We present a purely mechanical means of producing highly concentric spherical lenses at the endfaces of optical fibers. The production process has two stages. First, conical lenses are produced in a grinding process t...
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We present a purely mechanical means of producing highly concentric spherical lenses at the endfaces of optical fibers. The production process has two stages. First, conical lenses are produced in a grinding process that ensures excellent concentricity. Then, the conical lenses are transformed to spherical lenses using a novel process called loose abrasive blasting. The cone grinding is carried out on a microgrinding machine, which has a sophisticated control system that enables the production of precision conical lenses. The blasting is carried out on a diamond blasting machine. Plots showing automatic centering performance of the microgrinding machine and scanning electron microscopy images of the conical and spherical lenses are presented. (c) 2005 Society of Photo-optical Instrumentation Engineers.
A baseline design for NASA's Terrestrial Planet Finder Coronagraph (TPFC) starlight suppression system (SSS) is described. The design is based on a 8×3.5m elliptical aperture telescope leading to terrestrial ...
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A baseline design for NASA's Terrestrial Planet Finder Coronagraph (TPFC) starlight suppression system (SSS) is described. The design is based on a 8×3.5m elliptical aperture telescope leading to terrestrial planet detection at a minimum angle of ∼4λ/D. The design accommodates classical Lyot coronagraph as well as shaped pupil approaches and includes separate optical paths for two polarizations each with its own deformable mirror control. Critical design challenges and trades are described.
The Terrestrial Planet Finder-Coronagraph (TPF-C) is a NASA exploration mission to directly detect and characterize terrestrial exoplanets at visible wavelengths. The TPF-C observatory must be able to distinguish a pl...
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The Terrestrial Planet Finder-Coronagraph (TPF-C) is a NASA exploration mission to directly detect and characterize terrestrial exoplanets at visible wavelengths. The TPF-C observatory must be able to distinguish a planet that is more than 10 orders of magnitude fainter than its parent star at a separation of 75 milli-arc-seconds (mas). Coronagraphic detection requires a large aperture telescope to resolve the exoplanet from its star, and extreme stability during detection and characterization observations. This paper discusses the requirements and trade studies leading to the current baseline opticaldesign for the TPF-C telescope. The current baseline design is summarized and its prescription is presented.
Rayleigh scaling equations for resolution and the control of computer chip critical dimensions (CD) within a finite depth of focus (DOF) have always indicated that resolution is better improved by reductions in wavele...
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Rayleigh scaling equations for resolution and the control of computer chip critical dimensions (CD) within a finite depth of focus (DOF) have always indicated that resolution is better improved by reductions in wavelength of exposure light rather than by increasing the numerical aperture (NA) of the projection optics, particularly as it approaches the physical limit in air of 1.0. However, liquid immersion of the image increases the physical NA limits and presents new opticaldesign challenges, while postponing the necessity for drastic reductions in the wavelength.
We present a purely mechanical means of producing highly concentric spherical lenses at the endfaces of optical fibers. The production process has two stages. First, conical lenses are produced in a grinding process t...
详细信息
ISBN:
(纸本)0819454613
We present a purely mechanical means of producing highly concentric spherical lenses at the endfaces of optical fibers. The production process has two stages. First, conical lenses are produced in a grinding process that ensures excellent concentricity. Then, the conical lenses are transformed to spherical lenses using a novel process called loose abrasive blasting. The cone grinding is carried out on a microgrinding machine, which has a sophisticated control system that enables the production of precision conical lenses. The blasting is carried out on a diamond blasting machine. Plots showing automatic centering performance of the microgrinding machine and scanning electron microscopy images of the conical and spherical lenses are presented. (c) 2005 Society of Photo-optical Instrumentation Engineers.
We report on our work on producing liquid crystal switchable modal lenses and their use in a compound lens system in order to produce variable focus/zoom lenses. We describe work on producing a high power lens, and pr...
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We report on our work on producing liquid crystal switchable modal lenses and their use in a compound lens system in order to produce variable focus/zoom lenses. We describe work on producing a high power lens, and present theoretical work on off-axis phase modulation in a liquid crystal lens which is important in order to be able to carry out a complete opticaldesign of a liquid crystal lens.
In this paper I will describe some of the properties that govern retarders made of uni-axial birefrigent materials, and discuss how to optimize wide field of view superachromatic retarders using commercially available...
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In this paper I will describe some of the properties that govern retarders made of uni-axial birefrigent materials, and discuss how to optimize wide field of view superachromatic retarders using commercially available software. To demonstrate the technique, examples of half wave plates are shown, that achieve maximum 0.04 waves of retardance deviation over the wavelength range 300 nm to 1100 nm having a field of view +/-10 degrees.
Several small-field catadioptric opticaldesigns have been developed over the last decade to meet the demanding needs from lithographers. design solutions that use a multi-function component can provide nearly perfect...
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Several small-field catadioptric opticaldesigns have been developed over the last decade to meet the demanding needs from lithographers. design solutions that use a multi-function component can provide nearly perfect wavefront correction for optical systems with broad bandwidth sources, such as free running (un-narrowed) excimer lasers operating at wavelengths below 300 nm, with limited choices of optical materials with high transmission at these wavelengths. From these catadioptric design forms, variations have been developed to accommodate changes in wavelength, increases in the numerical aperture and conversion of the imaging medium from nitrogen to ultra-high purity water and other high index fluids for immersion lithography applications. Some designs also address the need for increased working distance. This paper will discuss the use of multi-function components, the evolution of several design forms, the optical materials required, their benefits for specific applications, and the challenges they have created.
Freeform optical surfaces are defined as any non-rotationally symmetric surface or a symmetric surface that is rotated about any axis that is not its axis of symmetry. These surfaces offer added degrees of freedom tha...
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Freeform optical surfaces are defined as any non-rotationally symmetric surface or a symmetric surface that is rotated about any axis that is not its axis of symmetry. These surfaces offer added degrees of freedom that can lead to lower wavefront error and smaller system size as compared to rotationally symmetric surfaces. Unfortunately, freeform optics are viewed by many designers as more difficult and expensive to manufacture than rotationally symmetric optical surfaces. For some freeform surfaces this is true, but a designer has little or no feedback to quantify the degree of difficulty for manufacturing a surface. This paper describes a joint effort by optical Research Associates (ORA) and the Precision engineering Center (PEC) at North Carolina State University to integrate metrics related to the cost and difficulty of manufacturing a surface into the merit function that is used during the design of an optical system using Code V®. By incorporating such information into the merit function, it is possible to balance optical performance and manufacturability early in the design process.
This paper presents the design, fabrication process, and performance evaluation of a two-dimensional hydrogenated amorphous silicon (a-Si:H) n-i-p photodiode array, developed specifically for low-level light sensor ap...
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This paper presents the design, fabrication process, and performance evaluation of a two-dimensional hydrogenated amorphous silicon (a-Si:H) n-i-p photodiode array, developed specifically for low-level light sensor applications. The design of the device is simpler than conventional active-matrix-arrays based on thin-film transistor (TFT) addressing electronics, owing to the utilization of the a-Si:H switching diodes for signal readout. The discussed technological developments are aimed to minimize the leakage current and to enhance the external quantum efficiency. The current-voltage characteristics of the sensing and switching diodes are analyzed to identify the sources of the excess leakage current. The optical losses in the photodiodes with an ITO/a-SiNx:H antireffection coating have been minimized using numerical modeling. Description of the peripheral electronics and associated timing diagrams along with the results of the detector characterization, including the linearity and response time measurements, are presented and discussed.
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