This paper describes the Rubicon(tm) actuator, discusses its test data and derives from the data the actuator's accuracy function based upon the observed accuracy of long and short stroke motion commands. The accu...
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ISBN:
(纸本)0819437387
This paper describes the Rubicon(tm) actuator, discusses its test data and derives from the data the actuator's accuracy function based upon the observed accuracy of long and short stroke motion commands. The accuracy is described in terms of the rms positioning error (in nanometers) for moves of a given size, regardless of position in the stroke.
By using a binary phase grating, a lens centering system is constructed. In our system, the lens under alignment is mounted on a suitable mechanical axis that can be a spindle of precision lathe. A binary phase gratin...
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ISBN:
(纸本)0819437387
By using a binary phase grating, a lens centering system is constructed. In our system, the lens under alignment is mounted on a suitable mechanical axis that can be a spindle of precision lathe. A binary phase grating is used as a beam splitter. Laser beam after passing through the grating only +/- 1 orders are kept unstop, reflected back by lens surface, recombined by the same grating, and very good contrast interference fringes can be attained. When the lens together with the spindle is rotated, the interference fringes remain motionless only when the lens rotates around its axis of symmetry. If the lens rotates around an axis of asymmetry, the fringes will move. A CCD camera is used to monitor the fringes and transversal error less than a micrometer can be achieved. The interference fringes are very insensitive to vibration and environment. In the paper the theory are presented and the experimental results are given.
Eyepieces are a part of visual optical systems. Because of their wide field of view and long eye-relief, it is difficult to further improve the existing eyepieces using all-refractive surfaces. Since diffractive eleme...
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ISBN:
(纸本)0819437387
Eyepieces are a part of visual optical systems. Because of their wide field of view and long eye-relief, it is difficult to further improve the existing eyepieces using all-refractive surfaces. Since diffractive elements demonstrate unique characteristics: negative dispersion and non-field curvature, the eyepiece design can be improved by using refractive-diffractive hybrid surfaces. In this paper, several design examples using refractive-diffractive hybrid surfaces to design moderate field of view (FOV) eyepieces were studied. Firstly, a design example using a diffractive surface to replace the negative piece in the cement doublet of a conventional Kellner type eyepiece is presented. Then a design example is given by employing two diffractive elements to replace the negative elements used in the conventional symmetrical eyepiece. For the above examples the eyepiece aberration correction techniques were also analyzed.
In Free Gyroscopic Stabilized Seekers, the Primary Minor has the multiple functions of a magnetic rotor, the primary rotating mass and the primary reflector for the optical train. The introduction of rare-earth magnet...
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ISBN:
(纸本)0819437387
In Free Gyroscopic Stabilized Seekers, the Primary Minor has the multiple functions of a magnetic rotor, the primary rotating mass and the primary reflector for the optical train. The introduction of rare-earth magnetic alloys to this class of seeker has provided increased flexibility in materials selection, opto-mechanical design and cost of manufacture. Along with superior magnetic properties, the rare-earth alloy Neodymium-Iron-Boron (NdFeB) comes with the undesirable properties of anisotropic CTE, high susceptibility to corrosion and manufacturing challenges. This paper discusses the opto-mechanical design, structural and optical modeling and analysis of a primary mirror assembly utilizing an NdFeB insert with centrifugal, linear acceleration and thermal loading as well as the optical test results, qualification testing of long-term figure stability and validation of the mechanical/magnetic/opticaldesign model.
作者:
Robinson, DWNASA
Goddard Space Flight Ctr Greenbelt MD 20771 USA
A method of minimizing the optical distortion from gravity sag on a suspended large autocollimating flat mirror has been devised. This method consists of an inverted nine-point Hindle-Mount. A conventional Hindle-Moun...
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ISBN:
(纸本)0819437387
A method of minimizing the optical distortion from gravity sag on a suspended large autocollimating flat mirror has been devised. This method consists of an inverted nine-point Hindle-Mount. A conventional Hindle-Mount is located underneath a sky-viewing mirror and is primarily under compression loads from the weight of the mirror. It is not suitable for the situation where the mirror is viewing the ground, since a mirror would tend to fall out of the mount when in an inverted position. The inverted Hindle-Mount design consists of bonded joints on the backside of the mirror that allow the mirror to be held or suspended above an object to be viewed. This ability is useful in optical setups such as a calibration test where a flat mirror is located above a telescope so that the telescope may view a known optic.
In the latest ten years, great efforts have been taken to miniaturize the biochemical and chemical analysis systems, and many kinds of biochips with functions of biology sample preparing, chemical assay reacting and r...
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ISBN:
(纸本)0819437387
In the latest ten years, great efforts have been taken to miniaturize the biochemical and chemical analysis systems, and many kinds of biochips with functions of biology sample preparing, chemical assay reacting and result detecting, or mixture of some of these functions have been reported. An aspherical micro lens array with large numerous aperture is developed for a biosensor to achieve high fluorescence collection and high sensitivity. The optimized design and fabrication with new organic-inorganic sol-gel materials of micro lens arrays are discussed in this paper. Because of merits of micro size, low cost, facility to reproduce, flexibility to design and multi-channels detection, these elements are suitable to form a compact, multi-channel fluorescence biosensor that can address multiple biology samples simultaneously without loss in detection sensitivity. Packaging and alignment strategies for a sensor consist of micro lens arrays detecting fluorescence labeled DNA assay arrays are also presented, which is promising to be integrated into a micro total analysis system (u-TAS).
作者:
Huegele, VBNASA
George C Marshall Space Flight Ctr SOMTC Huntsville AL 35812 USA
A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have a spherical surface to approximate a parabolic concentrator ...
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ISBN:
(纸本)0819437387
A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have a spherical surface to approximate a parabolic concentrator when combined into the entire 17-foot diameter array. The mirror segments are aluminum hexagons that had the surface diamond turned and quartz coated. The array focuses sunlight reflected from a heliostat to a 4 inch diameter spot containing 8 kilowatts of power at the 15 foot focal point. The derivation of the surface figure for the respective mirror elements is shown. The alignment process of the array is discussed and test results of the system's performance are given.
The numerical calculation of diffraction integrals in systems with aberrations is addressed from the point of view of a new geometrical interpretation of the diffraction phenomena. This interpretation is based on the ...
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ISBN:
(纸本)0819437387
The numerical calculation of diffraction integrals in systems with aberrations is addressed from the point of view of a new geometrical interpretation of the diffraction phenomena. This interpretation is based on the division of the integration domain in semiperiodic zones that isolate the integrand oscillations. Moreover, the critical points of the aperture allow to identify the zones with a net contribution to the diffracted field. With the help of this interpretation it is possible to define methods for calculating the diffraction of a spherical wave incident on an aperture. We study the problems that arise when these methods have to be applied to waves in aberrated systems and we propose a solution based on the analysis of the behavior of the optical path of the wave incident on the exit pupil of the system.
A strategy for optimizing both the on-axis and the off-axis performance of coherently (directly) coupled visual instruments is presented. The strategy draws on the recently published body of data regarding the influen...
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ISBN:
(纸本)0819437387
A strategy for optimizing both the on-axis and the off-axis performance of coherently (directly) coupled visual instruments is presented. The strategy draws on the recently published body of data regarding the influence of various individual Seidel aberration and aberration combinations on subjective contrast sensitivity and resolution tasks, as well as studies on the correlation between subjective image quality and objective instrumental figures of merit. An MTF-based metric allows both optimization and tolerancing to be performed in a coherent manner that is based on experimental results of the effects of aberrations.
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