Topic
Contrast transfer function
About: Contrast transfer function is a research topic. Over the lifetime, 934 publications have been published within this topic receiving 26533 citations.
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TL;DR: In this paper, an on-axis polarization phase shifting digital holographic microscope is constructed to quantitatively measure both the amplitude and phase distributions of a specimen, and the phase aberration can be eliminated by measuring a specimen-free hologram and then fitting the aberration phase with a least square ellipsoidal model to determine the parameters of the system.
9 citations
TL;DR: A contrast transfer function based phase retrieval algorithm that reconstructs the projected thickness of an homogeneous sample using a polychromatic x-ray source and shows excellent quantitative recovery of test samples.
Abstract: We introduce theoretically and demonstrate experimentally a contrast transfer function based phase retrieval algorithm that reconstructs the projected thickness of an homogeneous sample using a polychromatic x-ray source. We show excellent quantitative recovery of test samples in 2D using a synchrotron source with significant harmonic contamination, and in 3D using a laboratory source.
9 citations
TL;DR: An experimental investigation of the optical transfer functions for an X-ray microscope operated in defocus phase-contrast mode and a theoretical model of partially coherent image formation are compared and are found to be in excellent agreement.
9 citations
TL;DR: In this paper, optical transforms from a through focal series of images of amorphous films of Ge were used to measure the spatial frequencies of maximum and minimum phase contrast of a specific 200 kV lEOL electron microscope.
Abstract: Optical transforms from a through focal series of images of amorphous films of Ge were used to measure the spatial frequencies of maximum and minimum phase contrast of a specific 200 kV lEOL electron microscope. This information was used to determine precise values for the spherical aberration coefficient and defect of focus. Under the appropriate conditions of lens excitation the spherical aberration coefficient was found to be as low as 0·94 mm. Other image defects revealed with great precision were associated with astigmatism, beam divergence and specimen drift in the microscope stage. Quantitative examples illustrating these effects are discussed.
9 citations
Patent•
26 Dec 2005TL;DR: In this article, a spherical aberration compensator and deflecting coils are mounted on the front step of an objective front magnetic field lens, and an appropriate deflection ratio is given feedback by evaluating deviation of aberration compensation status generated by image shift of deflection ratios 9a, 9b of the deflection coils.
Abstract: PROBLEM TO BE SOLVED: To enable to easily adjust an electro-optical system of a scanning transmission electron microscope equipped with an aberration compensator. SOLUTION: The scanning transmission electron microscope is equipped with an electron beam source 1, a convergent lens 3, a scanning coil 10, a dark field image detector 16, a bright field image detector 17, an A/D converter 21 and an information processing device 24 or the like. A spherical aberration compensator 7 and deflecting coils 9a, 9b are mounted on a front step of an objective front magnetic field lens 11, a Fourier conversion image is formed from a scanning transmission image obtained by the dark field image detector 16 or the bright field image detector 17, and an appropriate deflection ratio is given feedback by evaluating deviation of aberration compensation status generated by image shift of deflection ratios 9a, 9b of the deflection coils. COPYRIGHT: (C)2007,JPO&INPIT
9 citations