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Zhang J.-X.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Chinese Optics | Year: 2012

The developing status of large aperture ground-based telescopes is reviewed in this paper. The significance of bigger apertures for telescopes and their main technological approaches are expatiated and the summary on appliance values of modern large aperture telescopes is given. Then, it introduces five kinds of modern typical large telescope systems, which represent the topmost technological level. The key structures and technologies of large telescopes about mount, telescope tubes, primary mirror supports and secondary mirror assemblies are disscussed. Finally, it summarizes the developing trends of the large aperture ground-based telescopes and points out that some of the optical systems in the telescopes have been changed from coaxial systems to off-axial systems, while they are better application prospects. Source

Li D.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Stockman M.I.,Georgia State University
Physical Review Letters | Year: 2013

We consider theoretically the spaser that is excited electrically via a nanowire with ballistic quantum conductance. We show that, in the extreme quantum regime, i.e., for a single conductance-quantum nanowire, the spaser with a core made of common plasmonic metals, such as silver and gold, is fundamentally possible. For ballistic nanowires with multiple-quanta or nonquantized conductance, the performance of the spaser is enhanced in comparison with the extreme quantum limit. The electrically pumped spaser is promising as an optical source, nanoamplifier, and digital logic device for optoelectronic information processing with a speed of ∼100 GHz to ∼100 THz. © 2013 American Physical Society. Source

Xue Q.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Applied Optics | Year: 2011

A low-cost, broadband, astigmatism-corrected Czerny-Turner arrangement with a fixed plane grating is proposed. A wedge cylindrical lens is used to correct astigmatism over a broadband spectral range. The principle and method of astigmatism correction are described in detail. We compare the performance of this modified Czerny-Turner arrangement with that of the traditional Czerny-Turner arrangement by using a practical Czerny-Turner imaging spectrometer example. © 2011 Optical Society of America. Source

Wang X.-K.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Chinese Optics | Year: 2013

For the purpose to decrease the misalignment error from a testing aspheric surface by Subaperture Stitching Interferometry(SSI), a translated error compensation method is proposed to subtract the misalignment error from each phase detum and to stitch multi-subapertures precisely. The basic principle and process of the method are researched, and a compensation mode is established based on the mode search algorithm. The experiment is carried on for an off-axis SiC aspheric mirror with a clear aperture of 230 mm×141 mm, the phase data of the whole aperture are stitched precisely and the figure error is compensated by eliminating the misalignment error. For the comparison and validation, the asphere mirror is also tested by null compensation method, and the relative errors of PV and RMS are 0.57% and 2.74%, respectively. Source

Sun H.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Chinese Optics | Year: 2013

On the basis of the characteristics of an airborne electro-optical platform, six coordinate systems were established and eight linear coordinate transformations were performed. A coordinate transformation model from a camera sensor plane to geodetic coordinate systems was established by using linear coordinate transformation, and the computation formula of geodetic coordinate of the target was derived based on the transformation of different coordinates. The influence of target localization due to various error factors was discussed, and the localization error was analyzed with Mont Carlo method. The experimental results show that the target location is affected by aircraft position errors, aircraft attitude errors and EO platform pose errors, among which the aircraft position errors are transferred directly into the target location, and the aircraft attitude errors and EO platform pose errors are tranferred scaling with the range of 10-4~10-2 to the target location. This method is efficient and useful to the localization of targets for airborne EO platforms. Source

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