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MASTER: Millimetre and sub-millimetre triple hEterodyne receiver

AIP conference Proceedings 2002年第1期616卷 123-125页

作者： E. S. Battistelli G. Boella F. Cavaliere M. Gervasi A. Passerini G. Sironi M. Zannoni D. Andreone L. Brunetti v. Lacquaniti S. Maggi R. Steni E. Natale G. Tofani E. Bava U. Pisani J. R. Thorpe M. De Petris 1Università degli Studi di Milano Bicocca-Milan-Italy 2Istituto Elettrotecnico Nazionale Galileo Ferraris-Turin-Italy 3Osservatorio Astrofisico di Arcetri-Florence-Italy 4Department of Electronic-Politecnico-Milan-Italy 5Department of Electronic-Politecnico-Turin-Italy 6Department of Electronic and Electrical Engineering-University of Leeds-Leeds-United Kingdom 7Department of Physics-University La Sapienza-Rome-Italy

We will describe a system of three heterodyne receivers. Its mixers are based on SIS tunnel junctions which allow a very sensible downconversion of the detectable signal from 94 GHz, 225 GHz and 345 GHz to 1.5 GHz. This will allow the detection of molecular rotational transition lines from diffuse molecular clouds. current status of a 94 GHz receiver, prototype of MASTER, will also be described. Technical design and cryogenic problems solution will be shown and we will focus our attention on the optical coupling technique based on gaussian beam analysis.

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Supersonic plasma jets formed by DC arc and ICP torch: common features and differences

Supersonic plasma jets formed by DC arc and ICP torch: commo...

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IEEE International conference on Plasma Science (ICOPS)

作者： S.E. Selezneva v. Sember M. Rajabian D.v. Gravelle M.I. Boulos CRTP Chemical Engineering Department Université de Sherbrooke Quebec Canada

Summary form only given. Some new techniques using remote thermal plasma for plasma chemistry and plasma processing have been developed. These techniques include plasma spraying, PECvD of diamonds, diamond-like and polymer films. In remote plasma deposition, thermal plasma is formed by means of one of traditional plasma sources. The chamber pressure is reduced with the help of continuous pumping. In that way the flow is accelerated up to the supersonic speed. The plasma expansion is controlled using a specific torch nozzle design. For practical applications it is very important to find the parameters that determine the gas dynamical and physical properties of supersonic plasma flows. With this aim, we analyze the common features and the differences between supersonic jets of plasma formed by direct current arc and induction torch. The plasmas flowing from the DC and ICP torches with slightly sub-atmospheric pressures through the supersonic nozzles (with the outlet Mach numbers 1 and 1.5) into low-pressure (2kPa) chambers are compared. The analysis is performed by means of optical emission spectroscopy combined with the numerical modeling. In our simulations we incorporate user-defined subroutines for two-temperature model into commercially available FLUENT program. The results show that substantial interrelated deviations from thermal, ionization and Boltzmann equilibrium can be found in both jets. We demonstrate that the ratio of the static pressure at the chamber inlet to the chamber pressure together with the Mach number at the nozzle outlet and the rarefaction parameter define the supersonic jet structure, and not the chamber pressure alone. We show that the physical properties of supersonic plasmas depend on the way and place of plasma formation. Namely, it is important to distinguish the configurations where the plasma is firstly formed and then accelerated (as in ICP torch) and the configurations where the plasma is formed and accelerated at the same time (as

关键词： Plasma chemistry Plasma accelerators Plasma applications Plasma properties Plasma materials processing Plasma sources Acceleration Thermal spraying Polymer films Plasma simulation

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Integrated optical design

Integrated optical design

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conference on current developments in Lens design and optical engineering II

作者： Forney, P Lockheed Martin Space Syst Co Missiles & Space Operat Ctr Adv Technol Sunnyvale CA 94089 USA

ISBN: (纸本)0819441554

In order to produce an instrument or sensor design in the face of demanding environmental constraints of a spaceborne system, an integrated approach to sensor design has been developed that incorporates design tools for: optical design, mechanical design, structural, stray light and thermal analysis. This integrated approach can be extended to the entire payload design and its increased constraints.

关键词： optical design Computer aided design MATLAB Mirrors Sensors Mechanical engineering Systems modeling Thermal modeling Integrated modeling Integrated optics

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Infrared hybrid optics: analysis and implementation

Infrared hybrid optics: analysis and implementation

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conference on current developments in Lens design and optical engineering II

作者： Wood, AP THALES Opt Ltd St Asaph LL17 0LL Denbighshire Wales

ISBN: (纸本)0819441554

Hybrid optics offer a valuable aberration correction tool for the lens designer. However, careful consideration must be given to the calculation of the optical performance during the design process, and to the practical implementation of the elements if the potential benefits are to be realised in practice. optical performance can be accurately assessed by tracing multiple diffraction orders. It may be particularly important to utilise such a technique if, for example, the image-forming bundles sample a small number of diffractive zones. This situation is examined in detail.

关键词： optical design infrared diffractive optics

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Requirements for the design and production of high numerical aperture objectives for 4Pi confocal microscopy

Requirements for the design and production of high numerical...

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conference on current developments in Lens design and optical engineering II

作者： Sure, T Wesner, J Heil, J Leica Microsyst GmbH D-35578 Wetzlar Germany

ISBN: (纸本)0819441554

We discuss the requirements on design and production regarding geometric and chromatic aberrations for objectives used in 4Pi confocal microscopy. We show that even the selection of a category 1/1 glass will not automatically assure that these requirements are met. due to residual variations in the Abbe number nu within the manufacturers tolerances. Consequently, the optical design has to take into consideration the possibility of balancing chromatic aberrations by varying selected air spacings in the final assembly of each individual objective. We also demonstrate. that for analyzing the influence of aberrations on the intensity distribution along the optical axis. a scalar diffraction theory is still applicable and very useful.

关键词： 4Pi confocal microscopy geometrical aberrations chromatic aberrations diffraction limited objectives scalar diffraction theory apodization depolarization Twyman-Green interferometer

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Enhancements to the optimisation process in lens design (I)

Enhancements to the optimisation process in lens design (I)

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conference on current developments in Lens design and optical engineering II

作者： Schuhmann, R Adams, G The Optical Software Company United Kingdom LINOS Photonics GmbH Germany

ISBN: (纸本)0819441554

Over the years much time has been dedicated to improving lens optimisation routines. Most of the work has been upon the damped least squares (DLS) method. In this paper a number of theoretical and practical enhancements are presented. Some are new, others have already been published but never transposed into commercial software. These enhancements combine to allow the user to make more informed choices at every stage of an optimisation, and have now been incorporated into the widely used WinLens software package.

关键词： optical instrument lenses

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Linear wavelength spectrometer

Linear wavelength spectrometer

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conference on current developments in Lens design and optical engineering II

作者： Thibault, S INO Opt Engn Div St Foy PQ G1P 4S4 Canada

ISBN: (纸本)0819441554

Generally, a spectrometer uses a diffraction grating to spread the spectral components of a light incident on the diffraction grating on a one-dimensional detector. The detector is composed of pixels linearly distributed along a line. However, the diffracted light is not spread linearly on the detector which means that the Wavelength on pixel I is not linearly correlated with the wavelength on pixel 2. The resolution is therefore not constant for all the spectral range of the spectrometer. To know which pixel corresponds to which wavelength, a nonlinear calibration process must be applied to get a linear relation between the diffracted light position and the wavelength of this light. The new spectrometer that we present uses a special lens configuration name F-sin(theta) lens to provide a linear relation in the image plane between the pixel position and the wavelength of the light. The f-sin(theta) characteristic is defined as the difference in percent between the design position of the wavelength in the image plane and its ideal position, if the lens is perfect. The characteristic of the lens used in the spectrometer is better than 0.1%. The concept can also be used for WDM and DWDM applications.

关键词： spectrometer WDM DWDM distortion optical design guided optics

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optical designs for the Mars '03 rover cameras

Optical designs for the Mars '03 rover cameras

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conference on current developments in Lens design and optical engineering II

作者： Smith, GH Hagerott, EC Scherr, LM Herkenhoff, KE Bell, JF GHS Opt Pasadena CA 91101 USA

ISBN: (纸本)0819441554

In 2003, NASA is planning to send two robotic rover vehicles to explore the surface of Mars. The spacecraft will land on airbags in different, carefully chosen locations. The search for evidence indicating conditions favorable for past or present life will be a high priority. Each rover will carry a total of ten cameras of five various types. There will be a stereo pair of color panoramic cameras, a stereo pair of wide-field navigation cameras, one close-up camera on a movable arm, two stereo pairs of fisheye cameras for hazard avoidance, and one Sun sensor camera. This paper discusses the lenses for these cameras. Included are the specifications, design approaches, expected optical performances. prescriptions, and tolerances.

关键词： optical engineering lens design cameras Mars JPL

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F-sin(theta) lens system and applications

F-sin(theta) lens system and applications

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conference on current developments in Lens design and optical engineering II

作者： Thibault, S INO Opt Engn Div St Foy PQ G1P 4S4 Canada

ISBN: (纸本)0819441554

Introducing the desired amount of distortion in an optical system is possible and relatively straight forward for optical designer. Known f-theta lenses used in laser scanner system is one of the most popular lenses of this type. With the development of DWDM system, compact spectrometer and various grating based devices, the interest in solving optical problems with innovative optical design has been a revival. On the other hand, it is possible to simplify considerably the task of the software by designing more sophisticated optical element. The F-sin(theta) lens is such a device which can be used in various grating based devices to improve the performance. This optical device is intended to provide a new lens or lens group which can be used with a diffraction grating to provide a linear output plane with the wavelength (lambda), but also with the order of diffraction (m), or with the grating spatial frequency, or with the inverse of the index of refraction (l/n). Based on theoretical consideration, we calculated which amount of distortion is desired to get linear output plane for a grating based device. We present singlet. achromatic doublet and mirror having this characteristic. These F-sin(theta) lenses present satisfactory distortion charateristic and have an improved correction for the curvature of image plane. F-sin(theta) lens will be also name F-lambda lens.

关键词： WDM DWDM distortion optical design aberration grating spectrometer

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Advanced optical design for biochip scanning system

Advanced optical design for biochip scanning system

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conference on current developments in Lens design and optical engineering II

作者： Huang, GL Cheng, J Zhou, YX Feng, JH Liu, CX Jin, GF Wu, MX Yan, YB Yang, R Li, L Tsing Hua Univ Dept Biol Sci & Technol Beijing 100084 Peoples R China

ISBN: (纸本)0819441554

Laboratory-on-a-chip has been interested widely in recent years, where the sample preparation, bio-chemical reaction, separation, detection and analysis, are performed in a small biochip which is only a fingernall dimension. In order to obtain a high detection sensitivity I fluors/um(2) (one fluorescence molecule per square micrometer) in biochip scanning system it is required that the scanning objective lens is a big numerical aperture(>0.5), very small focal spot(<5um) and long back focal length(>3mm). In this paper, a combined lens is designed for the scanning objective lens, which is with big numerical aperture NA>0.7, very small focal spot(<2um) and long back focal length(>3mm). The phase aberrations of combined lens, including the aspherical aberration and the chromatic aberration corresponding to wavelength 532nm, 570nm 635nm, 670nm, are corrected very well. The encircled energy diagram of the lens is good to the diffraction limit. The focal spot diagram the optical path difference diagram, the transverse ray fan plot and the modulation transfer function, are studied also. A novel confocal scanning system of biochip with the designed combined lens as the objective lens is developed, some experiment results in a multi-channel biochip are obtained.

关键词： lens confocal fluorescence gene DNA biochip

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