Modelling of influence of spherical aberration coefficients on depth of focus of optical systems

2017 ◽  
Author(s):  
Petr Pokorný ◽  
Filip Šmejkal ◽  
Pavel Kulmon ◽  
Antonín Mikš ◽  
Jiří Novák ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Optical Systems ◽  
Depth Of Focus

Dependence of depth of focus on spherical aberration of optical systems

2016 ◽  
Vol 55 (22) ◽  
pp. 5931 ◽  
Author(s):  
Antonín Mikš ◽  
Jiří Novák
Keyword(s):  
Spherical Aberration ◽  
Optical Systems ◽  
Depth Of Focus

New apodizers that arbitrarily decrease sensitivity to defocusing or to the variation of spherical aberration

1988 ◽  
Vol 66 (10) ◽  
pp. 878-882
Author(s):  
Richard Boivin
Keyword(s):  
Spherical Aberration ◽  
The Other ◽  
Optical Systems ◽  
Depth Of Focus ◽  
Rotationally Symmetric

Two families of pupil amplitude filters, or apodizers, are devised for rotationally symmetric optical systems. One type of apodizer, pertaining to systems with circular pupils, arbitrarily reduces their sensitivity to the variation of primary spherical aberration, when this is combined with defocusing to optimally compensate for the aberration. The other type of apodizer, pertaining to systems with slit pupils, arbitrarily extends their depth of focus.

Atomic Resolution in Crystal Aperture Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 236-237
Author(s):  
J T Fourie
Keyword(s):  
Optical System ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Transmission Function ◽  
Optical Systems ◽  
Bragg Angle ◽  
Electron Optical System ◽  
Intimate Contact ◽  
Diffraction Effects ◽  
Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

Modelling the effects of secondary spherical aberration on refractive error, image quality and depth of focus

2014 ◽  
Vol 35 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Renfeng Xu ◽  
Arthur Bradley ◽  
Norberto López Gil ◽  
Larry N. Thibos
Keyword(s):  
Image Quality ◽  
Refractive Error ◽  
Spherical Aberration ◽  
Depth Of Focus

Relationship between Induced Spherical Aberration and Depth of Focus after Hyperopic LASIK in Presbyopic Patients

Ophthalmology ◽  
2015 ◽  
Vol 122 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Benjamin Leray ◽  
Myriam Cassagne ◽  
Vincent Soler ◽  
Eloy A. Villegas ◽  
Claire Triozon ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Depth Of Focus

Depth of focus analysis of optical systems using tunable aperture stops with a moderate level of absorption

2014 ◽  
Vol 53 (28) ◽  
pp. 6508 ◽  
Author(s):  
Daniel Pätz ◽  
Tobias Deutschmann ◽  
Egbert Oesterschulze ◽  
Stefan Sinzinger
Keyword(s):  
Moderate Level ◽  
Optical Systems ◽  
Depth Of Focus ◽  
Focus Analysis
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