Download or read book Dynamic Characterization Modeling and Control of a Deformable Mirror for Adaptive Optics Ophthalmic Applications written by Erika Odlund and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems written by Zhizheng Wu and published by Springer Science & Business Media. This book was released on 2012-10-21 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems presents a novel design of wavefront correctors based on magnetic fluid deformable mirrors (MFDM) as well as corresponding control algorithms. The presented wavefront correctors are characterized by their linear, dynamic response. Various mirror surface shape control algorithms are presented along with experimental evaluations of the performance of the resulting adaptive optics systems. Adaptive optics (AO) systems are used in various fields of application to enhance the performance of optical systems, such as imaging, laser, free space optical communication systems, etc. This book is intended for undergraduate and graduate students, professors, engineers, scientists and researchers working on the design of adaptive optics systems and their various emerging fields of application. Zhizheng Wu is an associate professor at Shanghai University, China. Azhar Iqbal is a research associate at the University of Toronto, Canada. Foued Ben Amara is an assistant professor at the University of Toronto, Canada.
Download or read book Design Fabrication and Characterization of MEMS Deformable Mirrors for Ocular Adaptive Optics written by Hyunkyu Park and published by . This book was released on 2009 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Control of a Magnetic Fluid Deformable Mirror for Ophthalmic Adaptive Optics Systems written by Azhar Iqbal and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Control of a Magnetic Fluid Deformable Mirror for Ophthalmic Adaptive Optics Systems written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics (AO) systems make use of active optical elements, namely wavefront correctors, to improve the resolution of imaging systems by compensating for complex optical aberrations. Recently, magnetic fluid deformable mirrors (MFDM) were proposed as a novel type of wavefront correctors that offer cost and performance advantages over existing wavefront correctors. These mirrors are developed by coating the free surface of a magnetic fluid with a thin reflective film of nano-particles. The reflective surface of the mirrors can be deformed using a locally applied magnetic field and thus serves as a wavefront corrector. MFDMs have been found particularly suitable for ophthalmic imaging systems where they can be used to compensate for the complex aberrations in the eye that blur the images of the internal parts of the eye. However, their practical implementation in clinical devices is hampered by the lack of effective methods to control the shape of their deformable surface. The research work reported in this thesis presents solutions to the surface shape control problem in a MFDM that will make it possible for such devices to become integral components of retinal imaging AO systems. The first major contribution of this research is the development of an accurate analytical model of the dynamics of the mirror surface shape. The model is developed by analytically solving the coupled system of fluid-magnetic equations that govern the dynamics of the surface shape. The model is presented in state-space form and can be readily used in the development of surface shape control algorithms. The second major contribution of the research work is a novel, innovative design of the MFDM. The design change was prompted by the findings of the analytical work undertaken to develop the model mentioned above and is aimed at linearizing the response of the mirror surface. The proposed design also allows for mirror surface deflections that are many times higher than those provided by.
Download or read book Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems written by Zhizheng Wu and published by Springer Science & Business Media. This book was released on 2012-10-22 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems presents a novel design of wavefront correctors based on magnetic fluid deformable mirrors (MFDM) as well as corresponding control algorithms. The presented wavefront correctors are characterized by their linear, dynamic response. Various mirror surface shape control algorithms are presented along with experimental evaluations of the performance of the resulting adaptive optics systems. Adaptive optics (AO) systems are used in various fields of application to enhance the performance of optical systems, such as imaging, laser, free space optical communication systems, etc. This book is intended for undergraduate and graduate students, professors, engineers, scientists and researchers working on the design of adaptive optics systems and their various emerging fields of application. Zhizheng Wu is an associate professor at Shanghai University, China. Azhar Iqbal is a research associate at the University of Toronto, Canada. Foued Ben Amara is an assistant professor at the University of Toronto, Canada.
Download or read book Adaptive Optics for Industry and Medicine written by Christopher Dainty and published by Imperial College Press. This book was released on 2008 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume presents the very latest developments in non-astronomical adaptive optics. This international workshop, the sixth in a biennial series, was the largest ever held and boasted significant involvement by industry. Adaptive optics is on the verge of being used in many products; indeed, at this meeting, the use of adaptive optics in DVD players was disclosed for the first time. Sample Chapter(s). Liquid Crystal Lenses For Correction Of Presbyopia (586 KB). Contents: Wavefront Correctors and Control: Liquid Crystal Lenses for Correction of Presbyopia (G Li & N Peyghambarian); Woofer-Tweeter Adaptive Optics (T Farrell & C Dainty); Wavefront Sensors: A Fundamental Limit for Wavefront Sensing (C Paterson); Direct Diffractive Image Simulation (A P Maryasov et al.); Adaptive Optics in Vision Science: A Study of Field Aberrations in the Human Eye (A V Goncharov et al.); Characterization of an AO-OCT System (J W Evans et al.); Adaptive Optics in Optical Storage and Microscopy: Commercialization of the Adaptive Scanning Optical Microscope (ASOM) (B Potsaid et al.); Towards Four Dimensional Particle Tracking for Biological Applications (H I Campbell et al.); Adaptive Optics in Lasers: New Results in High Power Lasers Beam Correction (A Kudryashov et al.); Adaptive Optics Control of Solid-State Lasers (W Lubeigt et al.); Adaptive Optics in Communication and Atmospheric Compensation: Fourier Image Sharpness Sensor for Laser Communications (K N Walker & R K Tyson); Adaptive Optics System for a Small Telescope (G Vdovin et al.); and other papers. Readership: Industry- and university-level researchers in optics and laser physics.
Download or read book Adaptive Optics with a Micromachined Membrane Deformable Mirror for High Resolution Retinal Imaging written by Lijun Zhu and published by . This book was released on 1999 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of an Adaptive Optics System for Vision Studies written by Yu Bai and published by . This book was released on 2016 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics (AO) is a technology used to sharpen images through real time compensation of optical aberrations. The adaptive optics was firstly used in astronomical telescopes. Now this technique is widely adopted in fields encompassing physics, chemistry, electronics, and computer science. Particularly in vision science, adaptive optics can compensate the aberrations in the eye such that the information of a diseased eye can be read easily. Though the adaptive optics technology is relatively young, it has been demonstrated for advanced ophthalmoscopy as well as for vision test. In this thesis, a commercially available adaptive optics system was assembled up and tested firstly. Then the adaptive optics system was modified to test an eye model. The eye model consists of a lens and a movable mirror, which can simulate different types of diseased eyes by changing the distance between the mirror and the lens. The diseased eye model introduced aberrations to the system, and the deformable mirror in the adaptive optics system was activated and changed the shape to compensate the aberrations. But the correction range by the deformable mirror is limited. By testing the simple eye model, the working range of the deformable mirror and the wavefront sensor were characterized and determined.
Download or read book Micro deformable Mirrors for Adaptive Optics Applications written by Emily Jo Carr and published by . This book was released on 2006 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infinite dimensional Modelling and Control of a MEMS Deformable Mirror with Applications in Adaptive Optics written by Amir Badkoubeh-Hazave and published by . This book was released on 2015 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Optics in Astronomy written by François Roddier and published by Cambridge University Press. This book was released on 1999-06-17 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics is set to revolutionise the future of astronomy; this is the first book on the subject and is set to become the standard reference.
Download or read book Analysis of Non uniform Gain for Control of a Deformable Mirror in an Adaptive optics System written by Kevin P. Vitayaudom and published by . This book was released on 2008 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book LQG Control of a Deformable Mirror Adaptive Optics System with Time Delayed Measurements written by David J. Anderson and published by . This book was released on 1991 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis proposes a linear quadratic Gaussian (LQG) control law for a ground-based deformable mirror adaptive optics system. The incoming image wavefront is distorted, primarily in phase, due to the turbulent effects of the earth's atmosphere. The adaptive optics system attempts to compensate for the distortion with a deformable mirror. A Hartman wavefront sensor measures the degree of distortion in the image wavefront. The measurements are input to a Kalman filter which estimates the system states. The state estimates are processed by a linear quadratic regulator which generates the appropriate control voltages to apply to the deformable mirror actuators. The dynamics model for the atmospheric phase distortion consists of 14 Zernike coefficient states; each modeled as a first-order linear time-invariant shaping filter driven by zero-mean white Gaussian noise. The dynamics of the deformable mirror are also model as 14 Zernike coefficients with first-order deterministic dynamics. A significant reduction in total wavefront phase distortion is achieved in the presence of time-delayed measurements. Wavefront sensor sampling rate is the major factor limiting system performance. The Multimode Simulation for Optimal Filter Evaluation (MSOFE) software is the performance evaluation tool of choice for this research.
Download or read book Extreme Adaptive Optics Testbed written by J. W. Evans and published by . This book was released on 2005 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have demonstrated that a microelectrical mechanical systems (MEMS) deformable mirror can be flattened to
Download or read book Adaptive Optics Ophthalmologic Systems Using Dual Deformable Mirrors written by and published by . This book was released on 2007 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive Optics (AO) have been increasingly combined with a variety of ophthalmic instruments over the last decade to provide cellular-level, in-vivo images of the eye. The use of MEMS deformable mirrors in these instruments has recently been demonstrated to reduce system size and cost while improving performance. However, currently available MEMS mirrors lack the required range of motion for correcting large ocular aberrations, such as defocus and astigmatism. In order to address this problem, we have developed an AO system architecture that uses two deformable mirrors, in a woofer/tweeter arrangement, with a bimorph mirror as the woofer and a MEMS mirror as the tweeter. This setup provides several advantages, including extended aberration correction range, due to the large stroke of the bimorph mirror, high order aberration correction using the MEMS mirror, and additionally, the ability to ''focus'' through the retina. This AO system architecture is currently being used in four instruments, including an Optical Coherence Tomography (OCT) system and a retinal flood-illuminated imaging system at the UC Davis Medical Center, a Scanning Laser Ophthalmoscope (SLO) at the Doheny Eye Institute, and an OCT system at Indiana University. The design, operation and evaluation of this type of AO system architecture will be presented.
Download or read book The Simplest Test of Target Zone Credibility written by and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
