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Full-Text Articles in Engineering
Computational Optical Imaging: Applications In Synthetic Aperture Imaging, Phase Retrieval, And Digital Holography, Dennis Joseph Lee
Computational Optical Imaging: Applications In Synthetic Aperture Imaging, Phase Retrieval, And Digital Holography, Dennis Joseph Lee
Open Access Dissertations
Computational imaging has become an important field, as a merger of both algorithms and physical experiments. In the realm of microscopy and optical imaging, an important application is the problem of improving resolution, which is bounded by wavelength and numerical aperture according to the classic diffraction limit. We will investigate the resolution enhancement of phase objects such as transparent biological cells. One key challenge is how to measure phase experimentally. Standard interferometric techniques have the drawback of being sensitive to environmental vibrations and temperature fluctuations, and they use a reference arm which requires more space and cost. Non-holographic methods provide …
Circular Bessel Field Statistics And The Pursuit Of Far-Subwavelength Resolution, Yulu Chen
Circular Bessel Field Statistics And The Pursuit Of Far-Subwavelength Resolution, Yulu Chen
Open Access Dissertations
The statistical description of wave propagation in random media is important for many applications. While polarized light in systems with weakly interacting scatterers and sufficient overall scatter has zero-mean circular Gaussian statistics, the underlying assumptions break down in the Anderson localization and weakly scattering regimes. Although probability density functions for wave intensity and amplitude exist beyond Gaussian statistics, suitable statistical descriptions for the field with strong and weak random scatter were unknown. The first analytical probability density function for the field that is effective in both the Anderson localization regime and the weakly scattering regime is derived by modeling the …
Novel Techniques For Quasi Three-Dimensional Nanofabrication Of Transformation Optics Devices, Paul R. West
Novel Techniques For Quasi Three-Dimensional Nanofabrication Of Transformation Optics Devices, Paul R. West
Open Access Dissertations
Current nanofabrication is almost exclusively limited to top-down, two-dimensional techniques. As technology moves more deeply into the nano-scale regime, fabrication of new devices with quasi three-dimensional geometries shows great potential. One excellent example of an emerging field that requires this type of non-conformal 3D fabrication technique is the field of Transformation Optics. This field involves transforming and manipulating the optical space through which light propagates. Arbitrarily manipulating the optical space requires advanced fabrication techniques, which are not possible with current two-dimensional fabrication technologies. One step toward quasi three-dimensional nanofabrication involves employing angled deposition allowing new growth mechanisms, and enabling a …