The Infrared Atmospheric Sounder Interferometer (IASI) is a Fourier Transform Spectrometer (FTS) working in the [3.6 mu m, 15.5 mu m] range, dedicated to Numerical Weather Prediction (NWP), atmospheric chemistry and c...
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ISBN:
(纸本)9780819496911
The Infrared Atmospheric Sounder Interferometer (IASI) is a Fourier Transform Spectrometer (FTS) working in the [3.6 mu m, 15.5 mu m] range, dedicated to Numerical Weather Prediction (NWP), atmospheric chemistry and climate monitoring. The second flight model (2 out of 3) is now in orbit and operational, as a payload of the MetOp-B satellite. A new generation of instrument (IASI-NG) to continue the IASI mission with increased performances is currently investigated by the French Space Agency (CNES). The performance objective is mainly a spectral resolution and a radiometric error divided by two compared with the IASI ones. Many different concepts of FTS were studied to try to fulfill these challenging requirements. This paper presents the different envisaged optical architecture and associated trade off. The major issue of the concept is to manage the so-called self-apodization of the interferogram and the associated degradation of the spectral resolution induced by the wider Field of View (FoV) and the longer optical Path Difference (OPD). Increasing these two quantities have very constraining consequences on the optical architecture. Another critical point is the control of straylight which is quite severe and which has been taken into account early in the opticaldesign. To assess the performances of the interferometer, different optical models were built combining analytical approach with ray tracing technics. We will describe the impacts of the demanding spectral requirements on the optical components and our analyses based on these models will be presented.
Several common impediments to successful lensdesign can be removed by application of new techniques. These involve using information that has long been calculated during the design process, but then discarded. Proble...
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ISBN:
(纸本)9780819472809
Several common impediments to successful lensdesign can be removed by application of new techniques. These involve using information that has long been calculated during the design process, but then discarded. Problems so addressed include the nuisance of discovering ray failures in the starting configuration, and that of tolerance desensitization, among others.
A lensdesign having constant working distance while having variable recording depth for micro holographic data storage system has been proposed. Variation of focal length is suppressed for the entire depth within 1% ...
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ISBN:
(纸本)9780819482822
A lensdesign having constant working distance while having variable recording depth for micro holographic data storage system has been proposed. Variation of focal length is suppressed for the entire depth within 1% which enables focusing and tracking servoing without changing servo parameters.
Aspheric mould design includes the top-down design and reversal design. In this paper, a new framework of reversal design is proposed combining with cloud supported collaborative design (CSCD) based on aspheric measur...
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ISBN:
(纸本)9780819496911
Aspheric mould design includes the top-down design and reversal design. In this paper, a new framework of reversal design is proposed combining with cloud supported collaborative design (CSCD) based on aspheric measurement. The framework is a kind of collaborative platform, which is composed of eight modules, including the computerized aspheric precision measurement module (CAPM), computer-aided opticaldesign of aspheric lens system (CAOD), computer-aided design of lens mould (CADLM), FEM(finite element method) simulation of lens molding module (FEMLM), computer-aided manufacture of lens & moulds (CAMLM), measurement data analysis module (MDAM), optical product lifecycle management module (OPLM) and cloud computing network module (CCNM). In this framework, the remote clients send an improved requirement or fabrication demand about opticallens system through CCNM, which transfers this signal to OPLM. In OPLM, one main server is in charge of the task distribution and collaborative work of other six modules. The first measurement data of aspheric lens are produced by clients or our proposed platform CAPM, then are sent to CAOD for optimization and the electronic drawings of lens moulds are generated in CADLM module. According the design drawings, the FEMLM could give the lens-molding simulation parameters through FEM software. The simulation data are used for the second design of moulds in CADLM module. In this case, the moulds could be fabricated in CAMLM by ultra-precision machine, and the aspheric lens could be also produced by lens-molding machine in CAMLM. At last, the final shape of aspheric lens could be measured in CAPM and the data analysis could be conducted in MDAM module. Through the proposed framework, all the work described above could be performed coordinately. And the optimum design data of lens mould could be realized and saved, then shared by all the work team.
We introduce a closed-form formula to design a spherochromatic collimator singlet lens. The light for three different wavelengths is collimated at the output of the lens. We test the singlet lens using ray-tracing met...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
We introduce a closed-form formula to design a spherochromatic collimator singlet lens. The light for three different wavelengths is collimated at the output of the lens. We test the singlet lens using ray-tracing methods and we find satisfactory results for three different wavelengths.
Genetic algorithm and its application in lensdesign is studied. A new algorithm is presented which includes a genetic algorithm (GA) and damped least square (DLS) method. The convergence property of GA in lensdesign...
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ISBN:
(纸本)0819422517
Genetic algorithm and its application in lensdesign is studied. A new algorithm is presented which includes a genetic algorithm (GA) and damped least square (DLS) method. The convergence property of GA in lensdesign is demonstrated. A GA. generated design is obtained without artificial intervention. The aberration correction has to be done by DLS, and the result is close to the starting configuration generated by GA.
Using the concept of matrix theory for lensdesign, a triplet lens can be replaced by a singlet lens which has an equivalent system matrix without changing its optical performance. Then, using third order Siedel's...
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ISBN:
(纸本)081941249X
Using the concept of matrix theory for lensdesign, a triplet lens can be replaced by a singlet lens which has an equivalent system matrix without changing its optical performance. Then, using third order Siedel's first aberration coefficient of the singlet lens is equal to zero, and the focal length and the physical length of the triplet lens are kept constant as constraints, an algebraic technique for optimizing a triplet lens is derived. Results show that this new optimizing technique is more effective than other conventional techniques for optimizing a triplet lens in the case of plane waves.
A zoom objective lens for a multi-layer optical recording has been designed. A newly proposed optical power arrangement enables varying back focal length while focal length invariant by a linear movement of single zoo...
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ISBN:
(纸本)9780819492036
A zoom objective lens for a multi-layer optical recording has been designed. A newly proposed optical power arrangement enables varying back focal length while focal length invariant by a linear movement of single zooming component. The zoom lens is implemented into multi-layer and multi-bit holographic recording system employing 405 nm blue lasers.
In this paper, we present a new fisheye projection lens for 8 perforation 70 mm format film. The lens has an aperture of F/2.4 and a total field of view of 163 degree(s). We discuss design considerations, and compare ...
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ISBN:
(纸本)081941249X
In this paper, we present a new fisheye projection lens for 8 perforation 70 mm format film. The lens has an aperture of F/2.4 and a total field of view of 163 degree(s). We discuss design considerations, and compare predicted with measured performance data.
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