| 1. |
- Anders, Berntson, et al.
(författare)
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Self-phase modulation in dispersion compensated optical fibre transmission systems
- 1996
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Ingår i: Optics Communications. - : Elsevier. - 0030-4018 .- 1873-0310. ; 130:1-3, s. 153-162
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Tidskriftsartikel (refereegranskat)abstract
- An analysis is made of the influence of self-phase modulation on optical fibre communication systems where the chromatic dispersion is compensated for by a dispersion compensation fibre. In particular we derive a simple and useful expression for the optimal fibre length in the presence of nonlinearities.
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| 2. |
- Beck, M., et al.
(författare)
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A pulse-train laser driven XUV source for picosecond pump-probe experiments in the water window
- 2001
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 190:06-jan, s. 317-326
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Tidskriftsartikel (refereegranskat)abstract
- We describe the development of a table top soft X-ray source based on a laser produced plasma. The plasma is produced by a Nd:YLF pulse-train laser which delivers pulse trains of up to 400 pulses each of about 25 ps duration, Number and energy of the micropulses are fully computer controlled adjustable for an optimum interaction with a rotating solid target. Spectral, spatial and temporal characteristics of the X-ray emission from Mylar and copper targets have been studied. A calibrated back-illuminated CCD camera together with a slit grating spectrograph were utilized for the measurement of the absolute soft X-ray photon fluxes. The temporal measurements were performed using a streak camera while the plasma size was measured with a zone plate. An application of the system in a X-ray absorption experiment is shown, The advantages of the system in view of possible optical pump and soft X-ray probe experiments will be discussed.
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| 3. |
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| 4. |
- Friberg, Ari T., et al.
(författare)
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Focal shifts of converging diffracted waves of any state of spatial coherence
- 2001
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 196:06-jan, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the focusing of wave fields of any state of coherence by systems with low Fresnel numbers. We study the optical intensity on the axis in the focal region. The dependence of the focal shift and of the maximum on-axis intensity on the state of coherence is examined for some model fields.
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| 5. |
- Karlsson, G., et al.
(författare)
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Q-switching of an Er-Yb : glass microchip laser using an acousto-optical modulator
- 2003
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 217:06-jan, s. 317-324
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Tidskriftsartikel (refereegranskat)abstract
- We present a compact Q-switched Er-Yb:glass microchip laser operating at the wavelength of 1.535 mum using an acousto-optical modulator. A Q-switched peak power of 325 W with a pulse-duration of 38 ns and a pulse-to-pulse jitter of less then 10 ns was achieved. Well-controlled pulses were obtained for repetition rates up to 10 kHz while the maximum pulse energy was 12 muJ. The experimental results are compared with theoretical analysis, which shows how to optimize the laser as well as fundamental limitations.
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| 6. |
- Mohan, N.K., et al.
(författare)
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Electronic shearography applied to static and vibrating objects
- 1994
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 108:4-6, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- An optical shearography configuration is presented which can be used for the measurement of slope change for static and vibrating objects in real time. Displacement and vibration amplitude fields are extracted from the shear data, which is an useful property in noise environments. In a Michelson interferometer set-up the two arms are provided with a phase-shift mirror and a bias modulation mirror to carry out the numerical evaluation of the measured deformation. Experimental results for an edge- clamped aluminium plate are presented
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| 7. |
- Norman, P., et al.
(författare)
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Two-photon absorption in five-membered heteroaromatic oligomers
- 1999
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 168:1, s. 297-303
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Tidskriftsartikel (refereegranskat)abstract
- Structure-to-property relations for the two-photon absorption intensities of oligothiophenes, oligopyrroles, and oligofurans have been studied using ab initio response theory. Power law dependences of the two-photon absorption intensities with respect to the length of the oligomers have been revealed, and localization lengths at which the intensities are completely dominated by one single state are found.
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| 8. |
- Ostlund, P., et al.
(författare)
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Radiometry and far-zone polarization for partially coherent electromagnetic planar sources
- 2001
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 197:03-jan, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Making use of the rigorous vectorial far-field theory the generalized radiance of a stationary electromagnetic planar source is derived and expressions for the radiant intensity and the radiant emittance are introduced in terms of the spatial coherence properties of the source. A method for calculating the degree of polarization of the field in the far zone of an electromagnetic planar source is put forward and two examples demonstrating the technique are worked out.
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| 9. |
- Paakkonen, P., et al.
(författare)
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Partially coherent Gaussian pulses
- 2002
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 204:06-jan, s. 53-58
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Tidskriftsartikel (refereegranskat)abstract
- The concept of a plane-wave pulse with a Gaussian spectrum and a Gaussian distribution of correlations between different frequency components is introduced. The temporal coherence properties of such a pulse are related to the spectral coherence properties and equivalence relations between pulses with different spectral and temporal correlation parameters are established.
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| 10. |
- Petermann, Ingemar, et al.
(författare)
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Limitations of the interferometric side diffraction technique for fibre Bragg grating characterization
- 2002
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 201:4-6, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- We make a quantitative investigation of the interferometric side diffraction technique for characterization of fibre Bragg gratings. As opposed to more commonly used non-interferometric alternatives, this method also allows for determination of the grating's distributed phase. It is shown that for weak gratings the detected power and phase are directly proportional to the amplitude and phase of the refractive index modulation in the fibre. While the phase measurement is only limited by the amount of noise present, the relation between modulation amplitude and detected power becomes non-linear when using small probe beam wavelengths and gratings with a modulation depth Deltan approximate to 10(-3) and above. This behavior is inherent to the side diffraction and thus care has to be taken when performing apodization measurements on very strong gratings. The sensitivity to noise is briefly discussed and using a crude estimate for the noise level. the theory indicates that this method is suitable down to a grating modulation depth of at least Deltan approximate to 10(-5).
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