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8th conference on current developments in optical design and optical engineering

作者： Wu, CC Chen, YC Lee, CK Hsieh, CT Wu, WJ Lu, SS Natl Taiwan Univ Inst Engn Mech Taipei 10764 Taiwan

ISBN: (纸本)0819432652

Laser encoders overcome the fundamental resolution limit of geometrical optical encoders by cleverly converting the diffraction limit to phase coded information so as to facilitate nanometer displacement measurement. As positioning information was coded within the optical wavefront of laser encoders, interferometry principle thus must be adopted within the design of the laser encoders. This effect has posed a very strong alignment tolerance among various components of the whole laser encoder, which in turn impose a serious user adaptation bottleneck. Out of all alignment tolerance, the head-to-scale alignment tolerance represents the most important hindrance for wider applications. Improving the IBM laser optical encoder design by taking into the consideration of manufacturing tolerance of various optical components, an innovative linear laser encoder with very high head-to-scale tolerance is presented in this article. Efficiency of the TE/TM incident Light beams on the grating scale used are examined theoretically and verified experimentally so as to provide design optimizations of the grating scale. Effect of various grating scales, quartz master or polymer-based grating replicate, is also detailed. Signal processing used to decode the quadrature based positioning optical signal is also studied. Experimental results that verify the resolutions of the tabletop laser encoder prototype by comparing the decoded quadrature signal and a HP laser interferometer output signal is also presented.

关键词： laser encoder alignment tolerance alignment tooling diffractive grating diffractive encoder

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High power 0.98 μm broad waveguide lasers using novel material system of InGaAs/InGaAsP/AlGaAs

High power 0.98 μm broad waveguide lasers using novel mater...

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8th conference on current developments in optical design and optical engineering

作者： Yang, GW Hwu, RJ Chern, JH Xu, ZT Xu, JY Univ Utah Dept Elect Engn Salt Lake City UT 84112 USA

ISBN: (纸本)0819432652

We describe the theoretical design and experimental fabrication of high power 0.98 mu m strained quantum well lasers employing broad waveguide structure and novel hybrid material system of Al-free InGaAs/InGaAsP active region and AlGaAs cladding layers. The use of AlGaAs cladding, instead of InGaP, provides advantages in flexibility of laser structure design, simple epitaxial growth, improvement of surface morphology and laser performance. In addition to the theoretical study of the new structure, we successfully demonstrate the design by obtaining high performance laser devices. The as-grown InGaAs/InGaAsP/AlGaAs laser material exhibits very high quality with low threshold current density of 200 A/cm(2) (at a cavity length of 800 mu m), high internal quantum efficiency of similar to 93%, and low internal loss of 1.2 cm(-1). For 100 Gun-wide stripe lasers with cavity length of 800 mu m, a high slope efficiency of 1.03 W/A, low vertical beam divergence of 36 degrees, high output power of 3.65 W, and very high characteristic temperature coefficient (T-0) of 250 K are achieved.

关键词： semiconductor lasers optical structure design semiconductor epitaxial layers quantum well lasers semiconductor materials thin films

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Agile beam director system design (ROBS/TCATS optical tracker)

Agile beam director system design (ROBS/TCATS optical tracke...

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8th conference on current developments in optical design and optical engineering

作者： Neff, BW Trissel, RG Dunn, M Scotese, L Thermotrex Corp San Diego CA 92121 USA

ISBN: (纸本)0819432652

The ROBS (Rapid optical Beam Steering) tracking telescope was invented and developed at TTC to provide a high acceleration, large aperture beam steering system for rapid pointing to multiple objects. The optical system consists of a fast, oversized spherical primary mirror with the 50 cm aperture stop at the center of curvature of the primary mirror (CCP). A lightweight secondary mirror selects the instantaneous field of view by scanning over the petzval image surface of the primary mirror. The secondary mirror is gimbaled about the CCP on a rigid, lightweight mast. The system's symmetry about the CCP simplifies the optical and mechanical design and provides very rapid retargeting over a 30 degree field of regard for multiple target tracking. Field corrector and pupil relay optics inside the support tube collimate the light through coude' optics to passive sensors and laser radar optics. The 2-sphere, 2-asphere aplanatic, anastigmant all-reflective design corrects the 9.1 mr of spherical aberration from the F/1 primary and provides 10 microradian resolution over a 5 mr field of view. The system incorporates near field focus adjustment to provide high resolution imaging and laser ranging over a large volume of space. Two 50 cm systems have been built and demonstrated tracking multiple targets in the field. This paper describes the opto-mechanical design and demonstrated system capabilities.

关键词： telescope with spherical primary beam steering laser radar system optical tracker

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design of a day/night star camera system

Design of a day/night star camera system

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8th conference on current developments in optical design and optical engineering

作者： Alexander, CD Swift, W Ghosh, K Ramsey, B NASA George C Marshall Space Flight Ctr Dept Space Sci Huntsville AL 35812 USA

ISBN: (纸本)0819432652

This paper describes the design of a camera system capable of acquiring stars during both the day and night cycles of a high altitude balloon flight (35-42 km). The camera system will be filtered to operate in the R and I bands (similar to 600-1000nm), and simulations have been run using MODTRAN atmospheric code to determine the worse case sky brightness at 35km. With a worse case daytime sky brightness of 2x10(-5) W/cm(2)/sr/mu m at 600nm, the sensitivity of the camera system will allow acquisition of at least 1-2 stars/degrees(2) at star magnitude limits of 7.8-8.1. The system will have an F2.8, 64.3mm diameter lens and a 1340 x 1037 CCD digitized to 12 bits. The CCD is comprised of 6.8 mu m x 6.8 mu m pixels with a well depth of 45,000 electrons and quantum efficiency of 0.54 at 700nm. The camera's field-of-view will be 6.33 degrees(2) and provide attitude knowledge to 8 arcsec or better. A test flight of the system is scheduled for fall 1999.

关键词： star camera aspect system stratospheric balloon flights daytime star camera R band

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optical design of ARIES: the new near infrared science instrument for the adaptive f/15 Multiple Mirror Telescope

Optical design of ARIES: the new near infrared science instr...

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8th conference on current developments in optical design and optical engineering

作者： Sarlot, RJ McCarthy, DW Burge, JH Ge, J Univ Arizona Steward Observ Tucson AZ 85721 USA

ISBN: (纸本)0819432652

Steward Observatory is building a deformable f/15 secondary mirror that will compensate for atmospheric turbulence for the 6.5 m Multiple Mirror Telescope conversion. With the proposed adaptive optics system, this new telescope is expected to resolve diffraction limited images (greater than 80% Strehl ratio at 2.2 mu m), approximately an order of magnitude better than present seeing. This improved visibility with a larger fight collecting area and low thermal background requires a new science instrument, diffraction limited for the 1 to 5 mu m region. This science instrument, presently in its early manufacturing stages, consists of four cameras (optimized for plate scales from 0.019 arcsec/pixel to 0.102 arcsec/pixel), low resolution spectroscopy with grisms (lambda/Delta lambda from 250 to 500), high resolution spectroscopy with a cross-dispersed Echelle grating (lambda/Delta lambda from 3,000 to 60,000) and an atmospheric dispersion corrector. The cameras will provide simultaneous slit viewing, differential imaging and two pixel sampling over the full wavelength band. Each camera will operate with a 1024x1024 HgCdTe array optimized for the spectral region of the camera. An infrared tip/tilt sensor is also incorporated into the instrument that will relay natural guide star motion to the adaptive secondary in a closed-loop approach. This paper is an optical design instrument overview.

关键词： adaptive optics infrared camera spectrograph atmospheric dispersion corrector MMT

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optical microscope for nuclear emulsion readout -: system design and results in application

Optical microscope for nuclear emulsion readout -: system de...

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8th conference on current developments in optical design and optical engineering

作者： Winkler, K Körner, L Gussek, P Balogh, I Breitfelder, S Schlichting, J Dupraz, JP Fabre, JP Panman, J Papadopoulos, IM Zucchelli, P van de vyver, B Syst GmbH Opt JENOPTIK Laser Jena Germany

ISBN: (纸本)0819432652

Experiments such as CHORUS at CERN require the inspection of a large amount of nuclear emulsion plates exposed to particle beams. Rare events need to be found, measured and analysed. Their features are stored as grains in microscopic dimensions in a three-dimensional stack of plates. A new, fully automatic immersion microscope system was developed for this purpose. It features high resolution, small depth of focus, large working distance, large field of view and synchronization of illumination and detector. An additional requirement is given by variations in the refraction index and in the relative thickness of immersion oil and emulsion. The approach used here is an imaging system based on a vario objective lens (variable oil immersion) with extreme numerical aperture, large working distance and wide field, combined with a matched high-aperture Koehler illuminator. The light source is a mercury are lamp, combined with a filter package for the g-line. It includes liquid crystal elements for synchronized shuttering and variable attenuation. The theoretical resolution is less than 1 micron in x, y, z within a volume of 0.5mm diameter (x, y) times 1 mm scanning depth (z) in all situations within a predefined index range (1.49 to 1.54). Three identical pieces of the system have been built. The experimentally measured resolution confirms the expectations and is better than 1 micron in all three dimensions. This is the result of a complex process of system design and manufacturing, unifying optical, opto-mechanical and optoelectronical contributions. This process spans from the early stages of feasibility and manufacturing up to the test and adjustment procedures. The three prototypes are operational since the fall of 1998 in the frame of the CHORUS project. Practical experience and application results are presented.

关键词： optical microscopy oil immersion nuclear emulsion readout variable immersion systems design

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Recent developments in hybrid mirror technology for the Next Generation Space Telescope

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Proceedings of SPIE - The International Society for optical engineering 1999年 3749卷 82-83页

作者： Dodson, Kelly J. Mehle, Greg v. Kasl, Eldon P. Composite Optics Inc San Diego United States

The objective of this paper is to report the recent developments in lightweight mirror technology at Composite Optics, Incorporated (COI). The developments are a result of the activities being conducted in support of the Next Generation Space Telescope (NGST) Program. The sponsors of these efforts are the NASA Marshall and Goddard Space Flight Centers. The requirements, design approach, performance, and the technology status for the program are summarized. The emergence of composite materials provides exciting potential for nontraditional, accurate, lightweight, stable, stiff, and high strength mirrors. This evolving technology promises significant improvement in reducing weight, cost and cycle time for future infrared, visible, and x-ray systems. Customers currently embracing composite mirror technology for radiometric use are already reaping substantial system performance benefits. Other customers interested in LIDAR, IR, visible, and grazing incidence x-ray applications are eagerly awaiting successful completion of current technology development and demonstration efforts.

关键词： Mirrors

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Revisions to the JDL data fusion model

Revisions to the JDL data fusion model

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conference on Sensor Fusion - Architectures, Algorithms, and Applications III

作者： Steinberg, AN Bowman, CL White, FE ERIM Int Inc Arlington VA 22209 USA

ISBN: (纸本)0819431931

The Data Fusion Model maintained by the Joint Directors of Laboratories (JDL) Data Fusion Group is the most widely-used method for categorizing data fusion-related functions. This paper discusses the current effort to revise and expand this model to facilitate the cost-effective development, acquisition, integration and operation of multi-sensor/multi-source systems. Data fusion involves combining information - in the broadest sense - to estimate or predict the state of some aspect of the universe. These may be represented in terms of attributive and relational states. If the job is to estimate the state of a people (or any other sentient beings), it can be useful to include consideration of informational and perceptual stares in addition to the physical state. Developing cost-effective multi-source information systems requires a method for specifying data fusion processing and control functions, interfaces, and associated databases. The lack of common engineering standards for data fusion systems has been a major impediment to integration and re-use of available technology: current developments do nor lend themselves to objective evaluation, comparison or re-use. This paper reports on proposed revisions and expansions of the JDL Data Fusion model to remedy some of these deficiencies. This involves broadening the functional model and related taxonomy beyond the original military focus, and integrating the Data Fusion Tree Architecture model for system description, design and development.

关键词： Data fusion Data modeling Systems modeling Standards development Data processing Sensors Algorithm development Data analysis Systems engineering Signal detection

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Recent developments in hybrid mirror technology for the Next Generation Space Telescope

Recent developments in hybrid mirror technology for the Next...

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Proceedings of the 1999 18th Congress of the International Commission for Optics (ICO XvIII): Optics for the Next Millennium

作者： Dodson, Kelly J. Mehle, Greg v. Kasl, Eldon P. Composite Optics Inc San Diego CA United States

关键词： Mirrors

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Shallow water expendable and trawler safe environmental profilers

Shallow water expendable and trawler safe environmental prof...

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MTS/IEEE conference on Riding the Crest Into the 21st Century (OCEANS 99)

作者： Tyce, R de Strobel, F Grandi, v Gualdesi, L Univ Rhode Isl Dept Ocean Engn Narragansett RI 02882 USA

ISBN: (纸本)0933957246

A prototype Shallow Water Expendable Environmental Profiler (SWEEP) for rapid environment assessment has been developed and tested by SACLANT Undersea Research Centre in collaboration with the University of Rhode Island Department of Ocean engineering. The SWEEP system is intended for autonomous vertical profiling of acoustic, optical and physical properties of the water column and seafloor in depths down to 100m. It is designed for data return and control via cellular phone or worldwide satellite packet communication while on the surface. The first prototype is an anchored profiler that uses an integral buoyant winch and sensor package to profile from the bottom up to the surface. The system is modular in design, allowing modules to be reused in new deployment alternatives. Already being planned is a Shallow water Environmental Profiler, in Trawl safe, Realtime configuration (SEPTR). SEPTR is a bottom-up profiler with added ADCP, tide/wave gage and extended duration battery packages in a recoverable trawler safe housing. The design duration for the SWEEP is one month or 100 profiles in 100m water depth. The design duration for SEPTR is 3 months or 360 profiles in 100m. The profilers make use of new low cost, high performance sensors that include the following: 3-axis acceleration and magnetic field sensors Conductivity, temperature and pressure sensors Ambient light / optical attenuation sensors Ambient noise and current sensors Seafloor acoustic sensors DGPS navigation sensors Two way communication of data, position and control allows profile results to be returned in real time, and operational commands, profile schedules, and DGPS correctors to be sent to multiple profiler instruments. Complete profiles will also be stored on board for recoverable units.

关键词： Oceanography

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