Thesis (Ph. D.)--York University, 2001. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 120-122). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ67892.

Infrared interferometric systems using a CO₂ laser operating at a wavelength of 10.6 μm have been investigated. The purpose of infrared interferometry is to test (1) optical components required for high energy laser systems such as infrared transmitting materials and diamond-turned metal mirrors, (2) unpolished rough surface optics during the early stages of fabrication, and (3) deep aspherics and other optics of nonconventional surface figures. The physical principles behind longer wavelength interferometry are as follows. First, the specular component of scattered light increases with increasing wavelength for randomly rough surfaces. Second, the aspheric departure from the best fit reference sphere (in units of probing wavelength) is reduced. This reduced sensitivity gives us a manageable number of fringes in the interferogram of deep aspherics. Specific systems developed in this work are the infrared laser unequal path interferometer (IRLUPI), the IRLUPI with infrared computer generated hologram (IRCGH), the infrared common path interferometers such as the infrared point diffraction interferometer (IRPDI), and the infrared scatterplate interferometer (IRSPI). The above interferometers produce interferograms of equal optical path difference (OPD). Other types of common path interferometers which provide interferograms of differential OPD (or slope) are also developed. They are the infrared lateral shearing interferometers (IRLSI); a germanium plane parallel plate, the Ronchi ruling, and the double grating lateral shearing interferometer. A pyroelectric vidicon (PEV) has been employed as an AC infrared detector with proper intensity modulation techniques. Chopping, panning, and phase variation of the interferogram modulate the interference pattern effectively for various types of interferometers. Germanium and zinc selenide optics are used for lenses and beamsplitters. A He-Ne gas laser is installed parallel to the CO₂ beam for the ease of initial alignment. Many test interferograms are shown using each interferometer. The statistical analysis and experimental verification of the relationship between fringe contrast and rms surface roughness enabled us to have noncontact measurement of surface roughness interferometrically. This result was used for a series of tests for the unpolished large diameter off-axis parabolic mirror during the preliminary fabrication stage. Some interesting topics are included for future investigation to fulfill the growing demand for versatility in interferometry.

No description available.

No description available.

Thesis (Ph.D.)-- University of Adelaide, Mawson Institute, 1978.

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 83-85).

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis--Purdue University. / Vita. Includes bibliographical references.

No description available.

This dissertation is an experimental study of a novel type of interferometry based on the generation of Second Harmonic (SH) light. In this work interferometers are described in which an interference pattern arises when two SH waves are superimposed. These waves come from doubling the fundamental frequency of a laser by means of non-linear crystals. Three interferometers are described that have different applications according to their sensitivity to detect wavefront distortions. One interferometer has low sensitivity and is useful in the contouring of refractive objects that produce large wavefront distortions of the order of hundreds of visible wavelengths. The other two interferometers have high sensitivity and one of them is capable of detecting wavefront distortions as small as 1/20 of wavelength. Special emphasis is placed on development of the first interferometer which is a real-time, common-path, self-referencing interferometer that yields interferograms in the visible. The interferometer is based on the fact that a SH wavefront generated under PM conditions is a faithful replica of the laser wavefront. The two interfering SH wavefronts are produced one before and the other after the object under study, and by virtue of its chromatism, they are very slightly different. Consequently, very low density fringes are produced upon their superposition. In this application, noncritically phase matched crystals perform best, and we have found that Y-cut LiNbO₃ crystals configured for surface acousto-optic applications are very convenient. The conversion efficiencies are very low (of the order of 10⁻⁵) consequently optical damage to the LiNbO₃ due to the SH is no problem. The crystals are phase matched by controlling their temperature and are used with a repetitively pulsed Nd:Yag laser operating at 1.06 μm. The chief limitations of this interferometer come from practical considerations in imaging objects with high spatial frequencies that reduce the contrast of the interferograms. The high sensitivity interferometers make use of the changes of phase and amplitude induced in the SH wavefront by the phase mismatch of angle tuned crystals to provide information. The interferometers are directly sensitive to small wavefront tilts and do not require additional reference wavefronts.