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Conference on current developments in Lens design and optical engineering iii

作者： Gabay, C Berge, B Dovillaire, G Bucourt, S Ecole Normale Super Lyon F-69007 Lyon France

ISBN: (纸本)0819445347

We present real-time measurements of the wave front distortion induced by a variable focal lens. This lens, called Varioptic, is made of a transparent cell filled with twin liquids. We submit a 4.5mm in diameter lens upon a 110V voltage step inducing a optical power shift of about 25 dioptries (m(-1)). Characteristic response time is shown to be of the order of a few 1/100s, the lens recovering its full quality after 5/100s. We present a scaling analysis of this response time versus lens size.

关键词： Wavefronts Liquids Interfaces Wavefront distortions Spherical lenses CCD image sensors optical fibers Prototyping Solids Liquid crystals

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design of a dual field-of-view optical system for infra-red focal-plane arrays

Design of a dual field-of-view optical system for infra-red ...

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Conference on current developments in Lens design and optical engineering iii

作者： Akram, MN Royal Inst Technol Dept Microelect & Informat Technol SE-16440 Stockholm Sweden

ISBN: (纸本)0819445347

In this paper, the design of a dual field-of-view optical system for 3-5 mum infra-red focal-plane arrays is described. Preliminary calculations are done to determine the first-order parameters of the narrow and the wide-field modes. To achieve a switchable dual field-of-view system, two different optical configurations, one based on the axial motion of a lens group and the other based on a rotate-in motion of two separated lens groups, are studied and compared. Diffractive and conic surfaces are used to control the color and the monochromatic aberrations with less number of total lenses used. Paraxial and real-ray modelling of the Narcissus effect is described. It is shown that the rotate-in scheme achieves better optical performance in both the narrow and the wide-field modes. The axial-motion scheme suffers from poor lateral color in the wide-angle mode. The final optical designs along with their aberrations curves and MTF plots are presented showing excellent performance.

关键词： lens design infrared optics diffractive optics dual field-of-view focal-plane-arrays (FPA)

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design considerations for a compact infrared airborne imager to meet alignment and assembly requirements

Design considerations for a compact infrared airborne imager...

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Conference on current developments in Lens design and optical engineering iii

作者： Spencer, HM DRS Sensor Syst Torrance CA USA

ISBN: (纸本)0819445347

Helicopter mounted optical systems require compact packaging, good image performance (approaching the diffraction-limit), and must survive and operate in a rugged shock and thermal environment. The always-present requirement for low weight in an airborne sensor is paramount when considering the optical configuration. In addition, the usual list of optical requirements which must be satisfied within narrow tolerances, including field-of-view, vignetting, boresight, stray light rejection, and transmittance drive the optical design. It must be determined early in the engineering process which internal optical alignment adjustment provisions must be included, which may be included, and which will have to be omitted, since adding alignment features often conflicts with the requirement for optical component stability during operation and of course adds weight. When the system is to be modular and mates with another optical system, a telescope designed by different contractor in this case, additional alignment requirements between the two systems must be specified and agreed upon. Final delivered cost is certainly critical and "touch labor" assembly time must be determined and controlled. A clear plan for the alignment and assembly steps must be devised before the optical design can even begin to ensure that an arrangement of optical components amenable to adjustment is reached. The optical specification document should be written contemporaneously with the alignment plan to insure compatibility. The optics decisions that led to the success of this project are described and the final optical design is presented. A description of some unique pupil alignment adjustments, never performed by us in the infrared, is described.

关键词： Imaging systems Telescopes Sensors optical alignment Scanners Infrared radiation Objectives optical design Tolerancing Infrared imaging

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Novel CNC polishing process for control of form and texture on aspheric surfaces

Novel CNC polishing process for control of form and texture ...

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Conference on current developments in Lens design and optical engineering iii

作者： Walker, DD Beaucamp, ATH Brooks, D Freeman, R King, A McCavana, G Morten, R Riley, D Simms, J UCL Dept Phys & Astron Opt Sci Lab London WC1E 6BT England

ISBN: (纸本)0819445347

We first consider the potential impact of a technology that could deliver polished, accurate aspheric surfaces in a routine and automated manner. We then summarise the technical challenge, and present an appraisal of the performance of the novel 'Precessions' process, which is a major advance in this direction. We outline the design concepts behind the productionized CNC polishing machines which executes the process, and then describe the progress developing strategies to preserve form when polishing ground surfaces, and to correct form on both pre-ground and polished surfaces. Particular consideration is given to resolving the inherent difficulties of control of centres on rotationally-symmetric parts. We then report on experimental results achieved with the machines. Finally, we present our programme to extend the control-algorithms to handle fully free-form surfaces, and draw conclusions about the effectiveness and generality of the 'Precessions' technique.

关键词： Polishing Surface finishing Aspheric lenses Process control Raster graphics Spherical lenses Mirrors Astronomy optical instrument design Polishing equipment

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The aerodynamic installation of optical fibres in telecommunication networks

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL engineering 2002年第E4期216卷 193-205页

作者： McNeil, DA Addlesee, AJ Taylor, J Heriot Watt Univ Dept Mech & Chem Engn Edinburgh EH14 4AS Midlothian Scotland

The installation of optical fibres for communication purposes is increasingly being carried out using a blowing technique. This study reviews the basis of the current design methods for this technique and proposes a new method based on a more traditional fluid mechanics approach. The method is used to demonstrate how far optical fibres can be blown and the stress levels likely to be encountered by them at various positions within their journey. The method will allow for future technological developments to be simulated by allowing for air drag on the fibre and the constraining tube wall to be treated differently.

关键词： single-phase flow blowing lengths fibre installation

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Reflectivity of the Al-Cr stray-light-absorptive coating

Reflectivity of the Al-Cr stray-light-absorptive coating

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Conference on current developments in Lens design and optical engineering iii

作者： Anisimov, VP Anisimova, IA Moldosanov, KA Skrynnikov, AM Kashirin, VA Kyrgyz Acad Sci Inst Chem & Chem Technol Bishkek 720071 Kyrgyzstan

ISBN: (纸本)0819445347

Results of measurements of the total hemispherical reflectance (THR), emissivity c and solar radiation absorption factor alpha(s) of the Al-Cr stray-light-absorptive coating are reported. This coating was designed to reduce the stray sunlight background in aerospace instruments. Generally, this problem arises when a density of instruments installed on the satellite is high and it is difficult to avoid getting to instrument the light reflected by neighboring devices. The THR, epsilon and alpha(s) measurement results are presented for 10 wavelengths within a range from. 400 to 927 nm, and also at 121.6 nm, the most intensive line of the solar UV spectrum, which is able to create considerable contribution to the detector noise in space devices. The goal of present experiments was to test an idea that by providing the electron scattering in the coating skin layer, it is possible to reduce the THR. To have the samples with increased electron scattering intensity, the samples of the Al-Cr coating were manufactured. As in the Al-Cr alloy the d-band of chromium electrons is located in the vicinity of the Fermi energy of Al, in this alloy a considerable electron scattering takes place. Therefore, within the skin layer of such coating, the electrons excited by photons transfer their energies and momenta to the lattice and other electrons instead of releasing the secondary photons. Hence, the reflectivity of the Al-Cr coating might be reduced. The prepared samples and performed experiments confirmed this assumption. According to the measurement results, the chromium appears to be an acceptable additional admixture to provide a further reflectivity reduction in the previously studied promising Al-N coating.

关键词： stray light optical engineering stray-light-absorptive coating low reflectivity material

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Sphere-shaped durable and isometric diamond powders for super-quality treatment of optical materials

Sphere-shaped durable and isometric diamond powders for supe...

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Conference on current developments in Lens design and optical engineering iii

作者： Samoylova, L Krinskaya, E R&P Co LTD Alkion Kiev Ukraine

ISBN: (纸本)0819445347

For the first time, developed are sphere-shaped precision diamond micropowders ASMV-RM having a number of unique properties - advanced, ordered crystal structure, improved surface morphology, maximal hardening of crystals with increase wear-resistant, with high uniformity of grains and in physico-mechanical properties, with absence of needle, sharp-angled crystals. These exclusive properties enable to provide the considerable increase of productivity of processes at essential improvement of surface quality during thin grinding and polishing of products by these micropowders. They are outside of a competition to the standard marks of diamonds of general purpose as were created for new highly perspective areas of applications focused on high technologies in electronics, optics and other branches of modem engineering. In precision micropowders ASMV-RM enormous potential of diamonds is realized. The technology of precision diamond micropowders preparation is based on results of the scientific school by Academician of the National Academy of Sciences of Ukraine V.I. Trefilov and complex approach directed on deepened influence on a material with application of modem effective technologies and the optimum technical solutions. The technology of their manufacture is referred to high technologies, and precision micropowders have created a new direction in diamond branch. Real conditions for realization of technical revolution in creation and use of a new class precision diamond micropowders are now created.

关键词： dislocation precision sphere-shaped micropowder physico-mechanical properties static diamonds dynamic diamonds

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developments on the UK FMOS project for the Subaru telescope

Developments on the UK FMOS project for the Subaru telescope

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Instrument design and Performance for optical/Infrared Ground-based Telescopes

作者： Lewis, Ian J. Dalton, Gavin B. Holmes, Alan Brooks, Barney Band, Cyril Tosh, Ian Woodhouse, Guy Cavan, Nick Murray, Graham Robertson, David Dipper, Nigel Luke, Peter Astrophysics University of Oxford Keble Road Oxford OX1 3RH United Kingdom Rutherford Appleton Laboratory Didcot Oxfordshire OX11 0QX United Kingdom Department of Physics University of Durham South Road Durham DH1 3LE United Kingdom

We describe the UK participation in the FMOS project to provide multi-object IR spectroscopy for the Subaru telescope. The UK is working on the design of an OH suppression IR spectrograph, this work comprises the optical design, the opto-mechanical layout, spectrograph thermal environment and cryogenics and detector control system. We give a progress report on the current design work.

关键词： Telescopes

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design decisions for data management with the LSST

Design decisions for data management with the LSST

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3rd Conference on Observatory Operations to Optimize Scientific Return

作者： Connolly, A Boroson, T Univ. of Pittsburgh (United States) National Optical Astronomy Observatory (United States)

ISBN: (纸本)0819446238

In the coming decade we will build on the foundations of current large scale imaging surveys such as the SDSS, 2MASS and MACHO to develop deep, wide-field imaging surveys covering over 15,000 square degrees that are designed to probe to the time domain. One such project is the Large Synoptic Survey Telescope (LSST). We describe here some of the data management challenges we face in moving from the current generation of surveys to an imaging program of the size of the LSST. Scaling from todays deep CCD imaging surveys and wide-field photometric surveys we show that the computational challenge of analyzing the data from a three Gigapixel camera with 10s integrations should be manageable on the time frame that the LSST is expected to be delivered. While encouraging, these hardware considerations are only a very small aspect of the software engineering and data management procedures that must be developed in order for the LSST to succeed.

关键词： data management software engineering LSST survey telescopes wide-field imaging

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Infrared camera and spectrograph for the Subaru Telescope: Performance improvement with the new Aladdin-iii array

Infrared camera and spectrograph for the Subaru Telescope: P...

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Instrument design for optical/Infrared Ground-based Telescopes

作者： Terada, Hiroshi Kobayashi, Naoto Tokunaga, Alan Pyo, Tae Soo Goto, Miwa Weber, Mark Potter, Robert Onaka, Peter Subaru Telescope Natl. Astron. Observatory of Japan 650 North A'ohoku Place Hilo HI 96720 United States Institute for Astronomy University of Hawaii 2680 Woodlawn Drive Honolulu HI 96822 United States

We report on the significantly improved performance of the Infrared Camera and Spectrograph (IRCS) for the Subaru Telescope. The IRCS consists of the camera side for imaging and grism spectroscopy and the spectrograph side for echelle spectroscopy. Due to the low sensitivity of the previous Aladdin-II engineering grade InSb infrared array on the camera side, the capability of imaging and grism spectroscopy was reduced. Thus, we replaced the array on the camera side into the new Aladdin-iii array in August 2001. The newly installed Aladdin-iii array has 1.9 times higher quantum efficiency (95%), 2/3 lower read-out noise (12e- with 16 non-destructive-readout at 27.5 K of the array temperature) and better cosmetics than the old Aladdin-II array. We have also obtained grism spectra for a comparison of performances with the old and the new arrays. The spectra with the new array show about twice better signal-to-noise for each spectral element and almost no systematic noise. currently we have two different types of arrays: Aladdin-II array on the spectrograph side and the science grade Aladdin-iii array on the camera side. We will also present dark current, read-out noise, linearity curve and the other characteristics as a function of array temperatures to summarize the current performance of both arrays. We plan to upgrade the Aladdin-II array on the spectrograph side to a new Aladdin-iii array in summer 2003.

关键词： Infrared imaging

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