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Augmented Reality (AR) devices optically superimpose information over the real world through an optical channel, which often involves an angular bandwidth limited image guide employing Total Internal Reflection (TIR) due to material refractive index constraints. This bottlenecks to packaging size and couples it to the Field of View (FOV) and resolution. Previous architectures have focused on physically increasing the pixel count while reducing pixel size to combat this trade off, while still obeying the inverse relationship between the two. This dissertation discusses and demonstrates two multiplexing methods to address the challenge. By applying wavelength and time multiplexing similar to what is used in optical communication along with newly developed diffraction multiplexing increases the effective optical bandwidth for the AR display. Wavelength multiplexing with two wavelength sources are alternatively used in time sequential manner to in-couple the optical information through the bandwidth limited image guide, to effectively double the physically limited FOV of the image guide. At the output coupler of the image guide, a wavelength sensitive Volume Holographic Grating (VHG) angularly reflects and redistributes each part of the FOV to present a seamless full FOV image. Diffraction multiplexing in time is done by using the Digital Micromirror Device (DMD) in a diffractive manner that produces spatial modulated images at discrete angles, where each FOV per wavelength is further divided into sub-FOVs per each diffraction order. In the projection system, there is a FOV shifter then shifts the sub-FOVs side-by-side and creates a full FOV image. This multiplexing method reduces the display size while maintaining the image resolution, breaking the trade-off between package size and FOV/resolution. The added benefit of this method is that the bulky optics required for the FOV shifter can be placed closer to the image guide, reducing the overall display package size nea

The incidence of anal cancer has been increasing, with an average annual increase of2.2% over 2010–2019. Anal cancer is predominantly related to Human Papillomavirus (HPV) infections. Recent studies have demonstrated the effectiveness of treating precancer in reducing the risk of anal cancer, highlighting the importance of early detection. However, high-resolution anoscopy (HRA), the current standard for anal cancer screening, has a steep learning curve and lacks widespread availability of skilled practitioners. Additionally, HRA-guided anal biopsies are associated with discomfort and potential complications for patients. Scattering-based light sheet microscopy (sLSM) is an imaging technology capable ofimaging unstained tissues with high resolution and a large field of view (FOV). This dissertation explores the potential of sLSM as an in vivo microscopy modality for enhancing anal cancer screening protocols. Through preliminary studies, we have laid the foundational research necessary for the development of sLSM in clinical settings. These investigations have focused on four topics: 1) optimizing the wavelength for sLSM imaging, 2) developing methods to reduce speckle and shadow artifacts, 3) conducting ex vivo imaging studies on fresh anal tissues with a bench sLSM setup to evaluate the feasibility of diagnosing anal precancer, and 4) developing a compact, handheld sLSM probe.

The marine atmospheric boundary layer (MABL), the layer between the ocean and free troposphere, hosts a suite of important atmospheric processes such as heat and temperature flux, gas exchange of carbon dioxide and water vapor, cloud evolution, and aerosol particle transport. To measure these complex processes and provide a complete picture of the MABL, organizations such as the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the Office of Naval Research (ONR) conduct airborne field campaigns that use a multitude of in-situ and remote sensing platforms. This dissertation introduces two studies that aim to improve airborne measurements of 1) ocean surface wind speeds and 2) atmospheric aerosol particles. Both of these studies focus on the in-situ and remote sensing instruments used in NASA’s Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) field campaign that took place from 2020 – 2022. The first study of this dissertation introduces a new 10 m ocean surface wind speed product from the High Spectral Resolution Lidar – generation 2 (HSRL-2) developed at the NASA Langley Research Center (LaRC) and evaluates it using coincident dropsonde surface wind speed data collected during the NASA ACTIVATE field campaign. The HSRL-2 directly retrieves vertically resolved aerosol backscatter and extinction profiles without relying on an assumed lidar ratio or other external aerosol constraints, enabling accurate estimates of the attenuation of the atmosphere and direct retrieval of surface wind speed through probing the variance of ocean wave slopes (i.e., wave-slope variance). The important findings from this study are 1) HSRL-2 surface wind speed retrieval accuracy is 0.15 m s-1 ± 1.80 m s-1, 2) dropsonde surface wind speed measurements most closely match with the Hu et al. (2008) wind speed-wave-slope variance model for surface wind speeds below 7 m s-1, showing that this

Conventional light microscopes lack the ability to produce high-resolution, large field-of-view images in an inexpensive and timely manner. Although light microscopy is a common method for imaging pathology slides for disease detection and diagnosis, the capital and time constraints limit the ability to distribute these devices in point-of-care or low-resource settings as well as the ability to perform rapid disease diagnosis. Lensfree microscopes have emerged as economical and portable devices capable of producing images with high-resolution over a large field-of-view. Lensfree microscopes utilize few components, needing only a light source, sample to image, a sensor to record the light scattered from the illuminated object and a computer to perform the imaging or the object field reconstruction. Capable of producing amplitude and phase images, 3D volume images, and color images, the resolution of lensfree microscopes can be pushed further to expand the number of applications. In this dissertation I discuss computational and experimental methods for continuing to push the resolution and sensitivity of these systems beyond the micron scale. In the second chapter, I discuss computational methods for improving the speed and accuracy of image reconstructions for lensfree digital holography on the nanoscale by proposing nanoscale scalar scattering models. In the following chapter, I discuss a method for improving the detection of airborne particulate matter pollutants in lensfree digital holographic systems by increasing the scattering cross-section of sub-pixel sized particles using a pre-deposited film. Finally, I discuss the first implementation of time-gated fluorescence lensfree imaging for improving the SNR of lensfree fluorescence imaging, removing the need for spectral filters between the sample and sensor.

Minimally invasive surgery exhibits many advantages compared to open surgery, but it is limited in safety and efficiency by contemporary laparoscopes due to their non-stationary nature and inherently exhibited trade-off between resolution and instantaneous field of view (FOV). These limitations increase the likelihoods of adverse patient outcomes resultant from lacerations or electrical burns outside of the laparoscope FOV. Furthermore, surgical team members may experience fatigue or injury when sacrificing ergonomics to accommodate laparoscope positioning. To address the limitations of contemporary laparoscopes, a multi-resolution foveated laparoscope (MRFL) was proposed and developed. The MRFL features simultaneous optical imaging of a high-resolution narrow FOV (like that of a traditional laparoscope) and a lower resolution wide-angle view. The most recent MRFL design includes electrically tunable lenses (ETLs) and a dual-axis scanning device that respectively facilitate optical zooming and panning of the high-resolution view to any region within the wide-angle view. A functioning MRFL prototype was made from the design as a proof of concept, but its utility is limited by its imaging performance. In this dissertation, the advancement of MRFL imaging performance is discussed at length. Using the same lens design as the system discussed above, an improved prototype with higher image fidelity was developed for use in a porcine surgery study. Further improvements made in support of the study facilitated successful utilization of the prototype during in-vivo testing, but participant feedback confirms that its utility is still predominantly limited by its image quality. Following the study, a high-throughput multi-resolution foveated laparoscope (HT-MRFL) was designed to address the imaging limitations of the MRFL prototype while exhibiting reduced weight and size. An HT-MRFL benchtop prototype has been constructed using 3D printed opto-mechanics and its performance is