| 1. |
- Akhmediev, N.N., et al.
(författare)
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Radiationless optical solitons with oscillating tails
- 1994
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018. ; 110:5-6, s. 540-544
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Tidskriftsartikel (refereegranskat)abstract
- We investigate, analytically and numerically, stationary soliton-like pulse propagation in nonlinear optical fibres, taking into account the effects of fourth order dispersion. A new type of stationary stable soliton-like solution is found. A unique feature of this type of solution is their unusual asymptotic behaviour (oscillating tails). © 1994.
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| 2. |
- Ankiewicz, A., et al.
(författare)
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Dark soliton pairs in fiber couplers
- 1994
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Ingår i: Optics Communications. - 0030-4018. ; 111:1-2, s. 116-122
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the possible stationary states formed by pairs of dark solitons propagating in dual-core optical fibers, i.e. in a nonlinear coupler. These are local disturbances on a constant background. We find new dark soliton states, characterize them and show that they differ from the soliton states consisting of coupled bright solitons in several ways. © 1994.
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| 3. |
- Höök, Anders, 1962, et al.
(författare)
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Soliton instabilities and pulse compression in minimum dispersion fibers
- 1994
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Ingår i: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197 .- 1558-1713. ; 30:8, s. 1831-1841
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Tidskriftsartikel (refereegranskat)abstract
- A new stability of ultrashort pulses in optical fibers is demonstrated which, together with a recently discovered modulation instability, is shown to deteriorate a pulse compression mechanism. The pulse compression is analyzed in detail by means of a perturbation technique.
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| 4. |
- Karlsson, Magnus, 1967, et al.
(författare)
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A variational approach to optical soliton collisions
- 1994
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Ingår i: Physica Scripta. - : IOP Publishing. - 1402-4896 .- 0031-8949. ; 50:3, s. 265-270
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Tidskriftsartikel (refereegranskat)abstract
- The mathematical analogy between the nonlinear Schrödinger equations describing propagation of temporal soliton pulses in optical fibres, and propagation of spatial soliton beams in planar optical wave guides is discussed. A straightforward variational method, based on trial functions and Rayleigh-Ritz optimization, is demonstrated and applied to incoherent interaction of solitons. We study incoherent soliton interaction in a wavelength-multiplexed optical-fibre communication system, as well as the analogous problem for crossed optical beams in a planar waveguide. The predictions of the variational approach are also shown to be in good agreement with numerical simulation results and with experiments.
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| 5. |
- Karlsson, Magnus, 1967
(författare)
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Nonlinear Propagation of Optical Pulses and Beams
- 1994
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The propagation of optical beams and pulses under the influence of nonlinear effects is characterized by a rich variety of phenomena and many potentially important applications. We analyse two main topics in this context: nonlinear beam propagation, and nonlinear pulse propagation in optical fibers. The propagation of an optical beam is characterized by diffractive broadening. For Kerr-media, in which the refractive index increases with beam intensity, at a certain intensity, the beam may induce its own waveguide and propagate without broadening. For higher intensities, the nonlinearly induced refractive index causes self-focusing and in some cases even collapsing singularities. We demonstrate in this work that an analytical variational approach describes the dynamics of nonlinear beam propagation very well, in particular with respect to the phase modulation dynamics, which previous approaches are found to describe erroneously. The collapse can be removed by allowing the refractive index to saturate. Beam dynamics in saturable nonlinear media is therefore an important issue. Using the variational method, we manage to reproduce the essential features from numerical simulations, and to give a complete picture of optical beam dynamics in saturable nonlinear media. Another important effect in nolinear media is the modulational instability, which is well-known to break up broad beams into filaments. However, this instability can occur only in nonlinear focusing media. Considering a pulsed beam with a defocusing-in-time and focusing-in-space nonlinearity, we show that temporal breakup is possible due to the spatial instability, despite the fact that a purely temporal modulation is stable.
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| 6. |
- Karlsson, Magnus, 1967
(författare)
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Optical fiber-grating compressors utilizing long fibers
- 1994
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018. ; 112:1-2, s. 48-54
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Tidskriftsartikel (refereegranskat)abstract
- The properties of optical fiber-grating compressors have been investigated numerically, considering fibers ten times longer than in previous studies. It is found that such long fibers yield substantially better compression than the previously investigated short ones. Also considerde are the sensitivity of pulse shape on the compression by using Gaussian-, parabolic- and sech- shaped pulses as initial conditions. © 1994.
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| 7. |
- Karlsson, Magnus, 1967, et al.
(författare)
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Soliton-like pulses governed by fourth order dispersion in optical fibers
- 1994
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018. ; 104:4-6, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- The properties of pulse propagation in a nonlinear fiber including negative fourth order dispersion added to anomalous second order dispersion are analyzed numerically and analytically. An exact localized analytical solution is presented, and using an approximate variational method, an entire family of stationary approximate solutions is also obtained. These solutions are found to be in excellent agreement with numerical simulations.
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