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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 optical system for X-ray microfocusing that consists of a pair of spherical mirrors was developed, which achieved sub-200 nm focusing at an Xray energy of 8 keV.
Abstract: An optical system for X-ray microfocusing that consists of a pair of spherical mirrors has been developed. In grazing incidence optics with spherical (cylindrical) mirrors, focused beam size is generally restricted by spherical aberration. However, the spherical aberration can be corrected by the sequential reflection of two spherical mirrors, and submicrometer beam size can be obtained by total-reflection mirror optics with spherical concave mirrors. A sub-200 nm focusing has been achieved at an X-ray energy of 8 keV.
4 citations
29 Mar 2017
TL;DR: Adaptive Optics as discussed by the authors is a technique that was originally developed in optical astronomy to solve the problem of optical aberrations in microscopy, which produces a distorted wavefront at the focus of the imaging system leading to a non-optimum focal spot, resulting in a decrease in image resolution and a deterioration in image quality.
Abstract: All forms of optical microscopy have the potential to suffer from aberrations due to misalignments in the optical system, local refractive index changes in the sample, or, in many cases, both. Aberrations produce a distorted wavefront at the focus of the imaging system leading to a non-optimum focal spot, resulting in a decrease in image resolution and hence a deterioration in image quality. The problem is particularly prevalent when imaging biological tissue using an optical sectioning microscope where the improved axial resolution over standard wide-field techniques leads the user to image deeper into their sample than ever before. The structure present in the tissue presents complex axial and lateral variations in refractive indices, inhomogeneities that increase as the thickness of tissue the light passes through increases. Adaptive optics, a technique that originated in optical astronomy, poses a powerful solution to the problem. The principle behind adaptive optics involves shaping the wavefront of the incoming light in such a way so as to overcome the distortions imposed by the sample and imaging system. Crucial to the successful implementation of adaptive optics in microscopy is the method used to determine the wavefront correction required. Here we introduce the concepts behind adaptive optics, discuss several approaches that have been taken to implement adaptive optics into microscopy, and finally provide examples of its success when applied to a variety of imaging modalities such as multiphoton microscopy, stimulated emission depletion microscopy, and selective plane illumination microscopy.
4 citations
TL;DR: A new phase-contrast scanning transmission electron microscope (STEM) in which a probe beam including side robes is formed with an amplitude Fresnel zone plate (FZP) and the interference patterns produced by the zero and first order diffracted waves generated by the FZP are detected is developed.
4 citations
TL;DR: By using an operator description, the spectrum of a symmetric two-mirror resonator in the presence of spherical aberration is derived.
Abstract: By using an operator description we derive the spectrum of a symmetric two-mirror resonator in the presence of spherical aberration.
4 citations
TL;DR: In this paper, the authors proposed a method for quantum-phase electron center (QPEC) at the University of Tokyo (UTO), Tokyo, Tokyo 113-8656, Japan.
Abstract: 1. Research & Development Group, Hitachi, Ltd., Hatoyama 350-0395, Japan 2. Center for Emergent Matter Science (CEMS), RIKEN, Wako 351-0198, Japan 3. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan 4. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan 5. Department of Applied Physics and Quantum-Phase Electron Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan
4 citations