortion. To enable the measurement of ocular distortion, a novel imaging system is created and tested in a sample population. Using a modified fundus camera, a target is projected onto the retinal surface and imaged to a detector. A distortion criterion for a rotationally non-symmetric optical system is used to analyze the resulting distortion pattern. A simulated population of one thousand different configurations, for a model eye spanning -20 to +9 D, is used to investigate ocular distortion prior to human trials. A small human trial cohort was imaged using the modified fundus camera and compared to the simulated data set. The repeatability of the distortion measurements and its relationship to refractive error is investigated.

In this thesis, several aspects of GaAsSb/AlSb multiple quantum well (MQW) heterostructures have been studied. First, it was shown that the GaAsSb MQWs with a direct band gap near 1.5 μm at room temperature could be monolithically integrated with AlGaSb/AlSb or AlGaAsSb/AlAsSb Bragg mirrors, which can be applied to Vertical Cavity Surface Emitting Lasers (VCSELs). Secondly, an enhanced photoluminescence from GaAsSb MQWs was reported. The photoluminescence strength increased dramatically with arsenic fraction as conjectured. The peak photoluminescence from GaAs(0.31)Sb(0.69) was 208 times larger than that from GaSb. Thirdly, the strong photoluminescence from GaAsSb MQWs and the direct nature of the band gap near 1.5 μm at room temperature make the material favorable for intermixing studies. The samples were treated with ion implantation followed by rapid thermal annealing (RTA). A band gap blueshift as large as 198 nm was achieved with a modest ion dose and moderate annealing temperature. Photoluminescence strength for implanted samples generally increased with the annealing temperature. The energy blueshift was attributed to the interdiffusion of both the group III and group V sublattices. Finally, based on the interesting properties of GaAsSb MQWs, including the direct band gap near 1.5 μm, strong photoluminescence, a wide range of wavelength (1300 – 1500 nm) due to ion implantation-induced quantum well intermixing (QWI), and subpicosecond spin relaxation reported by Hall et al, we proposed to explore the possibilities for ultra-fast optical switching by investigating spin dynamics in semiconductor optical amplifiers (SOAs) containing InGaAs and GaSb MQWs. For circularly polarized pump and probe waves, the numerical simulation on the modal indices showed that the difference between the effective refractive index of the TE and TM modes was quite large, on the order of 0.03, resulting in a significant phase mismatch in a traveling length larger than 28 μm. Thus the FWM conversion efficiency was exceedingly small and the FWM mechanism in SOAs used for investigation of all-optical polarization switching was strongly limited.

Sol-gel materials are an important material class, as they provide for easy modification of material properties, good processability and routine synthesis. This allows for the tailoring of the material properties to the needs of specific device designs. In the case of electro-optic modulators with a coplanar or coplanar strip (CPS) electrode design, sol-gel cladding materials can be used to confine the light to the electro-optic material as well as to concentrate the electrical field used for poling and driving the modulator. Another important material property that can influence the poling efficiency is the conductivity of the material surrounding the electro-optic material, and this property can also be controlled. In this dissertation I discuss several approaches to altering the material properties of sol-gel materials in order to achieve a specific performance objective. The optical loss in the telecom regime as well the refractive index will be discussed. I will introduce a novel titania-based family of sol-gel materials, which exhibit very high refractive indices, tuneability and high dielectric constant (ε). Coplanar electrode design is useful for device platforms that do not allow for a microstrip geometry, such as silicon and Si₃N₄ devices. CPS electrodes however bring new challenges with them, especially optimizing the poling process. I will discuss a method for characterizing coplanar poled polymer films by a modified Teng-Man technique as well as with second harmonic microscope (SHM). SHM allows for an almost real-time mapping of the Pockels coefficient. The described method allows for quantitative measurements of the Pockels coefficient in a poled film with spatial resolution at the micron level. Finally, I will discuss the device design considerations for a silicon-EO hybrid modulator. Optimal dimensions for the silicon waveguide are shown and the feasibility of the proposed electrode design for high speed operation is theoretically shown. All design parameters, including electrode spacing and height are optimized towards the highest possible figure of merit. The functionality of a simple test device is shown. For Si₃N₄ waveguides optimal dimensions are found as well and the influence of a high ε sol-gel side cladding is examined.

The goal of this dissertation research is to develop and demonstrate a functioning snapshot imaging spectropolarimeter for the long wavelength infrared region of the electromagnetic spectrum (wavelengths from 8-12 microns). Such an optical system will be able to simultaneously measure both the spectral and polarimetric signatures of all the spatial locations/targets in a scene with just a single integration period of a camera. This will be accomplished by combining the use of computed tomographic imaging spectrometry (CTIS) and channeled spectropolarimetry. The proposed system will be the first instrument of this type specifically designed to operate in the long wavelength infrared region, as well as being the first demonstration of such a system using an uncooled infrared focal plane array. In addition to the design and construction of the proof-of-concept snapshot imaging spectropolarimeter LWIR system, the dissertation research will also focus on a variety of methods on improving CTIS system performance. These enhancements will include some newly proposed methods of system design, calibration, and reconstruction aimed at improving the speed of reconstructions allowing for the first demonstration of a CTIS system capable of computing reconstructions in 'real time.'

This dissertation reports on the development of the quantum-theory-based Metastable Electronic State Approach (MESA) for modeling light-matter interactions in the near- IR to long-IR wavelength regions. MESA is a first-principle description for the non- linear optical response of the medium, making use of the metastable solutions of the stationary Schro ̈dinger equation including the quasi-static homogeneous electric field. Its primary purpose is to function as a computationally efficient model of the medium with minimal parameters. The theoretical underpinnings and preliminary numerical tests of MESA have been demonstrated in recent publications. This dissertation develops upon previous work by finding numerical solutions for metastable resonances to bring to fruition the single-state Metastable Electronic State Approach (ssMESA). To create the numerical toolkit to practically implement ssMESA, we utilize the Single-Active-Electron (SAE) approximation, design a parameter-free model, and present a quantitative assessment of the theory, initially for noble-gas atoms. Additionally, with the use of data from the multi-electron hybrid-antisymmetrized Coupled Channel Approach, the ssMESA has been extended to molecular Nitrogen. The extension to Nitrogen demonstrates the utility of the ssMESA beyond the SAE description and noble gases, moving towards a full model of the atmosphere. The core of this dissertation deals with the extension beyond ssMESA, first realized in the form of “Post-Adiabatic” corrections. The post-adiabatic (paMESA) model is used to demonstrate the wavelength-dependent enhancement of strong-field ionization. We further show that the paMESA is efficient in computationally capturing the light-matter dynamics in two-color optical pulses. An important outcome of this dissertation is a first of its kind experiment-theory comparison of the transient nonlinear response for a light-matter interaction model applicable to optical filamentation. The quantitative agreement has been demonstrated for peak intensities with complex dynamics due to competition between self-focusing and plasma-induced defocusing where the optical field acts in the intermediary region between perturbatively and a strong field. The comparison encompasses more than forty experiments on several gas species and highlights the robustness of the MESA. Finally, in looking forward the MESA is developed beyond the paMESA model by explicitly including the first excited state to describe non-adiabatic e↵ects in a two-state system. The inclusion of the excited state eliminates the need for the sole fit parameter in the paMESA model as the initial exploratory step toward building a multi-state MESA. In summary, the work described in this dissertation elevates the MESA from the proof-of-principle stage and transforms this framework into a practical tool with applications throughout Nonlinear Optics.

The optical engineering exploration in making the capable of diffractive multifocal Intraocular lens (MIOL) will be be presented in the dissertation. The Diffractive multifocal IOL is a surgical implanted medical devices that have potential to provide the recovery of full range functional vision for cataract patients. The developed design principle, fabrication technique, and performance verification method associated with the diffractive MIOLs will be reported and discussed in this presentation. Two examples will be provided as a demonstration for the capability in the creation of diffractive MIOLs

An on-axis, vibration insensitive, polarization Fizeau interferometer is realized through the use of a novel pixelated mask spatial carrier phase shifting technique in conjunction with a low coherence source and a polarization path matching mechanism. In this arrangement, coherence is used to effectively separate out the orthogonally polarized test and reference beam components for interference. With both the test and the reference beams on-axis, the common path cancellation advantages of the Fizeau interferometer are maintained. Microwave modulation of a high powered red laser diode is used to create a 15 mW laser source having a coherence length of 250 um with minimal sidelobe ringing. With a 15 mW source, the maximum camera shutter speed, used when measuring a 4% reflector, was 150 usec, resulting in very robust vibration insensitivity. Additionally, stray light interference is substantially reduced due to the source's short coherence, allowing the measurement of thin transparent optics. Experimental results show the performance of this new interferometer to be within the specifications of commercial phase shifting interferometers.This work starts with a basic review of interferometry, phase shifting, and polarization as a lead in to a description of the theory and operation of the pixelated mask spatial carrier phase shifting technique. An analysis of the standard Fizeau Interferometer is then given. This is followed by detailed theoretical discussion of the path matched vibration insensitive (PMVI) Fizeau, which includes a theoretical model of the effects of multiple beam return from the test surface when measuring high value reflectors. The coherence properties of laser diodes are then discussed, a theoretical model for the effects of high frequency drive current is derived, and experimental results are given. Finally, the performance of the PMVI Fizeau is experimentally analyzed, potential error sources discussed, and suggestions for improvements provided.

An induced evanescent polarization imaging system and associated topics using a solid immersion lens (SIL) are demonstrated in this dissertation. The physics and properties of induced polarization signal of the SIL are studied by both simulations and experiments. In the SIL optical system, with a linearly-polarized incident illumination light at the entrance pupil, an orthogonal component of polarization is induced upon reflection from the SIL. This orthogonal polarization signal contains information of both air gap height h between the bottom of the SIL and the top surface of the sample. It is used as the air gap control signal in the SIL system. An experimental SIL near-field microscope setup is developed and demonstrated. A compact mechanical package is developed for a standard microscope that implements a SIL on a retractable bimorph swing arm. With the compact package mounted on an inverted microscope, far-field and near-field images are obtained at the same location by moving the SIL with the swing arm. A 25 μm diameter and 0.8 μm high circular pedestal in the center of the flat portion of the SIL is fabricated, along with a conically shaped surrounding region. The image contrast enhancement, high lateral resolution and height information are obtained with induced polarization evanescent imaging using SIL. Experiments are conducted by imaging features on a patterned Si substrate. Imaging theory is used to predict optimum orientation of high-spatial-frequency samples, and a topographical image is derived from the induced polarization image through a calibration procedure. A numerical aperture of NA=1.5 is used in the experiment. Height accuracy of ± 2nm is demonstrated with a known sample. A new lithography system employing a solid immersion lens (SIL) is proposed and primitive experiment results are presented. SIL technology is a direct-writing technique, where high resolution is easily achieved without a mask.

Fluidic lenses have been developed for ophthalmic applications. The lenses use a pressure differential to deform a membrane, which separates two fluids with different indexes of refraction. The change in membrane shape creates changes in the optical wavefront. By utilizing different boundary conditions on the membrane, the progression of the membrane shape can be controlled. Specifically, a circular restraint is used to produce optical power, whereas a rectangular restraint is used to produce a combination of power and astigmatism. These lenses are analyzed for dominant properties and wavefront quality. By combining 2 rectangular restraint lenses at 45° and a circular restraint lens, both orthogonal second order Zernike astigmatisms as well as second order power can be independently controlled. This combination can also be described as independent control of ophthalmic cylinder, cylinder axis, and power, which is required to create a basic phoropter. A fluidic phoropter is demonstrated and analyzed in this manuscript.

Surface textures add another dimension to optical design. They can be used to redirect light, isolate spectral bands, and enhance optical fields. They effectively take up no space, so can be applied to any optical surface–from intermediary elements to substrates. Here I present three applications of textured surfaces for light harvesting. The first project places scattering textures inside a film that can be applied to windows to scatter infrared light towards solar cells at the edges. The collected energy is then used to power tinting films. The second project uses modular diffractive structures to increase the absorption in solar cells. Lastly, structured silver surfaces are used to enhance plasmonics fields and increase two-photon excitation fluorescence.