Since the invention of transmission electron microscopy (TEM) in 1932 (Z. Physik 78 (1932) 318) engineering improvements have advanced system resolutions to levels that are now limited only by the two fundamental aberrations of electron lenses; spherical and chromatic aberration (Z. Phys. 101 (1936) 593). Since both aberrations scale ...
PubMed
... surface membrane to correct for aberrations. ... less curvature results in less aberration. ... a negative conic constant helps reduce spherical aberration. ...
DTIC Science & Technology
... The goal was to investigate methods to correct aberrations in the ... with entrapped non-neutral electron distributions to correct spherical aberration. ...
... Accession Number : ADA319052. Title : Demonstrating Optical Aberration Correction With a Mems Micro-Mirror Device. ...
... Accession Number : ADA800275. Title : Correction of Spherical Aberration by a Phased Line Source. Corporate Author : AIR ...
To bring cryo electron microscopy (cryoEM) of large biological complexes to atomic resolution, several factors - in both cryoEM image acquisition and 3D reconstruction - that may be neglected at low resolution become significantly limiting. Here we present thorough analyses of four limiting factors: (a) electron-beam tilt, (b) inaccurate determination of ...
... Title : AN OPTIMIZED METHOD FOR CORRECTING FOR SMEARING ABERRATIONS: COMPLEX X-RAY SPECTRA. Corporate ...
The structure of immature and mature HIV-1 particles has been analyzed in detail by cryo electron microscopy, while no such studies have been reported for cellular HIV-1 budding sites. Here, we established a system for studying HIV-1 virus-like particle assembly and release by cryo electron tomography of intact ...
PubMed Central
Higher-order aberrations correction can improve visual performance of human eye to some extent. To evaluate how much visual benefit can be obtained with higher-order aberrations correction we developed an adaptive optics vision simulator (AOVS). Dynamic real time optimized modal compensation was used to implement ...
NASA Astrophysics Data System (ADS)
... for LINUS were corrected for spherical aberrations but due to the lack of detailed knowledge about the lenses their chromatic aberrations could not ...
... possibly due to spherical aberration within the ... same because of longitudinal chromatic aberration. ... Correcting chromatic aberrations using image ...
attention must be given to spherical aberration, which may be corrected with the .... an indication of residual aberration. Significant spherical aberration ...
NASA Website
correct two of the third-order aberrations, typically spherical and coma. .... To correct this spherical aberration, i.e. step 2, simply vary the radius and ...
... to query the DoD laboratory community or ... lens synthetic aperture system built from commercially ... of each aberration correction was qualitatively ...
... of a corrected line source array designed to illuminate a spherical reflecting surface of specified radius R. Spherical aberration is corrected over a ...
... Abstract : A corrective transverse feed system for spherical reflectors was developed to correct spherical aberrations and provide improved aperture ...
... This transverse feed is designed to correct for spherical aberration over an included angle of the sphere of 120 degrees. ...
We describe the aberration correction capabilities of a holographic recording device made of antiferroelectricphase (7.6/70/30) ion-implanted lead lanthanum zirconate titanate. After a review of holographic aberration correction and a description of the device's holographic storage mode, we describe the experiment ...
... 'Greenwich Hour Angle' and declination are corrected for these effects: precession and nutation of the equatorial reference system, aberration and ...
One of the problems that affects the practical use of holographic memory is deterioration of the reproduced images due to aberration in the optical system. The medium must be interchangeable, and hence it is necessary to clarify the influence of aberration in the optical system on the signal quality and perform aberration ...
SUMMARYZernike phase contrast cryo-electron microscopy (ZPC-cryoEM) is an emerging technique which is capable of producing higher image contrast than conventional cryoEM. By combining this technique with advanced image processing methods, we achieved subnanometer resolution for two biological specimens: 2-D bacteriorhodopsin crystal and epsilon15 bacteriophage. For an ...
High performance laser communication systems require adaptive optics based wavefront correction systems to correct aberrations that result from imperfections in optical hardware and atmospheric conditions. Traditionally, deformable membrane mirrors are us...
National Technical Information Service (NTIS)
The authors demonstrate that confocal imaging trajectories can be established in a transmission electron microscope fitted with two spherical aberration correctors. An atomic-scale electron beam, focused by aberration-corrected illumination optics, is directly imaged by a second aberration-corrected system. The initial experiment ...
Energy Citations Database
Most implementations of adaptive optics in microscopes have not employed a wavefront sensor, but have instead used sensorless aberration correction methods. In these systems, the aberration is determined indirectly through the optimisation of a quality metric, such as image intensity. We explain the principles behind this approach and ...
The aberration of a multipole Wien filter for energy-filtered x-ray photoemission electron microscopy was analyzed and the optimized Fourier components of the electric and magnetic fields for the third-order aperture aberration corrections were obtained. It was found that the third-order aperture aberration ...
The development of technology to measure and correct the eye's higher-order aberrations, i.e., those beyond defocus and astigmatism, raises the issue of how much visual benefit can be obtained by providing such correction. We demonstrate improvements in contrast sensitivity and visual acuity in white light and in monochromatic light ...
The Transmission Electron Aberration-corrected Microscope (TEAM) Project For the past several years, five DOE-supported electron beam microscopy efforts, located at Argonne...
Science.gov Websites
... in correcting mounting errors and other types of low order aberrations typically seen in membrane applications. Spherical aberration can be ...
A means is provided for compensating for spherical aberration in charged particle beam devices. The means includes a sextupole positioned between two focusing lenses.
DOEpatents
A novel ultracorrector is outlined which compensates for the primary and secondary first-order chromatic aberrations and all third-order geometrical aberrations of electron optical systems with a straight axis. Owing to the imposed symmetry conditions on the fields and the paraxial fundamental rays, the corrector does not introduce ...
... element is provided which breaks the received ... is aberrated by the ogive shaped window. ... Light homing, Guided missile windows, Laser beams. ...
In this paper we report the use of adaptive optics to correct for sample induced aberrations in optical microscopy, crucially comparing individual pixel-by-pixel correction against a single correction for an entire optical section. Sample induced optical aberrations in slices of rat brain ...
In this paper I discuss several theoretical and practical aspects related to measuring and correcting the chromatic and spherical aberrations of a cathode objective lens as used in Low Energy Electron Microscopy (LEEM) and Photo Electron Emission Microscopy (PEEM) experiments. Special attention is paid to the various components of the cathode objective ...
Higher-order aberration correction in abnormal eyes can result in significant vision improvement, especially in eyes with abnormal corneas. Customized optics such as phase plates and customized contact lenses are one of the most practical, nonsurgical ways to correct these ocular higher-order aberrations. We ...
Future aberration corrected transmission electron microscopes (TEM) will have a strong impact in materials science, since such microscopes yield information on chemical bonding and structure of interfaces, grain boundaries and lattice defects at an atomic level. Beyond this aberration correction offers new ...
This paper is devoted to one of important problems of beam physics: correction of nonlinear harmful aberrations in different kind of beam lines. There are a set of approaches to solving this problem. In this paper we consider an approach based on algebraic description of nonlinear aberrations. In particular, this approach allows to ...
In an electron beam device in which an electron beam is developed and then focused by a lens to a particular spot, there is provided a means for eliminating spherical aberration. A sextupole electromagnetic lens is positioned between two focusing lenses. The interaction of the sextupole with the beam compensates for spherical aberration. (GHT)
A new technique for designing minimum aberration foil lenses is developed based on exact potential solutions. The method is not limited to the paraxial region and is relativistically correct. As an example, the technique is applied to the problem of spherical aberration minimization.
We have developed and tested a method for minimizing static aberrations in adaptive optics systems. In order to correct the static phase aberrations, we need to measure the aberrations through the entire system. We have employed various phase retrieval al...
The parasitic aberrations of 32 magnetic-quadrupole multiplet microbeam-forming systems with different configurations and excitation modes are calculated by using the matrix method. The parasitic aberration correction and the system tolerance are also discussed and analyzed.
It is important to isolate mirror shape accuracy from misalignment to maximize the ability to correct images in the James Webb Space Telescope. In this effort, nodal aberration theory was used to characterize the misalignment- induced aberration fields. T...
-order aberrations, such as patients with keratoconus. The extent to which corrections of larger HO aberrations can
E-print Network
Measurements were made with a single electrostatic quadrupole and spherical aberration noted. Partial correction of this aberration was effected by utilizing a laminated quadrupole, which allows the voltage distribution along the axial length of the quadrupole to be varied. (auth)
We assess the influence of geometric aberrations on the in-plane performance of optical traps by studying the dynamics of trapped colloidal spheres in deliberately distorted holographic optical tweezers. The lateral stiffness of the traps turns out to be insensitive to moderate amounts of coma, astigmatism, and spherical aberration. Moreover holographic ...
We have developed an image processing algorithm that reduces lateral chromatic aberration. It has been implemented in Nikon digital single-lens-reflex cameras and application software. We have developed the aberration detection method which analyzes capture images and detect the aberrations of the image without lens information. ...
The performance of the conventional low-energy CD-SEM is limited by the aberrations inherent in the probe forming lens. Multi-pole correctors are now available which can reduce or eliminate these aberrations. An SEM equipped with such a corrector offers higher spatial resolution and more probe current from a given electron source, and other aspects of the ...
The objective of this project was to demonstrate the use of multiple distributed deformable mirrors (DMs) to improve the performance of optical systems with distributed aberrations. This concept is expected to provide dramatic improvement in the optical performance of systems in applications where the aberrations are distributed along the optical path or ...
Designing and simulating complex magnet systems needed for cooling channels in both neutrino factories and muon colliders requires innovative techniques to correct for both chromatic and spherical aberrations. Optimizing complex systems, such as helical magnets for example, is also difficult but essential. By using COSY INFINITY, a differential algebra ...
Two methods of spherical aberration corrections of an electrostatic gridded lens have been studied with ray tracing simulations. Both methods are based on modifying electrostatic field on the periphery of the lens. In a simplest case such modification is ...
Octupoles may be used to correct the third order spherical aberration of quadrupole transport systems. Crosstalk in the coupling of an octupole placed at a given point causes it to add a term with the wrong sign in the y-channel if it has the right sign i...
Center for Adaptive Optics, and a research contract from Bausch and Lomb. ABSTRACT There is currently aberrations are corrected with an adaptive optics system. All these results suggest that many, though not all to accurately correct it with adaptive optics 3 have moved the wave aberration from an obscure academic ...
The grooved surface of an aberration-corrected holographic model grating is sensed by utilizing the sensing head of a scanning tunneling microscope. The sensing head is mechanically connected to a blazing type stylus for replicating the groove pattern of ...
The design and construction of a double-hexapole aberration corrector has made it possible to build the prototype of a spherical-aberration corrected transmission electron microscope dedicated to high-resolution imaging on the atomic scale. The corrected instrument, a Philips CM200 FEG ST, has an information limit ...
When light time and stellar aberration corrections are both applied to a geometric position vector, the resulting position vector indicates where the target ...
... Section III discusses Zernike Polynomials and their common use in optics. ... III. ZERNIKE POLYNOMIALS IN OPTICAL SYSTEMS ...
... such that the computational intensity required for correcting an aberrated wavefront, becomes simplified over traditional Shack-Hartmann WFS ...
... assess and compare various techniques for compensating for optical distortions in imaging telescopes by adding diffractive optical elements of the ...
aberrations. Spherical, adjustable Rc: Permits first-order correction to match local figure of parabola; allows subaperature placement ...
... Observatory 17 12. Gregorian Corrector Used With Spherical Reflector Antenna to Correct for Spherical Aberrations 18 13. ...
... Color misalignment due to lateral chromatic aberration: If objective used without additional correcting optics, like a compensating eyepiece. ...
Center for Biologics Evaluation and Research (CBER)
... THE NULL TEST LENS WHICH CORRECTS FOR THE PRIMARY MIRROR SPHERICAL ABERRATION WAS USE D IN TESTING FOR ...
... to query the DoD laboratory community or ... AS WE HAVE BUILT IS USEFUL ... EFFICIENCY, LOCALIZED OPTICAL CORRECTION OF WAVEFRONT ...
... The lenses purchased for LINUS were corrected for spherical aberrations but due to the lack of detailed knowledge about the lenses their chromatic ...
Optical aberrations that are due to high-speed turbulence in the aero-optical regime are corrected with optical phase conjugation based on coherent population trapping in sodium vapor. Experimental measurements of an unheated, forced helium jet in air have demonstrated aberration correction by a factor of 7.8 at a ...
Below we briefly describe the differences between the old and new aberration correction algorithms. The previous SPK light time correction algorithms introduce ...
Below we briefly describe the differences between the old and new aberration correction algorithms. The previous SPK light time correction algorithms ...
Chromatic aberration is a form of aberration in color optical devices that produces undesirable color fringes along borders within images. It is becoming a more critical problem these days as digital cameras are getting smaller, while the number of picture elements is increasing. We propose a novel method for detecting and eliminating chromatic ...
A magnetically focused electrostatic mirror is shown to be able to correct the spherical and chromatic aberrations of a probe forming system simultaneously. The probe forming system comprises a uniform magnetic lens and a uniform electrostatic mirror. Previous theoretical investigations showed that the spherical and chromatic ...
Even the best optical microscopes available on the market exhibit chromatic aberrations to some extent. In some types of study, chromatic aberrations of current optics cannot be neglected and a software correction is highly desirable. This paper describes a novel method of chromatic aberration measurement and ...
The achievable resolution of a modern transmission electron microscope (TEM) is mainly limited by the inherent aberrations of the objective lens. Hence, one major goal over the past decade has been the development of aberration correctors to compensate the spherical aberration. Such a correction system is now ...
The influence of proper motions of sources due to Galactic aberration on precession models based on VLBI data is determined. Comparisons of the linear trends in the coordinates of the celestial pole obtained with and without taking into account Galactic aberration indicate that this effect can reach 20 � as per century, which is important for modern ...
In an electron microscope equipped with sextupole correctors the ultimate resolution is limited by the fifth-order spherical aberration of the optical system used to form the electron probe. We have examined the possibilities of using octupoles in order to correct this fifth-order spherical aberration. We find that for an electrostatic ...
By analysis of the dependence of longitudinal spherical aberration on the numerical aperture, it is possible to find such values of the numerical aperture, where spherical aberration is zero. Such values of the numerical aperture are called correction zones. The work theoretically analyses the described problem and equations are given ...
The lens system of the Melbourne Proton Microprobe, MP, consists of four magnetic quadrupole lenses arranged in a configuration known as a Russian antisymmetric quadruplet. The resolution of the microprobe is degraded by spherical aberration of the lens system. The aim of the present work was to correct the spherical aberration and ...
We demonstrate experimentally that correct phase imaging without 2pi ambiguity is obtainable in digital holography by using a multiwavelength approach in the microscope configuration. We describe a general approach for removing chromatic aberrations and for controlling the pixel size of the reconstructed phase image in multiwavelength digital holography ...
A time-of-flight concept that dynamically corrects for chromatic aberration effects in scanning electron microscopes (SEMs) is presented. The method is predicted to reduce the microscope's chromatic aberration by an order of magnitude. The scheme should significantly improve the spatial resolution of low-voltage scanning electron ...
Analysis of induced wavefront aberration after refractive surgery is important in the design of vision correction and the development of visual correction technology. Based on a mathematical model of the anterior corneal surface, the influence of treatment decentration on induced wavefront aberrations was studied ...
The research reveals that there are higher-order aberrations in visual optical systems, and the important factors are higher-order aberrations that affect the quality of vision to further improve. To correct the higher-order aberrations, the aberrations of vision system must be effectively ...
In some adaptive optics systems the aberration is determined not by using a wavefront sensor but by sequential optimization of the adaptive correction element. Efficient schemes for the control of such systems are essential if they are to be effective. A scheme is introduced that permits the efficient measurement of large amplitude wavefront ...
The quantitative analysis of the effect of aberrations in human eye on vision has important clinical value in the correction of aberrations. The wave-front aberrations of human eyes were measured with the Hartmann-Shack wave-front sensor and modulation transfer function (MTF) was computed from the wave-front ...
A binocular adaptive optics visual simulator is presented. The instrument allows for measuring and manipulating ocular aberrations of the two eyes simultaneously, while the subject performs visual testing under binocular vision. An important feature of the apparatus consists on the use of a single correcting device and wavefront sensor. ...
A domestic spherical aberration corrected 300 kV transmission electron microscope named R005, which stands for 0.05 nm resolution, was developed. It has double aberration correctors in probe-forming and image-forming systems for high-resolution scanning transmission electron microscope (STEM) and conventional transmission electron ...
Holographic optical tweezers allow the creation of multiple optical traps in 3D configurations through the use of dynamic diffractive optical elements called spatial light modulators (SLMs). We show that, in addition to controlling traps, the SLM in a holographic tweezers system can be both the principal element of a wavefront sensor and the corrective element in a closed-loop ...
An improved laser correction mirror is disclosed for correcting aberrations in a laser beam wavefront having a rectangular mirror body with a plurality of legs arranged into opposing pairs along the long sides of the mirror body. Vector force pairs are applied by adjustment mechanisms between members of the opposing pairs for bending a ...
Aberration in ultrasound medical imaging is usually modeled by time-delay and amplitude variations concentrated on the transmitting/receiving array. This filter process is here denoted a TDA filter. The TDA filter is an approximation to the physical aberration process, which occurs over an extended part of the human body wall. Estimation of the TDA filter, ...
This article reviews the fundamental principles by which wavefront aberrometers measure ocular aberrations. Three different ways of interpreting aberration measurements are described in terms of wavefront phase, slope, and curvature. Although curvature is the more familiar concept from geometrical optics, the wave optics concept of wavefront phase is more ...
The Solid-State, Heat-Capacity Laser (SSHCL), under development at Lawrence Livermore National Laboratory is a large aperture (100 cm{sup 2}), confocal, unstable resonator requiring near-diffraction-limited beam quality. There are two primary sources of the aberrations in the system: residual, static aberrations from the fabrication of the optical ...
DOE Information Bridge
The Solid-State, Heat-Capacity Laser (SSHCL), under development at Lawrence Livermore National Laboratory (LLNL) is a large aperture (100 cm{sup 2}), confocal, unstable resonator requiring near-diffraction-limited beam quality. There are two primary sources of the aberrations in the system: residual, static aberrations from the fabrication of the optical ...
Spherical aberration limits the ability of a human eye to form a clear image. The amount of Spherical Aberration found in a given eye is different across a population and is actively changing as a function of accommodation, light level, and age. Any attempt made to correct spherical aberration will need to have an ...
of patients with eyes implanted with different IOLs. In these patients, corneal wave- front aberrations were. 1). Because corneal SA is normally positive, implanting this lens should generate a significantPredicting the Optical Performance of Eyes Implanted with IOLs to Correct Spherical Aberration Juan
The mechanisms of the generation of the fifth order aberrations in a sextupole corrected electron optical system are carefully analyzed, and a new principle is presented to compensate the rotationally symmetric part of the fifth order aberration. A numerical simulation shows that the probe radius can be reduced from 0.8 A to about 0.4 ...
Badal Optometer and rotating cylinders are inserted in the AO-OCT to correct large spectacle aberrations such as myopia, hyperopic and astigmatism for ease of clinical use and reduction. Spherical mirrors in the sets of the telescope are rotated orthogonally to reduce aberrations and beam displacement caused by the scanners. This ...
The dynamic correction of aberrations introduced in optical systems have been a widely discussed topic in the past 10 years. Adaptive optics is the most important developed field where the Shack-Hartmann sensors and deformable mirrors are used for the measurement and correction of wavefronts. In this paper, an interferometric set-up ...
A man with an aberrant right coronary artery and haemodynamically important prolapse of the mitral valve was successfully resuscitated. The aberrant right coronary artery was thought to be a possible cause of the cardiopulmonary arrest in this patient. Both lesions were corrected at a single operation.Images
At present transmission electron energy loss spectrum (EELS) analysis is only carried out in dedicated research instruments such as transmission electron microscopes (TEMs) or scanning transmission electron microscopes. This article presents a new design of second-order geometric aberration corrected EELS spectrometer attachment using split plates, which ...
The authors consider the role of mirrors in synchrotron-radiation beamlines and discuss the optical considerations involved in their design. They discuss toroidal, spherical, elliptical, and paraboloidal mirrors in detail with particular attention to their aberration properties. They give a treatment of the sine condition and describe its role in ...
A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized ...
We examine the effects of aberrations induced by a refractive index mismatch on the signal level and resolution of single-photon (1-p) and two-photon (2-p), conventional and confocal scanning microscopes. In particular, we consider the aberrations introduced by an interface between oil/glass and water. Resolution is defined in terms of enclosed ...
In recent years it has become possible to measure and in some instances to correct the high-order aberrations of human eyes. We have investigated the correction of wavefront error of human eyes by using phase plates designed to compensate for that error. The wavefront aberrations of the four eyes of two subjects ...
We discuss the dominant geometrical aberrations of a grazing incidence reflection grating and new techniques which can be used to reduce or eliminate them. Convergent beam geometries and the aberration correction possible with varied groove spacings are e...
A means is provided for compensating for third and higher order aberration in charged particle beam devices. The means includes two sextupoles with an intermediate focusing lens, all positioned between two focusing lenses.
High average power operation of the Mercury Laser induces dynamic aberrations to the laser beam wavefront. Analysis of recent data indicates that up to 4 waves of low order aberration (mainly focus error or power, with spatial resolution
that is not correctable with conventional spectacles or soft contact lenses. Penetrating keratoplasty may induce a largeCharacterizing the Wave Aberration in Eyes with Keratoconus or Penetrating Keratoplasty Using of eyes, namely those with keratoconus (KC) and those having undergone penetrating keratoplasty (PK
Adaptive optics (AO), a mature technology developed for astronomy to compensate for the effects of atmospheric turbulence, can also be used to correct the aberrations of the eye. The classic phoropter is used by ophthalmologists and optometrists to estimate and correct the lower-order aberrations of the eye, ...
. In conclusion, high-speed aero-optical turbulence aberrations at a frequency of 18 kHz have been cor- rected
Refractive surgery corrects lower-order refractive aberrations (sphere and astigmatism), but in many cases it inadvertently creates large higher-order aberrations that can degrade vision. This has prompted the development of new instruments, aberrometers,...
One of the problems associated with building any aberration-corrected electron microscope objective lens lies in the difficulty of obtaining a sufficiently short focal length. A corrector device which can be used with a conventional magnetic objective len...
Correcting spherical and chromatic aberrations in vitro in human eyes provides substantial visual acuity and contrast sensitivity improvements. We found the same improvement in the retinal images using a model eye with/without correction of longitudinal chromatic aberrations (LCAs) and spherical ...
The use of a Zernike-type phase plate in biologic cryo-electron microscopy allows the imaging, without using defocus, of what are predominantly phase objects. It is thought that such phase-plate implementations might result in higher quality images, free from the problems of CTF correction that occur when images must be recorded at extremely high values of ...
Two different methods have been derived and implemented for simulation of multipole imaging systems and aberration correctors. The first method uses an aberration theory for combinations of multipole lenses and deflectors, including primary and secondary aberrations up to the fifth order. A damped least-squares algorithm is used to ...
During the last decade aberration correctors have become a well-accepted tool in high-resolution transmission electron microscopy. The available correctors compensate for the spherical aberration Cs of the imaging system. Recently, for instruments with considerably improved information limit also the off-axial aberrations have ...
A brief history of the development of direct aberration correction in electron microscopy is outlined starting from the famous Scherzer theorem established in 1936. Aberration correction is the long story of many seemingly fruitless efforts to improve the resolution of electron microscopes by compensating for the ...
Control of chromatic aberration through purely optical means is well known. We present a novel optical/digital method of controlling chromatic aberration. The optical/digital system, which incorporates a cubic phase modulation (CPM) plate in the optical system and post processing of the detected image, effectively reduces a system's sensitivity to misfocus ...
The use of hexapole electron-optical elements to correct the spherical aberrations of the objective lenses of a low-voltage scanning electron microscope is investigated. Compared with the conventional quadrupole-octupole correctors, hexapole systems are simpler in design, easier to tune, and less sensitive to manufacturing imperfections and power supply ...
We report on a novel aberration correction technique that uses the sequential combination of two different aberration measurement methods to correct for setup-induced and specimen-induced aberrations. The advantages of both methods are combined and, thus, the measurement time is strongly ...
