Simulating optical system performance with three-dimensional scenes

2015 ◽  
Author(s):  
William J. Duncan ◽  
Jim Schwiegerling
Keyword(s):  
Optical System ◽  
System Performance ◽  
Three Dimensional

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.

Hybrid optical system for three-dimensional shape acquisition

2013 ◽  
Vol 52 (16) ◽  
pp. 3680
Author(s):  
In Yeop Jang ◽  
Min Ki Park ◽  
Kwan H. Lee
Keyword(s):  
Optical System ◽  
Three Dimensional ◽  
Shape Acquisition ◽  
Dimensional Shape ◽  
Three Dimensional Shape

Measurement of Three Dimensional Position of Particles by Single CCD Image Including Lens Aberration

2003 ◽  
Author(s):  
Hironobu Ueki ◽  
Masahiro Ishida ◽  
Daisaku Sakaguchi ◽  
Manabu Tokumoto
Keyword(s):  
Correlation Coefficient ◽  
Optical System ◽  
Cross Correlation ◽  
Particle Image ◽  
Three Dimensional ◽  
Transformation Function ◽  
Flow Measurements ◽  
Measuring Volume ◽  
Ccd Sensor ◽  
Ccd Image

A new technique using a single CCD image through a lens system with large aberration is proposed in the present study for measurement of the three dimensional position of particles, in which a thick laser light source and a forward-scattering light from particles are processed. This optical system could be very compact and applicable to various flow measurements. The particle image detected by a CCD sensor is distorted in the present system due to lens aberrations. A transformation function of the optical system, which is the relationship between the reference particle with unit luminosity in the measuring volume and the corresponding distorted particle image detected by a CCD sensor through symmetric-convex lenses, is constructed theoretically based on the image formation optics of small particles. In order to obtain a high accuracy in the measurement, it is important to remove the background noise and the light intensity non-uniformity in the measuring volume from the CCD particle image by using a low-pass filtering technique based on the FFT analysis. By calculating the cross-correlation coefficient between the measured particle image and the data base images prepared by the above transformation function, the three dimensional position of the particle is determined as the position at which the largest cross-correlation coefficient is obtained. It is verified experimentally that this compact measuring system is useful for measurement of the three dimensional position of the particle with a good accuracy.

Simulation and analysis of optical imaging systems including real freeform components

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Johannes Stock ◽  
Matthias Beier ◽  
Johannes Hartung ◽  
Sebastian Merx ◽  
Herbert Gross
Keyword(s):  
Experimental Data ◽  
Spatial Frequency ◽  
Optical System ◽  
System Performance ◽  
Imaging Systems ◽  
Optical Surfaces ◽  
Surface Imperfections ◽  
Performance Predictions ◽  
Alignment Errors ◽  
Holistic Description

Abstract In recent years, the precision of the manufacturing process for optical surfaces has improved tremendously. As a result, freefrom surfaces have become more attractive options for imaging applications with increased accuracy requirements. However, with regards the integration into an optical system, performance is often limited due to surface imperfections, such as mid-spatial frequency errors and alignment errors. This demonstrates the need for a more holistic description of systems, including multiple freeform components, which enable performance predictions based on the system as a whole. In this work, a solution for such a simulation is presented and verified by a comparison with the experimental data. This procedure not only predicts system performance but also supports tolerancing and easier alignment.

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