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Focus Sensing Optical Profilometer
SPIE Proceedings, 1989Abstract A high sensitivity focus sensing configuration is employed in the construction of an accurateoptical profilometer. The system is analyzed theoretically and experimental investigation indicates a sensitivity better than 3nm with a linear dynamic range of 50pm.
Andrei Brunfeld +2 more
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Optical generation of focus wave modes
Journal of the Optical Society of America A, 2000Localized wave solutions of free-space wave equation can be used in numerous applications where the localized transmission of electromagnetic energy is of major importance. However, an optical implementation of localized wave fields has not been accomplished yet, except for an ultrashort version of the Bessel beams or the so called Bessel-X pulses.
K, Reivelt, P, Saari
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Variable-focus liquid-filled optical lens
Applied Optics, 1993A variable-focus liquid-filled optical lens consists of a solid plate, a ring spacer, and an elastic film; a liquid fills this lens-shaped container. One varies the focus by changing the liquid volume in the lens. The lens shape calculated theoretically is a paraboloid. However, it is approximately a sphere near the central area. The deformation of the
N, Sugiura, S, Morita
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Focus-wavelength encoded optical profilometer
Optics Communications, 1984Abstract An optical profilometer is presented working on the principle of focus multiplexing by wavelength encoding. Decoding is performed by lateral dispersion. A detector array shows up a signal distribution whose features accurately monitor the surface position of the sample under test.
G Molesini +3 more
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Telecentric optics for focus analysis
IEEE Transactions on Pattern Analysis and Machine Intelligence, 1997Magnification variations due to changes in focus setting pose problems for vision techniques, such as, depth from focus and defocus. The magnification of a conventional lens can be made invariant to defocus by simply adding an aperture at an analytically derived location. The resulting optical configuration is called "telecentric".
M. Watanabe, S.K. Nayar
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Focus vernier for optical lithography
SPIE Proceedings, 1993As the depth of focus of optical steppers grows smaller, it becomes more important to determine the position of best focus accurately and quickly. This paper describes the use of phase-shifted mask technology to form a focus vernier: a phase pattern on the stepper reticle which, when imaged in resist, can give both the magnitude and the direction of ...
William H. Arnold +3 more
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Accurate shape from focus based on focus adjustment in optical microscopy
Microscopy Research and Technique, 2008AbstractOptical microscopy allows a magnified view of the sample while decreasing the depth of focus. Although the acquired images from limited depth of field have both blurred and focused regions, they can provide depth information. The technique to estimate the depth and 3D shape of an object from the images of the same sample obtained at different ...
Seong-O, Shim +2 more
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Focus wave modes in optical parametric generators
Optics Letters, 2002It is shown that in the paraxial approximation the conditions for noncollinear phase matching for three-wave parametric interaction in a nonlinear crystal coincide with the conditions for generation of focus wave modes. As a result, the creation of broadband localized optical fields (pulsed beams without diffraction and dispersion spreading) inside the
S, Orlov, A, Piskarskas, A, Stabinis
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High-dynamic-range cascaded-focus optical limiter
Optics Letters, 2000We report experimental results of using an f/5 , cascaded-focus optical geometry for a high-dynamic-range optical limiter. The device consists of a 2-cm-thick CS(2) cell at the first focus and a reverse saturable-absorber dye in a thin cell (0.1 mm) at the second focus.
F E, Hernãândez +3 more
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