Th. doct.--Physique expérimentale--Göteborg (Suède)--Chalmers university of technology, Göteborg university, 2003. / Bibliogr. p. 45-50. Annexes.

No description available.

Thesis (M.S.)--University of Michigan, 1957.

Th. doct.--Signal et images--Paris--ENST, 1992. / Bibliogr. p. 18-19.

Call number: LD2668 .T4 1939 G81 / Master of Science

This dissertation investigates a method for extending the measurement range of an optical surface profiling instrument. The instrument examined in these experiments is a computer-controlled phase-modulated interference microscope. Because of its ability to measure surfaces with a high degree of vertical resolution as well as excellent lateral resolution, this instrument is one of the most favorable candidates for determining the microtopography of optical surfaces. However, the data acquired by the instrument are restricted to a finite lateral and vertical range. To overcome this restriction, the feasibility of a new testing technique is explored. By overlapping a series of collinear profiles the limited field of view of this instrument can be increased and profiles that contain longer surface wavelengths can be examined. This dissertation also presents a method to augment both the vertical and horizontal dynamic range of the surface profiler by combining multiple subapertures and two-wavelength techniques. The theory, algorithms, error sources, and limitations encountered when concatenating a number of profiles are presented. In particular, the effects of accumulated piston and tilt errors on a measurement are explored. Some practical considerations for implementation and integration into an existing system are presented. Experimental findings and results of Monte Carlo simulations are also studied to explain the effects of random noise, lateral position errors, and defocus across the CCD array on measurement results. These results indicate the extent to which the field of view of the profiler may be augmented. A review of current methods of measuring surface topography is included, to provide for a more coherent text, along with a summary of pertinent measurement parameters for surface characterization. This work concludes with recommendations for future work that would make subaperture-testing techniques more reliable for measuring the microsurface structure of a material over an extended region.

No description available.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: vacuum; shape and deformation measurement; MEMS; vibrometry; scanning white light; Interferometry; thermal; vibration. Includes bibliographical references (136-139 leaves ).

Thesis (Ph. D.)--Oregon Graduate Center, 1976.

Ph.D. / Applied Physics / This work was undertaken to determine the feasibility of using a field ionization (FI) source to produce fine focus ion beams. Operating parameters for a FI source have been measured and a source sensitivity of ~ 5 x 10[superscript-5] A sr[superscript -1] torr[superscript -1] was found for both H[subscript 2] and Ar at 77 K. The source is gas phase, differentially pumped with typical operating pressures of 1 - 30 x 10[superscript -3] torr at 77 K, resulting in a maximum source brightness ≈ 10[superscript 8] A cm[superscript -2] sr[superscript -1] and angular intensity of ≈ 10[superscript -6] A sr[superscript -1] with beam energies of 10 - 20 keV. Angular distributions were measured and found to be uniform near θ = 0°, with the beam confined to ±20°. A scanning ion microscope (SIM) was built to further evaluate the source. The SIM has been operated with currents on the specimen of 10[superscript -11] – 10[superscript -10 amperes in the secondary electron mode with contrast provided primarily by the sec (θ) dependence of the secondary electron yield, where θ is the angle between the beam and the specimen normal. Secondary electrons are detected and amplified with a channeltron multiplier and images generated as with a conventional SEM. All electrostatic optics are used in a doublet arrangement, and with this configuration current is independent of working distance which is 3 - 4 cm. A current of 5 x 10[superscript -11] A was focused into a spot of ≈ 6500 Å with H[subscript 2] gas, the resolution being limited by chromatic aberration caused by the ≈ 4 eV energy spread of the two component (H[superscript +] H[superscript +, subscript 2]) beam. Signal to noise ratio measurements on the source made at the specimen position show that the bulk of the noise power spectrum falls below f = 30 Hz.