A differential equation method has been developed for design of reflecting systems which will be completely free of astigmatism. From caustic theory and a generalization of the Coddington equations, a second order dif...
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ISBN:
(纸本)081941249X
A differential equation method has been developed for design of reflecting systems which will be completely free of astigmatism. From caustic theory and a generalization of the Coddington equations, a second order differential equation can be setup to shape a corrective mirror which eliminates all orders of astigmatism in an optical system. The constant optical path length condition is used to shape another mirror in the system to control spherical aberration. Analysis of results of application of this differential equation design approach to a two-mirror anastigmat is presented, which shows its ability to yield a two-mirror system with high performance over a large field of view.
The transfer function theory for large core optical fiber (bare fiber) and fiber cable (LOCAT) reveals a ray's actual interaction with the fiber lightguide. By applying this new tool in a fiber optic instrument de...
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ISBN:
(纸本)081941249X
The transfer function theory for large core optical fiber (bare fiber) and fiber cable (LOCAT) reveals a ray's actual interaction with the fiber lightguide. By applying this new tool in a fiber optic instrument design, we have improved the repeatability and stability of this fiber optic temperature instrument from 4°C to 0.2°C at 1000°C. Several new concepts such as cable bend increments, fiber status, and fiber status stability also are discussed in this paper.
Phase measuring interferometry is well established as the premier measurement technology in support of optical component fabrication. Commercial instruments are available that provide surface measurements over a range...
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ISBN:
(纸本)081941249X
Phase measuring interferometry is well established as the premier measurement technology in support of optical component fabrication. Commercial instruments are available that provide surface measurements over a range of radii and diameters. However, microlithographic lenses have increased in complexity and scale to the point that most commercial instruments fail to provide adequate surface coverage. Most severe is the ability to measure large diameter, convex surfaces. Anticipating the demands of today's microlithographic lens production, Tropel began design and construction of a new class of phase measuring interferometers in 1990. As a catadioptric design, these instruments feature a large spherical mirror to accomplish their purpose. This paper reviews the opticaldesign of the large aperture reflective interferometer (LARI), and various considerations in their construction.
In the first part of this paper, we examine previously used methods for the assessment of the subjective performance of lenses coupled to the eye, we establish the need for a unified means of assessment in terms of vi...
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ISBN:
(纸本)081941249X
In the first part of this paper, we examine previously used methods for the assessment of the subjective performance of lenses coupled to the eye, we establish the need for a unified means of assessment in terms of visual tasks and targets, and we propose such a means. In the second part, we address some common aberration balancing questions, with a view to presenting concrete recommendations for opticaldesign. The balancing questions examined are: defocus and accommodation, accommodation and longitudinal color, spherical aberration and defocus, astigmatism and field curvature, field curvature and accommodation, transverse color and astigmatism, and coma and astigmatism.
For many illumination applications, it is desirable for a laser beam to have a uniform irradiance distribution across its diameter. Refractive and reflective systems for reshaping a laser beam profile have been propos...
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ISBN:
(纸本)081941249X
For many illumination applications, it is desirable for a laser beam to have a uniform irradiance distribution across its diameter. Refractive and reflective systems for reshaping a laser beam profile have been proposed and discussed for many years. One of the refractive systems consisting of two plano-aspherical lenses operates with high efficiency. Recently, a prototype of this two aspherical lens reshaping system has been made from CaF2. The performance of the prototype is presented in this paper. The opticaldesign and analysis of this system also are discussed.
The two monochromators of this instrument (excitation monochromator and emission monochromator) have been designed with a specific optical system which has higher transfer energy. All the parts of this instrument have...
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ISBN:
(纸本)081941249X
The two monochromators of this instrument (excitation monochromator and emission monochromator) have been designed with a specific optical system which has higher transfer energy. All the parts of this instrument have been placed in the inverse plane (33 × 21.5 cm), which makes the instrument compact and installment easy. The design also provides a novel idea to solve the contradiction between system energy and limited power, it only takes a little power to complete most of the fluorescence analyses. An internal microprocessor utilizes chemometric analysis techniques to determine the concentrations of target analyses in a complex chemical matrix. Typical analysis techniques include multivariate linear regression and principal components analysis.
We discuss the problem of how to determine the optimum focus during MTF or similar observerless testing of visual instruments. We review the literature to show that the most commonly employed method, maximization of t...
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ISBN:
(纸本)081941249X
We discuss the problem of how to determine the optimum focus during MTF or similar observerless testing of visual instruments. We review the literature to show that the most commonly employed method, maximization of the response at a single spatial frequency, can lead to very large errors in predicting the visual quality of an instrument. We propose alternative criteria, and examine their behavior through focus and in the presence of aberrations. current data support the assertion that an appropriately defined radius of encircled energy, or an averaged MTF integral, are the best candidates to serve both as general image quality criteria and as a means for determining the optimum focus. We conclude by proposing an experiment that should resolve any remaining questions.
The use of a standard aspheric profile to describe conventional optical elements in lens design programs has advantages such as independent verification of lens system performance by different individuals, ease of int...
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ISBN:
(纸本)081941249X
The use of a standard aspheric profile to describe conventional optical elements in lens design programs has advantages such as independent verification of lens system performance by different individuals, ease of interpretation by different manufacturers, etc. A model of diffractive optical element is proposed for consideration as a standard form to have similar benefits. Diffractive elements are characterized here by (1) the equation of the supporting surface (substrate), and (2) the phase function. The phase function itself consists of two terms: (a) the stigmatic phase term, and (b) the astigmatic phase term. The stigmatic phase term is a rotationally symmetric function and is related to the property of the diffraction element to image free from aberration one axial point onto another, as in holograms, at a specific (reference) wavelength. The astigmatic phase term is an arbitrary function of the space coordinates, it takes several forms: it can impart aspheric deformations (or corrections) to incident wave fronts or it can be used to model different types of gratings.
At HASYLAB the DORIS iii project is almost finished. Recently a decision has been made to use DORIS iii as a dedicated synchrotron radiation source in the future. So many conflicts between the operational requirements...
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ISBN:
(纸本)0819412627
At HASYLAB the DORIS iii project is almost finished. Recently a decision has been made to use DORIS iii as a dedicated synchrotron radiation source in the future. So many conflicts between the operational requirements between synchrotron radiation and high energy physics no longer exist. In the moment nine insertion devices with a total length of 28.3 m are routinely operated in DORIS iii. Two new insertion device developments for DORIS iii are underway. An asymmetric hybrid structure (ASYH) which can be operated in exchange with anyone of the X-ray wigglers will be available by the end of 1993. For place #5, a 4 m long straight section which is presently still free, a hard X-ray wiggler using a 2 T hybrid structure is in the design phase. It is planned to install this device in the second half of 1994. An exciting new opportunity in the decision to use PETRA, a 12 GeV electron storage ring for synchrotron radiation experiments. An undulator beamline is under construction now.
current generation of advanced IC's require sub-half-micron-resolution photolithography over large exposure fields, with device overlay tolerances of less than 100 nanometers. Achieving this performance in high-vo...
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ISBN:
(纸本)0819411604
current generation of advanced IC's require sub-half-micron-resolution photolithography over large exposure fields, with device overlay tolerances of less than 100 nanometers. Achieving this performance in high-volume manufacturing will challenge the focus and overlay control capabilities of optical reduction steppers. This paper presents new metrological approaches to achieving the required focus and overlay control performance. A latent image focus measurement technique is described, which has been used extensively to characterize die levelling performance. To improve overlay capability on back end levels (especially metal), a combined bright field/dark field alignment system has been developed. Data on alignment performance, and optimization of alignment mark design for bright field, will be presented.
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