1. |
- Setala, T., et al.
(författare)
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Complete electromagnetic coherence in the space-frequency domain
- 2004
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 29:4, s. 328-330
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Tidskriftsartikel (refereegranskat)abstract
- We show that the following properties of a random electromagnetic field are equivalent: (i) the field is spatially completely coherent in the sense of the recently introduced electromagnetic degree of coherence and (ii) the electric cross-spectral density tensor factors in the two spatial variables.
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2. |
- Abdullaev, Farakhulla, et al.
(författare)
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Zeno effect and switching of solitons in nonlinear couplers
- 2011
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Ingår i: Optics Letters. - : Optical Society of America. - 0146-9592 .- 1539-4794. ; 36:23, s. 4566-4568
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Tidskriftsartikel (refereegranskat)abstract
- The Zeno effect is investigated for soliton type pulses in a nonlinear directional coupler with dissipation. The effect consists in increase of the coupler transparency with increase of the dissipative losses in one of the arms. It is shown that localized dissipation can lead to switching of solitons between the arms. Power losses accompanying the switching can be fully compensated by using a combination of dissipative and active (in particular, parity-time-symmetric) segments.
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3. |
- Albert, Jacques, et al.
(författare)
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Grating formation in pure silica-core fibers
- 2002
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 27:10, s. 809-811
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Tidskriftsartikel (refereegranskat)abstract
- Strong grating formation in pure silica-core fibers by use of 193-nm ArF-laser radiation is reported. Unsaturated refractive-index changes of Deltan similar to 0.3 X 10(-3) were observed in nontreated fiber, and changes of Deltan similar to 0.5 X 10(-3) were observed in fibers with a high hydroxyl concentration. Possible mechanisms of photosensitivity in pure silica-core fibers are discussed.
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4. |
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5. |
- Alessi, D, et al.
(författare)
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Gain-saturated 10.9 nm tabletop laser operating at 1 Hz repetition rate
- 2010
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Ingår i: Optics Letters. - : Optical Society of America. - 0146-9592 .- 1539-4794. ; 35:3, s. 414-6
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Tidskriftsartikel (refereegranskat)abstract
- We report the demonstration of a gain-saturated 10.9 nm tabletop soft x-ray laser operating at 1 Hz repetition rate. Lasing occurs by collisional electron impact excitation in the 4dS01-->4pP11 transition of nickel-like Te in a line-focus plasma heated by a chirped-pulse-amplification Ti:sapphire laser. With an average power of 1muW and pulse energy up to approximately 2microJ, this laser extends the ability to conduct tabletop laser experiments to a shorter wavelength.
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6. |
- Anders, Berntson, et al.
(författare)
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Dispersion management with filtering
- 1999
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Ingår i: Optics Letters. - : Optical Society of America Inc.. - 0146-9592 .- 1539-4794. ; 24:8, s. 507-509
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Tidskriftsartikel (refereegranskat)abstract
- With regards to their potential to improving the pulse-based regimes in optical communication networks, dispersion-managed solitons in a fiber link including guiding filters and compensating gain were investigated. Combining the variational approximation and the perturbative treatment of the filtering and gain, stationary regimes are predicted. Among other features, the minimum map strength necessary for the existence of the pulses when path-averaged dispersion (PAD) is zero or normal is absent, rather, a minimum necessary normalized power for any PAD exists.
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7. |
- Anders, Berntson, et al.
(författare)
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Power dependence of dispersion-managed solitons for anomalous, zero, and normal path-average dispersion
- 1998
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Ingår i: Optics Letters. - Goteborg, Sweden : Chalmers Tekniska Hogskola. - 0146-9592 .- 1539-4794. ; 23:12, s. 900-902
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We determine the power dependence of dispersion-managed solitons on map strength and average dispersion, using a combination of numerical simulations and the variational approach. In particular, we investigate the behavior near zero dispersion and identify the region of existence of dispersion-managed solitons in the average normal-dispersion regime.
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8. |
- Andersen, Torben, et al.
(författare)
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Neural networks for image-based wavefront sensing for astronomy
- 2019
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Ingår i: Optics Letters. - : Optical Society of America. - 0146-9592 .- 1539-4794. ; 44:18, s. 4618-4621
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Tidskriftsartikel (refereegranskat)abstract
- We study the possibility of using convolutional neural networks for wavefront sensing from a guide star image in astronomical telescopes. We generated a large number of artificial atmospheric wavefront screens and determined associated best-fit Zernike polynomials. We also generated in-focus and out-of-focus point-spread functions. We trained the well-known “Inception” network using the artificial data sets and found that although the accuracy does not permit diffraction-limited correction, the potential improvement in the residual phase error is promising for a telescope in the 2–4 m class.
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9. |
- Ansari, Nazanin, et al.
(författare)
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Multicolor filter all-garnet magneto-optical photonic crystals
- 2012
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 37:17, s. 3552-3554
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a multicolor optical filter and isolator based on a double-cavity magneto-optical (MO) photonic crystal. Being grown as a heteroepitaxial all-garnet multilayer, it compromises a strong MO response and high optical transmittance. Low-loss, high Faraday rotation passbands as well as strong light rejection within the stop band were achieved by optimization of distance between cavities and repetition number of distributed Bragg reflectors.
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