Patent
Methods and apparatus for wavefront manipulations and improved 3-d measurements
TLDR
In this article, the phase and surface topography measurements by wavefront propagation and refocusing, using virtual wave front propagation based on solutions of Maxwell's equations are described, and applied to Integrated Circuit inspection, to improve overlay measurement techniques, by improving contrast or by 3D imaging, in single shot imaging.Abstract:
Methods and apparatus to perform wavefront analysis, including phase and amplitude information, and 3D measurements in optical systems, and in particular those based on analyzing the output of an intermediate plane, such as an image plane, of an optical system. Measurement of surface topography in the presence of thin film coatings, or of the individual layers of a multilayered structure is described.. Multi-wavelength analysis in combination with phase and amplitude mapping is utilized. Methods of improving phase and surface topography measurements by wavefront propagation and refocusing, using virtual wavefront propagation based on solutions of Maxwell's equations are described. Reduction of coherence noise in optical imaging systems is achieved by such phase manipulation methods, or by methods utilizing a combination of wideband and coherent sources. The methods are applied to Integrated Circuit inspection, to improve overlay measurement techniques, by improving contrast or by 3-D imaging, in single shot imaging.read more
Citations
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Patent
Method and system for measuring a surface of an object comprising different structures using low-coherence interferometry
TL;DR: In this paper, a method for measuring a surface of an object (17) comprising at least one structure (41, 42) using low-coherence optical interferometry is described.
Patent
Device, system and method for modulating light using a phase light modulator and a spatial light modulator
Perkins Michael,Kiers David +1 more
TL;DR: In this paper, a phase light modulator (PLM) and a spatial light modulators (SLM) are used to generate a target-source wave at the PLM, based on a free space transfer function between the SLM and the image plane and the target-destination wave.
Patent
Ultra-high-speed, high-precision, three-dimensional refractive index measurement method and device using wavefront shaper
TL;DR: In this article, an ultra-high-speed, high-precision, three-dimensional refractive index measurement method and device using a wavefront shaper are disclosed, which can comprise the steps of changing the irradiation angle and/or a wave front pattern of incident light beams so as to make the light beams incident to a sample, by using the wave front shaper; measuring, according to at least one of the incident light beam, a two-dimensional optical field having passed through the sample by using an interferometer; and acquiring a three dimensional image through the information
Patent
Height measuring method for three dimensional shape measuring device
Joong Ki Jeong,Deok-Hwa Hong +1 more
TL;DR: In this paper, a method of measuring a height of 3-dimensional shape measurement apparatus includes irradiating a first grid pattern light from a plurality of first lighting devices and a second grid pattern image corresponding to the second grid light, generating combined pattern images by combining the first and second pattern images obtained from the first-and second-lighting devices adjacent to each other, and calculating the height of the target object according to a combined equivalent wavelength of the combined patterns.
Patent
3 method for removing moire pattern noise in a treee-dimensional shape measuring microscope
TL;DR: In this article, a method of removing a moire pattern noise from a 3D shape measurement microscope is presented, which is capable of inhibiting and weakening the generation of unexpected moire patterns in a three-dimensional shape measurement microscopy and removing and reducing a noise caused by the pattern, while accurately measuring the shape of a subject.
References
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Patent
Methods and apparatus for splitting, imaging, and measuring wavefronts in interferometry
James E. Millerd,Neal Brock +1 more
TL;DR: In this article, a wavefront-splitting element splits the combined wavefront into a plurality of sub-wavefronts in such a way that each of the sub wavefronts is substantially contiguous with at least one other subwavefront.
Patent
System and method for generating digital images of a microscope slide
TL;DR: In this paper, an improved system and method for obtaining images of a microscope slide are provided, which includes an optical sensor that is tilted relative to the focal plane of a scanning camera.
Patent
Sequential wavefront sensor
Wei Su,Yan Zhou,Qing Chun Zhao +2 more
TL;DR: In this article, the authors proposed a method for auto-focusing and/or auto-astigmatism-correction, which consists of sequentially projecting a number of subwavefronts around an annular ring of a wavefront to a sub-wavefront focusing lens and a detector, calculating the centroid of focused light spot from each sub wavefront, adjusting the focus and or astigmatism of the optical imaging system before the wavefront sensor.
Journal ArticleDOI
Measurement of the Entropy of an Image with Application to Image Focusing
TL;DR: This work has derived empirically a simple approximation formula for the entropy of images, and was able to utilize an existing TV optical nonlinear component which performed the analogue calculation of the formula at TV speed.
Patent
Multiparallel three dimensional optical microscopy system
TL;DR: In this paper, a plurality of image detectors is arranged with respect to an objective lense to divide the light travelling through the objective lens to the detectors into channels such that each channel is registered with a respective detector.