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.
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.
The recent restructuring of the AXAF program has necessitated a review of the design of the ACIS instrument. In this paper we report on the current status of these design activities. We concentrate on changes to the b...
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ISBN:
(纸本)0819412554
The recent restructuring of the AXAF program has necessitated a review of the design of the ACIS instrument. In this paper we report on the current status of these design activities. We concentrate on changes to the baseline CCD and its impact on aspects such as the operating modes. Also we review changes to the mechanical design with respect to the passive cooling scheme facilitated by the change to a highly eccentric deep earth orbit.
In this experimental work, a new and very compact home made XeCl laser has been used for the ion beam generation by metallic targets. Multiply-charge heavy ion pulses have been extracted by the plasma produced by a fo...
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ISBN:
(纸本)0819410365
In this experimental work, a new and very compact home made XeCl laser has been used for the ion beam generation by metallic targets. Multiply-charge heavy ion pulses have been extracted by the plasma produced by a focused laser beam at relatively low flux (approximately 30 MW/cm2) on Si, Ge, Mg and Zn targets. An output peak current of Si3+ ions of 375 mA has been recorded at an acceleration voltage of 200 v only. The insertion of a variable capacitance between the target holder and the acceleration electrode allowed a self-bunching of the ion beam. Besides, a peak current of 1.4 A of Pb3+ ions was obtained by increasing the laser flux to 86 MW/cm2 and the acceleration voltage to 500 v.
A system has been designed for concentration of an intense parallel beam of X-rays from a synchrotron. The system has two stages. The first stage consists of an array of tapered capillaries which decrease the beam cro...
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ISBN:
(纸本)0819409138
A system has been designed for concentration of an intense parallel beam of X-rays from a synchrotron. The system has two stages. The first stage consists of an array of tapered capillaries which decrease the beam cross section from 2 × 2 mm to about .05 mm and increase the beam divergence to near the critical angle. The second stage has a special asymmetric shape which decreases the beam cross section to 0.001 mm (1 micrometer) and increases the beam divergence to about 10 degrees. Although the optics have been optimized for 10 Kev X-rays, they should give substantial benefit over a range of X-ray energies from 5 - 20 Kev. The intensity gain is calculated to be between 5 × 103 and 105 depending on the transmission losses. The design parameters and the current experience with transmission measurements on prototype components will be reviewed. Questions relating to beam heating and radiation damage will also be discussed.
作者：
Tekippe, v.J.Gould Inc.
Fiber Optics Division 6740 Baymeadow Drive Glen BurnieMD21060 United States
Ironically, many of the passive components used extensively in telecommunications systems today were developed originally for fiber optic sensor systems. While the commercial sensor applications have developed more sl...
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Experimental results to-date will be presented from a developmental effort to a produce a J- band (5.85 - 8.2 GHz) relativistic klystron amplifier (RKA) of the high current Naval Research Laboratory (NRL) genealogy. T...
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ISBN:
(纸本)0819410993
Experimental results to-date will be presented from a developmental effort to a produce a J- band (5.85 - 8.2 GHz) relativistic klystron amplifier (RKA) of the high current Naval Research Laboratory (NRL) genealogy. The nominal experimental parameters of this RKA are: v0 600 kv;I0 2 - 4 kA;Bz 1.5 T;τbeam 300 ns;vin 6.6 GHz;Pin &le 500 kW. Because of the smaller component sizes which accompany this frequency (λ 4.5 cm as compared with λ 30 cm for the bulk of other RKA research efforts), much of the discussion will concentrate on the physical principles, fabrication issues, and experimental pitfalls associated with scaling the RKA design.
With the introduction of the Sarnoff 640 (H) × 480 (v) MOS staring focal plane array (FPA), significant advancements have been made in the operational capabilities and performance of silicon-based infrared (IR) i...
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ISBN:
(纸本)0819409359
With the introduction of the Sarnoff 640 (H) × 480 (v) MOS staring focal plane array (FPA), significant advancements have been made in the operational capabilities and performance of silicon-based infrared (IR) imaging technology. This paper describes the performance of a 640 × 480 PtSi, 3 - 5 μm (MWIR), Stirling cooled camera system with a Minimum Resolvable Temperature (MRT) = 0.03 K (0.02 cycles/mRAD, f/1.5 optics, 300 K background, 30 Hz). Based upon the performance of the Stirling cooled camera, the preliminary specification of a full-Tv resolution platinum silicide (PtSi) radiometer has been developed. The radiometer is optimized for imaging rapid thermal transients. The radiometer design shows promise of following rapid thermal transients from 25 C to 250 C with better than 1% temperature resolution. This performance is achieved utilizing the 640 × 480 FPA integration time control, which provides a commandable dynamic range of 2,500,000:1 with exposure control latency of <16 ms. In other developments, a liquid nitrogen cooled camera with an 8-position filter wheel is described. A low thermal mass packaging approach to assure rapid cool-down in Joule-Thomson Dewars is also presented. The 640 × 480 MOS multiplexer, with its high saturation capacity and low-temperature operation capability, is ideally suited for long-wavelength operation. An advanced PtSi process is being developed toward realization of a longer cut-off, MWIR detector with an operating temperature of 65 - 72 K. For 8 - 12 μm (LWIR) applications, both IrSi and SiGe FPAs are under development. Progress in development in these FPAs is reported.
The DC and low frequency noise characteristics of InGaAs/InP planar separate absorption, grading, charge, and multiplication (SAGCM) avalanche photodiode are reported. These devices have DC gains greater than 100 with...
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A laser design with pulsed vapor generation capability for studying metal vapor lasing in this kind of the apparatus geometry is outlined. The CvL action was obtained at λ = 510.6 and 578.2 nm with specific output po...
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