Apochromat

About: Apochromat is a research topic. Over the lifetime, 642 publications have been published within this topic receiving 7934 citations.

Fluorescent confocal microscope with chromatic aberration compensation

Abstract: A fluorescent confocal microscope designed for the improvement of optical cutting function and lateral resolution and the improvement of the accuracy of quantitative measurement for a wide visual field. An intermediary optical system, which is arranged between a pair of scanner mirrors and an objective optical system (a pupil projection lens and an objective lens), is of a retrofocustype construction and it has chromatic aberration of magnification tending to cancel chromatic aberration of magnification of the objective optical system for wavelengths of excitation light and fluorescent light. The pupil of the objective lens is relayed to the vicinity of the scanner mirrors by the pupil projection lens and the intermediary optical system. In this case, a pupil magnification β p is selected to satisfy an expression |β p |≦1.

Unipotential electrostatic lenses: Paraxial properties and aberrations of focal length and focal point

Abstract: An experimental study of electrostatic electron lenses as a function of geometrical and electrical parameters is described. The lenses are of the symmetrical three‐electrode unipotential type. The parameters are the thickness of the center electrode and the interelectrode spacing, both relative to the center electrode aperture diameter, and the ratio of lens voltage to cathode voltage. The lens properties are characterized in terms of the focal length and focal distance, and the spherical and chromatic aberrations of these quantities. In general, the principal surfaces of a lens are not plane, and the aberrations of focal length and focal distance are not the same. Expressions are derived relating the focal length and focal distance aberrations to the spherical and chromatic imaging aberration coefficients Cs and Cc, and the magnification aberrations. The advantages of formulating the lens properties in terms of focal length and focal distance and their aberrations, and the usefulness of the data presente...

50-nm-resolution full-field X-ray microscope without chromatic aberration using total-reflection imaging mirrors.

Abstract: X-ray spectromicroscopy with a full-field imaging technique is a powerful method for chemical analysis of heterogeneous complex materials with a nano-scale spatial resolution. For imaging optics, an X-ray reflective optical system has excellent capabilities with highly efficient, achromatic, and long-working-distance properties. An advanced Kirkpatrick–Baez geometry that combines four independent mirrors with elliptic and hyperbolic shapes in both horizontal and vertical directions was developed for this purpose, although the complexity of the system has a limited applicable range. Here, we present an optical system consisting of two monolithic imaging mirrors. Elliptic and hyperbolic shapes were formed on a single substrate to achieve both high resolution and sufficient stability. The mirrors were finished with a ~1-nm shape accuracy using elastic emission machining. The performance was tested at SPring-8 with a photon energy of approximately 10 keV. We could clearly resolve 50-nm features in a Siemens star without chromatic aberration and with high stability over 20 h. We applied this system to X-ray absorption fine structure spectromicroscopy and identified elements and chemical states in specimens of zinc and tungsten micron-size particles.

Chromatic sensor lens configuration

Abstract: A chromatically dispersive lens configuration may be utilized in optical pens for chromatic range sensing. The lens configuration may include a negative power doublet lens and a positive power lens portion. The Abbe numbers of lenses included in the positive power lens portion may be between the Abbe numbers of the two portions of the doublet lens. The relationship between the Abbe numbers of the materials used in two portions of the doublet lens is generally opposite to their relationship as used in standard doublet lenses of similar geometry. The doublet lens may have a negative spherical aberration which effectively cancels a positive spherical aberration that arises in the positive lens portion. In one embodiment all of the lens elements in the lens configuration are spherical lenses. The lens configuration can be implemented with dimensions which fit a standard commercial optical pen, while providing improved range sensing performance.

Handbook of lens design

Abstract: Geometrical Optics Principles. Optical Surfaces, Ray Tracing, and Wavefront Shape Calculation. Thin Lenses and Spherical Mirrors. Systems of Several Lenses and Thick Lenses. Spherical Aberration. Monochromatic Off-Axis Aberrations. Chromatic Aberrations. The Aberration Polynomial. Diffraction in Optical Systems. Computer Evaluation of Optical Systems. Simple Optical Systems and Photographic Lenses. Complex Photographic Lenses. Ophthalmic Lenses. Telescopes and Afocal Systems. Astronomical Telescopes. Microscopes. Projection Systems. Prisms. Optical Design Optimization. Appendix 1: General Bibliography on Lens Design. Appendix 2: Notation and Primary Aberration Coefficients Summary. Appendix 3: Optical Materials.