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Zero-order non-coherent optical filtering can be performed by subtraction of images recorded with two different filters. In this paper filters are studied which differ by the average phase of certain parts in the frequency plane. Band-pass and differentiation filters can be realized in that way. 相似文献
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F. Lanzl H. Morian W. von der Osten W. Waidelich 《Zeitschrift für Physik A Hadrons and Nuclei》1968,214(5):447-456
The R2 zero-phonon absorption line 4480 Å in NaF at 4.2 °K and 23 °K is studied under uniaxial stress along 〈100〉 and 〈100〉. According to the F3 model of theR center the R2 line is found to be due to a transition between a degenerate ground state (2E) and a nondegenerate excited state (2A) of this center. Instead of a splitting into single components under stress, changes in line shape are observed which are analyzed by means of the method of moments. The zeroth and first moment of the line are calculated as functions of the magnitude of stress and temperature. The theoretical moments are found to be in good agreement with those determined from the experimental data. From a comparison of the measured moments with the theoretical expressions the stress splitting parameters are obtained which describe the removal of both the orientational and the orbital degeneracy of theR center under uniaxial stress. The corresponding strain parameters of the R2 line in NaF are compared with those in other alkali halides. 相似文献
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G. Johannson F. Lanzl W. Von Der Osten W. Waidelich 《Zeitschrift für Physik A Hadrons and Nuclei》1967,201(4):430-444
A number of zero-phonon absorption lines ofF aggregate color centers is studied inx-irradiated NaF crystals under uniaxial stress. The color centers associated with the lines are found to exhibit rhombic (D2h, D2, C2v; rotation axes along 〈110〉 and 〈100〉) and monoclinic (C2h, C2, Cs; rotation axis along 〈110〉) symmetries. The transitions of the rhombic color centers correspond to 〈100〉 and 〈110〉 dipoles, those of the monoclinic centers to 〈112〉 and 〈110〉 dipoles. The most prominent line at 5803 Å is due to a 〈112〉 dipole transition within a monoclinic color center. Several models of centers are discussed. 相似文献
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A device is described which is capable of real-time linear filtering of incoherently illuminated objects. It uses colour encoded aperture masks to multiplex the filtering channel. 相似文献
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Johannson G. Lanzl F. Mödl H. von der Osten W. Waidelich W. 《Zeitschrift für Physik A Hadrons and Nuclei》1968,209(1):1-12
The spectral resolution of quartz crystals bent to a cylindrical form by means of four rods was investigated with CuKα radiation in a reflection type arrangement. The crystal adjustment was made optically using interference fringes. With the crystal bent to a circular cylinder the deviations from exact focusing inherent to the Johann case could be measured and were found to be in agreement with theory. — Crystals bent to a logarithmic spiral have also been studied. With a 24 mm broad reflecting area (mean radius of curvature 1 m; (13¯40)-plane) an uncorrected full width at half maximum intensity of 0.43 XU or 2.25 eV was observed for the CuKα 1 line, in agreement with double crystal spectrometer measurements. 相似文献
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G. Baumann F. Lanzl W. von der Osten W. Waidelich 《Zeitschrift für Physik A Hadrons and Nuclei》1966,197(4):367-372
Uniaxial stress splitting experiments suggest the 5456 Å zero-phonon line in NaF to be due to a transition of the F 3 + center. The line and a number of phonon-assisted peaks are observed in absorption and emission. 相似文献
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