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 20 of 21 for “"deformable mirror"”.
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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
The Deformable Mirror Demonstration Mission (DeMi) CubeSat operated from July 2020 to March 2022 and demonstrated the successful operation of a Microelectromechanical Systems (MEMS) Deformable Mirror (DM) on orbit for the first time. As part of space-borne adaptive optics systems, DMs correct …
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Electronics development for the Deformable Mirror Demonstration Mission (DeMi)
… microelectromechanical systems (MEMS) based deformable mirror (DM) for the 6U CubeSat Deformable Mirror Demonstration Mission (DeMi) with the objective of increasing the NASA Technology Readiness Level (TRL) of the MEMS DM toward its use for direct exoplanet imaging on a future large aperture …
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The Deformable Mirror Demonstration Mission (DeMi) On-Orbit Analysis
The Deformable Mirror Demonstration Mission (DeMi) is a 6U CubeSat mission to demonstrate the use of a 140 actuator microelectromechanical system (MEMS) deformable mirror (DM) and a closed-loop adaptive optics (AO) system in space. DeMi launched to the International Space Station (ISS) on the NG-13 …
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Simulation and testing of wavefront reconstruction algorithms for the deformable mirror (DeMi) cubesat
… in space are needed. High actuator count deformable mirrors (DMs) used in an AO system enable the required contrasts across sufficient fields of view, but typically have high size, weight, and power requirements, and can be complex to implement. New technologies such as …
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Novel Segment Deformable Mirror Based Adaptive Attenuator Used In Wavelength Division Multiplexed Optical Communications Network
… based on various technologies such as segment deformable mirror, liquid crystal, phase modulation array are given. Simulation results for segment deformable mirror based adaptive attenuator are presented.
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Impact of the boundary layer on pointing and tracking in airborne free-space laser communication links
… algorithms. Also investigated was the use of a deformable mirror to recreate optical phase distortions from boundary layer turbulence. Experiments were conducted with realistic channel effects for multiple look angles between a subsonic aircraft at 29 kft and geosynchronous satellite. …
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Extending imaging depth of multiphoton microscopy
… system, which consists of a wavefront camera and deformable mirror, the wavefront distortion can be measured and corrected. By correcting the distorted wavefront with adaptive optics, resolution and signal level can be preserved at greater imaging depth.
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Segmented Mirror Telescope model and simulation
The Segmented Mirror Telescope (SMT) housed at the Naval Postgraduate School is a unique, state-of-the-art optical instrument built to explore new technologies needed for future spacebased telescopes. A discrete Fourier transform wavefront reconstruction technique developed at Lawrence Livermore …
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Tomographic Reconstruction of Wavefront Aberrations using Multiple Laser Guide Stars
… approach to using real-time wavefront sensor and deformable mirror telemetry from the MLGS system to estimate the vertical distribution of turbulence in the atmosphere is also presented.
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Design and optimization of lightweight space telescope structures
… first topic deals with the design of a secondary mirror support structure. A simple tripod design is studied and optimized in detail. Several baffle--type designs are also studied and compared to the tripod. Finally, the buckling behavior of the bars in the structures is considered. The second …
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Freeform Optical Design Methodologies and Surface Metrology Using Deflectometry
… is applied to the dynamic calibration of a deformable mirror surface, summarized in Chapter 6 and in detail in Appendix D. The key results from each of the contributions to the two fields metrology and design of freeform optics are presented in the summary chapters, with further connections …
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A 3-sided Pyramid Wavefront Sensor Controlled by a Neural Network for Adaptive Optics to reach diffraction-limited Imaging of the Retina
… to be an equivalent sensor. The control of the deformable mirror which can compensate the aberrations is implemented by an artificial neural network based on the acquired sensor data. With the trained neural network, aberrations of 150nm RMS could already be reduced to half the error. The neural …
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Adaptive Mode Control in Few-Mode and Highly Multimode Fibers
… MMF with a uniform Bragg grating, we use a deformable mirror (DM) to perform the wavefront modulation at the fiber input end, where the feedback is based on the ratio of the grating-reflected signal power to the transmitted signal power. At the Bragg grating position of this highly multimode …
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Adaptive optics, aberration dynamics and accomodation control. An investigation of the properties of ocular aberrations, and their role in accomodation control.
… of the eye¿s aberrations independent of the deformable mirror. Dynamic correction of aberrations during steady-state fixation did not affect the accommodation microfluctuations, possibly due to the prior correction of the static aberration level and/or the limited correction bandwidth. The …
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Long exposure point spread function estimation from solar adaptive optics loop data
… control loop data. The wavefront sensor and the deformable mirror data produced by the AG system during normal operation provide enough information to estimate the long-exposure PSE. Using this method, each individual AG-corrected image can be deconvolved with its own estimated PSF. An attempt …
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Multi-Conjugate Adaptive Optics for LINC-NIRVANA : Laboratory Tests of a Ground-Layer Adaptive Optics System and Virtical Turbulence Measurements at Mt. Graham
… the turbulence-induced distortions and one deformable mirror to correct the most turbulent layer. With such a Layer-Oriented Ground-Layer Adaptive Optics (GLAO) system, the area of useful correction is significantly increased. The system is characterized in static and dynamic operation, and …
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Gradient Methods for Large-Scale and Distributed Linear Quadratic Control
… are used to compute controllers for a large deformable mirror, found in a telescope to compensate for atmospheric disturbances. The model of the mirror is obtained by discretizing a partial differential equation. This gives a linear, sparse representation of the mirror with a very large state …
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Characterization, Modeling, and Control of the Nonlinear Actuation Response of Ionic Polymer Transducers
… extended here to the potential application in deformable mirror systems.
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Detector Improvements and Optimization to Advance Gravitational-wave Astronomy
… a high-bandwidth, low-noise, flexure-based piezo-deformable mirror for active mode-matching. Mode-matching losses limit improvements from squeezing as they distort the ground state of the squeezed beam. For broadband sensitivity improvements from frequency-dependent squeezing, it is critical to …
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Studying Ultrafast Vibrational dynamics of Intramolecular Hydrogen Bonds using Broadband Infrared Pump-Probe Spectroscopy.
… necessary. Hence a compressor was built with a deformable mirror for the manipulation of spectral phase to make transform limited pulse. An iterative genetic algorithm was written with a simple single valued feedback for the optimal mirror compression. Nearly transform limited pulses were …
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