An experimental investigation to improve the discrimination of matched filters in character recognition applications

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1972. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.ed

The optical constants of copper measured in vacuum

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1958

Effect of the photographic gamma on hologram reconstructions

Thesis (Ph.D.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1969. Author's M.S. thesis, Effect of the photographic process on the intensity of hologram reconstructions, is also scanned to the same file: Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1966.An expression derived for hologram exposures made along the straight line portion of the H&D curve of a photographic plate gives the first order transmission of a hologram made up of several object points exposed simultaneously and several object points exposed sequentially. This expression is simplified for the case of only object points exposed sequentially (synthetic holograms) and for the case of only object points exposed simultaneously (conventional holograms). Theory and experiments show the effect of the nonlinearity of the photographic process on the contrast of the reconstruction of both synthetic and conventional holograms. An experimental and theoretical study is given to determine how the total amount of light in the reconstructed image depends upon the number of object points if the total amount of light in the object is kept constant. It is shown both theoretically and experimentally that a conventional hologram contains more light in the reconstructed image than a synthetic hologram of the same number of object points. Also, an experimental and theoretical study is given for both synthetic and conventional holograms to determine the ratio of reference beam illuminance to object beam illuminance which maximizes the amount of light in the reconstructed image. It is shown experimentally that for reasonably small hologram exposures, pre-exposing Kodak 649-F plates to an AG-1 flashbulb increases the amount of light in the reconstructed image. It is also shown that for reasonable pre-exposed densities and observed values of gamma, the maximum amount of light is obtained in the reconstruction of a pre-exposed hologram when the hologram has an average density a little less than one. For holograms that are not pre-exposed, the maximum amount of light is obtained in the reconstruction when the average hologram density is about 0.5. Theory and experiment show that for a hologram object of two or more object points, the non-linearity of the holographic process causes reconstructed images in addition to the desired reconstructed image. These undesired reconstructed images are also in addition to the higher order images caused by the non-linearity of the photographic process. A study is made to determine under what conditions these undesired images are bright enough to degrade the desired reconstructed image

The application of the Rayleigh criterion to holographic images

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1966.An experimental technique is presented which correlates the spatial resolution of a holographic image and the numerical aperture or f-number of the hologram producing that image with the Rayleigh criterion. Additional correlation is achieved by comparing the dimensions of a holographic image of a point source, i.e., an Airy disk pattern, with that required for the measured spatial resolution and the Rayleigh limit. The results show that the Rayleigh criterion is not too strict, and that a slightly better resolution capability is realized in a holographic system such as that used in this experiment

Calculations of central intensity in an aberrated ghost image

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.eduThis study deals with a method of examining the intensity distribution produced by a strongly aberrated wavefront (of the order of 100 wavelengths) in the image plane and its near surroundings. Derivation of the intensity distribution by means of numerical integration methods appears impractical due to the rapid variations of the complex amplitude of the optical field in the exit pupil. The mathematical terms are too complex. An alternative approach to finding the distribution of intensity is introduced here; it is based on the correlation of the results obtained from the theory of Asymptotic Expansion with the fringe pattern produced by inserting the lens system into an interferometer. A wavelength of .5μ, together with a f/5 system were used in order to extract the necessary tabulations. 100 waves of optical path difference between the reference sphere and the aberrated wavefront at the edge of the exit pupil were considered. This study is an effort to provide theoretical support for the laboratory practice of estimating the amplitude of the light wave at various points in image space from the fringe free areas observed when the lens is tested in an interferometer. The study was suggested by Prof. R.E. Hopkins

Analysis of 4-beam phase holographic interferometry for geometries characterized by spatially coherent beams

Thesis (M.S.)--University of Rochester. Institute of Optics.In this paper, real-time holographic interferometry is treated as a generalized process using coherent beams without specifically identifying them as "object" or "reference" beams. In this way, the popular but misleading picture that one is comparing a "reconstructed object" with a perturbed real object is avoided, and the analysis is neater, more versatile, and more representative of the actual process. This different view of the holographic process is used to generate a new formulation for the process which, though restricted to two-dimensional phase holograms, permits a considerably more complicated than normal transmission characteristic for the holographic recording medium. Specifically, the characteristic chosen has nonlinear recording properties and retains finite amplitude modulation in addition to the strong phase characteristic. The formulation is then used to analyze the nature of reference fringes in phase holographic interferograms and fringe visibility for both pure-phase and combination phase and amplitude holograms used in coherent interferometry where fringes are nonlocalized

Ellipsometric study of liquid crystal alignment films

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.eduEllipsometry is used to measure thickness and optical constants of thin film alignment layers used in liquid crystal devices. The setup of a Gaertner Ll 19 Ellipsometer is described and an analysis of the physical and optical considerations presented. Sources of errors are analyzed and their effect on results demonstrated. The nature of thin film liquid crystal alignment layers and their influence on liquid crystal tilt angle are explored. The molecular tilt is measured using conoscopic techniques and correlated with thin film alignment layer parameters

Experimental verification of the phase relationship of the straight edge Fresnel diffraction pattern

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.eduAn experimental technique is described for determining the phase relationship of the straight edge Fresnel diffraction pattern. The phase relationship can be determined from Cornu's spiral, but no technique has existed for experimental verification. The method described combines the hologram recording technique of Lelth and Upatnieks with a microdensltometer. The hologram provides a photographic record of a set of interference fringes which are phase modulated by the Fresnel diffraction pattern of the straight edge. By determining the amount of phase modulation it is possible to determine the phase relationship of the straight edge Fresnel diffraction pattern

Computer generated holograms for testing aspheres

Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.eduThe concept of applying computer generated holography to the testing of aspheric surfaces is confirmed and two techniques for extending their practical range of application are presented. The first technique is the use of a best fit sphere based on minimizing the rate of change of a wavefront. The second technique employs spatial filtering concepts to increase the slope of a wavefront generated by a computer hologram. This is accomplished by interfering the two first order wavefronts formed by the computer generated hologram. The new interference pattern can be used as a new hologram which generates a wavefront having twice the phase factor of the original. These concepts have been implemented and used to test a parabolic mirror. The results of the testing confirm the feasibility of the concepts

The theoretical explanation and experimental observation of conical refraction

Thesis (M.S.)--University of Rochester. Institute of Optics. Thesis advisor inferred from acknowledgments. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.ed