Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"optical aberrations"”.
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Minimizing electron optical aberrations
… in high voltage ("""" 100 k V) electron optical instruments, especially used for lithography (SCALPEL) and high resolution electron microscopy (HREM). Since the invention by Berger and Gibson [1) in 1989, SCALPEL (SCattering with Angular Limitation in Projection Electron-Beam Lithography) …
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Fast Neuronal Imaging using Objective Coupled Planar Illumination Microscopy
… neurotechniques such as electrophysiology and optical imaging are constrained by the number of neurons whose activities can be simultaneously measured or the speed of measuring such activities. We have developed a novel light-sheet based technique called Objective Coupled Planar Illumination: …
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An algorithm for rapid measurement of aberrations in pairs of out-of-focus images
… I present a new technique for measuring the optical aberrations produced by a telescope, with an eye towards future use of these aberration measurements to align wide-field telescopes. This method determines the aberrations by simultaneously fitting a pair of oppositely defocused images to a …
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Three-Dimensional Single Particle Tracking on the Two -Photon Microscope
… technique scans only a single plane but utilizes optical aberrations which have been introduced into the optical system that break the axial symmetry of the point spread function and serves as an indicator of the particle's axial position. We identified several different modes of motion in sucrose …
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Development of a new Infrared Pyramid Wavefront Sensor
… of an adaptive optics system compensating the optical aberrations due to atmospheric turbulence for astronomical observations is sensing the wavefront at near-infrared wavelengths, where many bright stars are found, which can be used as guide stars and have no visible counterparts. A pyramid …
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Sensorless adaptive optics in advanced microscopy techniques
… to restore diffraction limited performance in optical systems that are adversely affected by optical aberrations. In this doctoral thesis adaptive optics technology has been implemented in systems for imaging and micromanipulation whose performance degrade with increasing penetration depth due …
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Commissioning of the Adaptive Optics System NAOS-CONICA for the VLT : the way to First Light
… of a technique for the calibration of static optical aberrations. Since the instrument is designed to achieve absolute Strehl ratios higher than 70%, even the accumulation of residual static wavefront perturbations arising from optical components in the imaging path, critically affect the …
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Modeling and Analysis of Optical Blur for Everyday Photography
Optical blur obscures image detail due to the camera's optics. The blur appearance depends on the scene's depth, wavelength, as well as the camera. The inference of such information --- optical calibration, image deblurring, and depth estimation -- is of great interest to computer vision. Existing …
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Computational imaging in biology
… of multiple scattering and correction of heavy optical aberrations, and label free contrast enhancement. Single pixel imaging allows for imaging at high speeds and extended wavelengths compared to traditional cameras. Pared together with computational and inverse problem techniques super …
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On-Orbit Characterization of a Microelectromechanical Systems (MEMS) Deformable Mirror (DM): Mission Results from the Deformable Mirror Demonstration Mission (DeMi) CubeSat
… space-borne adaptive optics systems, DMs correct optical aberrations and speckles due to mechanical, thermal, and optical effects. MEMS DMs are particularly well suited for space systems because they are compact, low power devices and have a high density of actuators to provide high precision …
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Dynamics and Control of Membrane Mirrors for Adaptive Optic Applications
… that membrane mirror would provide quality optical imaging capabilities. However, membrane mirrors exhibit undesirable vibrations that can be caused by thermal gradients or internally-induced excitations. The undesirable vibration degrades the performance of these mirrors. Hence, it is …
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Path calibration algorithms for many-aperture fiber-linked broadband hypertelescopes
… separately and correlated in software, but optical and infrared interferometry cannot currently use this approach because absolute phase must be captured. Instead, the beams from each sub-telescope must be brought together and interfered pairwise in order to measure relative phases and …
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Path from Photorealism to Perceptual Realism
… limited dynamic range, low spatial resolution, optical aberrations, and vergence-accommodation conflicts. To push the limits of the overall fidelity, we present a High-Dynamic-Range Multi-Focal Stereo display (HDR-MF-S display) with an end-to-end imaging and rendering system. The system can …
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Computational optical coherence tomography for polarization-sensitive imaging, aberration correction, and wavefront measurement
… this thesis, multiple longstanding challenges in optical imaging are solved by the development of new computational imaging methods, where computational imaging does not simply refer to simulation or modeling, but to the entirety of an imaging technology in which significant computation is …