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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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Dual focus diffractive optical element with extended depth of focus
Optical Review, 2014A dual focus property and an extended depth of focus were verified by a new type of diffractive lens displaying on liquid crystal on silicon (LCoS) devices. This type of lens is useful to read information on multilayer optical discs and tilted discs. The radial undulation of the phase groove on the diffractive lens gave the dual focus nature. The focal
Katsuhiro Uno, Isao Shimizu
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Through-focus scanning optical microscopy (TSOM) with adaptive optics
Metrology, Inspection, and Process Control for Microlithography XXXII, 2018Through-focus optical microscopy (TSOM) with nanometer-scale lateral and vertical sensitivity levels matching those of scanning electron microscopy has been demonstrated to be useful both for 3D inspections and metrology assessments. In 2014, funded by two private companies (Nextin/Samsung Electronics) and the Korea Evaluation Institute of Industrial ...
Chris Park +3 more
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Holographic Optical Element For A Dual Focus Optical Head
Diffractive Optics and Micro-Optics, 1998A high density optical disk format named DVD adopts a 0.6 mm disk to simultaneously use a high numerical aperture (NA) lens and gain tolerance of disk tilt.1 Because of the immense popularity of the CD format, it is important to playback the current widely used Compact Discs (CDs) on DVD format players.
Yoshiaki Komma +5 more
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Quasi In-Focus Optical Coherence Tomography
Japanese Journal of Applied Physics, 2004We propose here a unique method for in-focus imaging over the entire cross-sectional area of interest. This is the so-called quasi in-focus optical coherence tomography (OCT) or multiple OCT in which OCT images are obtained by shifting the focal plane of an objective, followed by piling up of these OCT images.
Masato Ohmi +3 more
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All-optical extended focus imaging system
SPIE Proceedings, 2003A lens in conjunction with a multiplexed set of Fresnel lenses (FL) can significantly reduce the sensitivity of an optical system to defocus aberrations. Each FL is considered as a corrective lens with a slightly different focal length. Thus for a fixed detector plane, there is a set of object planes for which the composite lens provides perfect ...
Eyal B. Eliezer +3 more
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Optical antennas focus in on biology
Nature Photonics, 2008Biological processes often involve multimolecular interactions on a nanometre scale or at very large molecular concentrations, making them difficult to visualize. Optical antennas have the potential to become powerful tools for nanobioimaging by enhancing optical fields on this tiny scale.
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