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

作者： Sarlot, RJ Bresloff, CJ Burge, JH Fitz-Patrick, BC McGuire, PC Stamper, BL Zhao, CY Univ Arizona Steward Observ Tucson AZ 85721 USA

ISBN: (纸本)0819432652

Steward Observatory is completing the manufacture of a deformable f/15 secondary mirror for the 6.5m Multiple Mirror Telescope conversion that will, along with the wavefront sensing system, compensate for atmospheric turbulence. A potential difficulty of an adaptive secondary mirror is the ability to verify the commanded mirror shapes of a large convex deformable surface. An optical design is presently being implemented to test the deformable mirror's closed loop control system by optically projecting an artificial star to simulate starlight in the actual telescope. The test system has been designed to verify the control system by fitting into both a laboratory test structure as well as the telescope support structure itself. The optical design relies on two wavelength computer generated holograms used to remove spherical aberration as well as aid in the alignment of the test system optics by projecting alignment patterns.

关键词： adaptive secondary aspheric testing Multiple Mirror Telescope Shimmulator

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optical design of a visible and infrared survey telescope for astronomy

Optical design of a visible and infrared survey telescope fo...

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

作者： Atad-Ettedgui, E Casali, M Hawarden, TG Henry, DM Worswick, SP Royal Observ UK Astron Technol Ctr Edinburgh EH9 3HJ Midlothian Scotland

ISBN: (纸本)0819432652

A number of preliminary optical designs for a new generation of 4 metre astronomical survey telescopes have been investigated. These have large fields of view and operate in both the visible and near IR astronomical wavebands. Typical requirements for dual band systems of this type are presented. Two designs for prime focus refractive field corrector systems are presented, with and without aspheric surfaces. The use of aspheric surfaces on the field corrector lenses is shown to allow a large field of view (2 degrees diameter) to be achieved. A design for a three mirror reflective system is presented which also allows a 2 degrees field to be achieved. An infrared imager, based on a modified Schmidt camera, is presented which allows a 1 degrees field of view to be achieved. Additionally, a modified Ritchey-Chretien telescope, incorporating refracting field corrector lenses is presented. This design provides a large field of view over both the visible and lR wavebands. The mechanical constraints of combining these systems into dual channel systems are also discussed.

关键词： wide field astronomy survey telescope optical designs visible and infrared

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Phase change induced in laser diode interferometric system for measurements with optical fiber in composite material

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Proceedings of SPIE - The International Society for optical engineering 1999年 3626卷 40-47页

作者： Souto, J.A.G. Lamela, H. Universidad Carlos III de Madrid Madrid Spain

In this paper we present results of our interferometric system for embedded optical fiber in composite material, where a laser diode is used as light source. optical phase changes induced by laser diode injection current modulation are characterized in order to apply an optoelectronic setup for stabilization and optical phase modulation. He-Ne source versus laser diode are compared for the system. Details on parameter characterization, specially visibility drift and environmental disturbance impact, are analyzed. Experimental design and the results observed are also given.

关键词： Semiconductor lasers

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Hyperbolic and oval cylindrical lenses to compress the semiconductor laser beam

Hyperbolic and oval cylindrical lenses to compress the semic...

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Proceedings of the 1999 current developments in optical design and optical engineering Viii

作者： Li, ChunXia Li, RunShun Liu, LiHeng Harbin Inst of Technology Harbin China

To utilize the mother lines to be perpendicular to each other in front and rear groups of cylindrical lenses, diffusing beam 44°×3° from the window of semiconductor laser are compressed as `parallel rays' to emerge into ±0.0025 rad. The sizes of the laser window are 0.1285 mm×3.239 mm. The front focal points of cylindrical lenses in two groups are superimposed on the center of the window, and its types of second surfaces are hyperbolic and oval.

关键词： optical instrument lenses

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Effects and prediction of stray light produced by diffractive lenses

Effects and prediction of stray light produced by diffractiv...

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

作者： Thibault, S Renaud, N Wang, M INO Opt Engn Grp St Foy PQ G1P 4N8 Canada

ISBN: (纸本)0819432652

Correlation between computational models and corresponding experimental data of stray light produced by unwanted diffraction orders of diffractive lenses is described. It is shown that the attractive scaler model under Fresnel approximation does not agree with experimental data. The validity of Fresnel approximation for multi-order focusing optics is derived to explain the limitation of the scaler approach. Geometrical models with both coherent and incoherent summation of each diffractive orders coupled with efficiency estimation is used with success. The model takes into account the local diffraction efficiency and also of the number of diffractive orders supported locally by the structure. This geometrical optics model can be used in standard optical design software. Therefore it may be recommended as an additional tool for stray light analysis at the design stage of hybrid refractive/diffractive optical systems. In a second part, the impact of unwanted diffraction orders when diffractive optics is used in visible imaging systems is discussed. Several experimental observations about the use of plastic refractive/diffractive lens in relation to different fabrication process used to build the lens are also discussed. From those observations, we recommend an approach to reduce the stray light produced by the diffractive lens. In conclusion, a serious stray light analysis is mandatory in the design of visible imaging systems using diffractive lenses.

关键词： stray light diffractive optical element imaging optical design

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Modeling tools for integrated and fiber optical devices

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Proceedings of SPIE - The International Society for optical engineering 1999年 3620卷 162-173页

作者： Tzolov, Velko P. Feng, Dazeng Tanev, Stoyan Jakubczyk, Z.Jan Optiwave Corp Nepean Canada

This presentation will emphasize the current status of advanced design and simulation tools in photonics technology. The focus will be on Wavelength Division Multiplexing (WDM) component and integrated optic circuits modeling, although some aspects of optical link simulations will also be discussed. A wide variety of numerical methods such as the Beam Propagation Method (BPM), the Coupled Mode Theory (CMT), the Transfer Matrix Method (TMM), and the Finite-Difference Time Domain Method (FDTDM) in their state-of-the-art implementation will be presented. The results from simulating selected photonic components will be discussed.

关键词： Integrated optoelectronics

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Full field mapping and analysis of veiling glare sources for Helmet Mounted Display systems

Full field mapping and analysis of veiling glare sources for...

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

作者： Hasenauer, DM Kunick, JM Opt Res Associates Pasadena CA 91107 USA

ISBN: (纸本)0819432652

The performance of an optical system can be degraded by the intrusion of stray light from sources both inside and outside of the system field of view. Stray light, or "veiling glare," can be particularly distracting in visual systems such as Helmet Mounted Display (HMD) systems. This paper describes techniques used by the authors to map stray light source positions in the far field for HMD systems and to quantitatively define their impact. The mapping can be performed over 4 pi steradians (i.e., over a full sphere) both inside and outside the system field of view. Monte-Carlo ray tracing algorithms are utilized for determining an effective source intensity distribution across the entire far field and a subtractive technique is utilized that separates the veiling glare component from the desired optical signal component. Once the major veiling glare source positions are identified, methods to reduce veiling glare can be determined. A technique for reducing noise in the calculation due to the statistical nature of the Monte Carlo ray trace is also discussed.

关键词： optical design illumination stray radiation stray light veiling glare LightTools (R)

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Segmented illumination lenses for steplighting and wall-washing

Segmented illumination lenses for steplighting and wall-wash...

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

作者： Parkyn, WA Teledyne Lighting and Display Products Inc. (United States)

ISBN: (纸本)0819432652

Many illumination situations involve a flat surface and an oblique luminaire placement. Today's commercially available luminaires give very uneven illumination here. A novel injection-moldable segmented lens is presented that will uniformly illuminate a rectangular zone, such as a stair-step or a picture on a wall. Its design is a development of prior methods(1) of lens-surface generation that derived the array of surface normal vectors required to match a source with a particular illumination prescription. This matching is done via grids on the unit sphere: one for the source and one for the prescription. The cells of these two grids are sized so that they have the same flux of lumens, according to the source intensity and the prescribed illumination, respectively. The first development is the use of an equi-flux polar grid for the target rectangle, because most light sources have circular symmetry. The second development is the radial segmentation of the lens surface in order to approximate the non-irrotational array of surface normal vectors derived from the two grids. designs are presented for step-lighting by LEDs and fiber-optic billboard lighting.

关键词： Light emitting diodes Lenses Light sources and illumination optical spheres Lens design Fiber optics Optics manufacturing Reflectors Light sources Refractive index

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design verifications of a linear laser encoder with high head-to-scale tolerance

Design verifications of a linear laser encoder with high hea...

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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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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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