No description available.

Thesis (M.S.)--Ohio University, August, 1995. / Title from PDF t.p.

Inaug.-diss.--Leipzig. / Lebenslauf.

In order to study the detailed spectral intensity distribution of light reflected from a solid-gas interface, the extinction theorem in optics is extended to include an absorbing medium and the thermal motion of the gas molecules near the interface. The theoretical spectral intensity distribution in the region of anomalous dispersion is found to be strongly modified compared to that predicted by existing theory. An important consequence of this theory in the line shapes of the reflected light is the possibility of using recently developed saturation spectroscopic techniques to study atoms and molecules near surfaces. In order to investigate the feasibility of these new techniques for obtaining solid-gas molecule interaction potentials, models of solid-gas interfaces were studied with and without interactions of the type 1/zP (p = 2,3,4), where z is the distance between gas molecules and solid surface. A marked difference in the line shapes of the reflected light among the possible interactions suggests that the forms of interaction at the interface can be measured using known techniques. Furthermore, the possibility of measuring the flow of gas near walls where currently available laser-Doppler anemometers can not spatially reach is investigated. It is shown that the shift and width of the numerically calculated line shape of the reflected light in our model flow is directly related to the mean and the fluctuating velocity fields respectively.

No description available.

The design, construction and details of operation of an instrument for measuring Bidirectional Scattering Distribution Functions (BSDF) {i.e., Bidirectional Reflection Distribution Functions (BRDF) and Bidirectional Transmission Distribution Functions (BTDF)} at four wavelengths from the visible to the far infrared (FIR) are presented. Hardware, software, theory, calibration, accuracy and performance are all addressed. The four major interacting subsystems--optical, electronic, mechanical and computer--are discussed in various degrees of detail. A BASIC language control program for running the system via the Z-80 microprocessor is included in the appendix. The origin of BRDF is traced, and a brief theoretical summary examines it from both a physical optics and a radiometric point of view. Modeling is performed to determine the effect of large radiometer collecting apertures on accuracy. Dynamic range and resolution are determined from experimental and theoretical considerations. Finally, new measurements of Martin Black at 118.8 (mu)m are presented along with measurements at 0.6328, 3.39 and 10.6 (mu)m. The FIR BRDF measurements covered 6 orders of magnitude and values as low as 6 x 10('-4) sr('-1) have been recorded.

Unobscured reflective optical systems can be more transmissive and of higher diffraction quality than classical systems. Unobscured systems are generated by decentering symmetric systems, tilting elements to correct coma or astigmatism along a real ray, or by cross-tilting elements to control astigmatism. Such a system of relatively high quality may be further corrected with a general spline surface. For spline surfaces, optical aberration coefficients are undefined. This study developed real ray analysis and design techniques for general optical systems. A decentered symmetric system with a field correcting spline surface was designed. The optical design program ACCOS V was used for most design and analysis tasks. Design and analysis of general systems are considered first. Basic system quantities of image location, scaling, and irradiation are defined with real rays. Spline surfaces are discussed with special emphasis on features important in optical design. Real ray analytical techniques of composite spot diagrams across the image, footprints on spline surfaces, wavefront aperture maps, and spline surface maps are described. The use of these tools in general system design procedures is discussed. Standard telescope objectives of f/8.5 were considered as base designs for systems with spline surfaces. A spline surface was added to the decentered Schmidt-Cassegrain. Optimization yielded diffraction-limited performance across a 0.85 degree square field. The spline system was compared to the Galileo spacecraft narrow angle lens and a three-mirror decentered design. It had a far wider field than the Galileo but at a lower quality. Diffraction quality was better than that of the three-mirror system. Simple tolerances were considered for the spline system. The allowable effect of a thermal gradient was estimated by bending the reference axis. Decentration and figure tolerances for the spline were commensurate with classical surfaces. Techniques presented were shown to be useful for design and analysis of general systems. Spline surfaces were found to be useful in optimization of such systems. This work was supported by the Director's Discretionary Fund, Jet Propulsion Laboratory, California Institute of Technology.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 166-169).

No description available.

No description available.