| 1. |
- Svanberg, Sune, et al.
(författare)
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Applications of terawatt lasers
- 1994
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Ingår i: LASER SPECTROSCOPY - XITH INTERNATIONAL CONFERENCE. - : AIP. - 1551-7616 .- 0094-243X. - 1563962624 ; :290, s. 264-269
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Konferensbidrag (refereegranskat)
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| 2. |
- Genoud, Guillaume, et al.
(författare)
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XUV digital in-line holography using high-order harmonics
- 2008
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 90:3-4, s. 533-538
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in Undetermined A step towards a successful implementation of time-resolved digital in-line holography with extreme ultraviolet (XUV) radiation is presented. Ultra-short XUV pulses are produced as high-order harmonics of a femtosecond laser and a Schwarzschild objective is used to focus harmonic radiation at 38 nm and to produce a strongly divergent reference beam for holographic recording. Experimental holograms of thin wires are recorded and the objects reconstructed. Descriptions of the simulation and reconstruction theory and algorithms are also given. Spatial resolution of a few hundreds of nanometers is potentially achievable, and the micrometer resolution range is demonstrated.
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| 3. |
- Golman, Klaes, et al.
(författare)
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13C-angiography.
- 2002
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Ingår i: Academic Radiology. - 1878-4046. ; 9:Suppl 2, s. 507-510
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Tidskriftsartikel (refereegranskat)
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| 4. |
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| 5. |
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| 6. |
- Abramson, N, et al.
(författare)
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Light-in-flight recording. 5: Theory of slowing down the faster-than-light motion of the light shutter
- 1989
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Ingår i: Applied Optics. - 2155-3165. ; 28:4, s. 759-765
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Tidskriftsartikel (refereegranskat)abstract
- Light-in-flight recording by holography uses a picosecond pulse for the reference beam, which like a sheet of light intersects the hologram plate and produces a sensitivity area that with a speed faster than light moves over the plate like a light shutter. If, however, the front of the reference pulse by diffraction in a grating is tilted relative to its direction of motion, the velocity of the light shutter can be slowed down resulting in increased recording time. The practical result using a reflection grating was a true recording that corresponded to a time compression of two to one. To minimize distortions of the recorded pulse shape we studied intersections that are identical for apparent (ellipsoidal) and true (spheroidal) wavefronts.
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| 7. |
- Berrocal, Edouard, et al.
(författare)
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High-contrast imaging through scattering media using structured illumination and Fourier filtering
- 2016
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Ingår i: Optics Letters. - 0146-9592. ; 41:23, s. 5612-5615
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Tidskriftsartikel (refereegranskat)abstract
- We show in this Letter a novel approach for high-contrast imaging through scattering media by combining structured illumination and Fourier filtering (SIF). To assess the image contrast enhancement at different image spatial frequencies, the modulation transfer function is calculated for four detection schemes: (1) no filtering, (2) Fourier filtering, (3) structured illumination, and (4) SIF filtering. A scattering solution consisting of D = 7.3 μm polystyrene spheres immersed in distilled water and illuminated at λ = 671 nm is used here. We demonstrate the possibility of obtaining, with SIF, an image contrast up to 60% at an optical depth of OD = 10, improving the contrast by a factor of 40 over conventional transmission imaging.
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| 8. |
- Breidegard, Björn, et al.
(författare)
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Raytracing in the compensation of the peripheral optics of the eye
- 2000
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Ingår i: Historielärarnas Förenings Årsskrift. - 0439-2434.
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: Many people with a visual impairment have only peripheral vision. However, there is limited knowledge of the peripheral optics of the eye and only some measurements are available in this field. Methods: We simulated the paths of peripheral rays through the eye by means of raytracing. Five programs were compared. The OSLO raytracing software proved to be not only the best one in these circumstances but we also found it very well suited to our purpose. Remaining uncertainties are entirely due to a lack of input data about the peripheral part of the optical system of the eye. We designed compensatory optics on the basis of the test results. Results: Lenses have been manufactured in accordance with the calculations made by the program for angles of incidence of 20, 40, and 60 degrees. The lenses are high compensation astigmatic lenses. The results of perimeter examinations of changes in peripheral vision using attachment optics were inconclusive, while tests of the lenses as attachments in front of a fundus camera produced successful preliminary results. Conclusion: The next step is to test peripheral vision compensatory optics in traffic situations (driving simulator). At the same time attempts are being made to find methods and instruments for measuring the peripheral optics of the eye. Keywords: astigmatism, central scotoma, raytracing, macula degeneration, peripheral vision.
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| 10. |
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