| 1. |
- Anders, Berntson, et al.
(författare)
-
Dispersion management with filtering
- 1998
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We present results of analytical and numerical consideration of the pulses in a model of a DM fiber link including the fixed-frequency filters and compensating gain, both taken in the distributed approximation. Combining the variational approximation and perturbative treatment of the filtering and gain terms, we predict stationary propagation regimes. The most important new features are the absence of the minimum DM strength necessary for the existence of the pulses in the case when the average dispersion is nil or normal, and the existence of a minimum necessary normalized power in this case. These features are well corroborated by direct simulations.
|
|
| 2. |
- Anders, Berntson, et al.
(författare)
-
Dispersion management with filtering
- 1999
-
Ingår i: Optics Letters. - : Optical Society of America Inc.. - 0146-9592 .- 1539-4794. ; 24:8, s. 507-509
-
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.
|
|
| 3. |
- Dimitrevski, K., et al.
(författare)
-
Analysis of stable self-trapping of laser beams in cubic-quintic nonlinear media
- 1998
-
Ingår i: Physics Letters A. - : Elsevier. - 0375-9601 .- 1873-2429. ; 248:5-6, s. 369-376
-
Tidskriftsartikel (refereegranskat)abstract
- A numerical and analytical analysis of two-dimensional laser beam propagation in cubic-quintic nonlinear optical media demonstrates the existence of stable stationary radially symmetric modes. By means of a variational method, involving super-Gaussian trial functions and Ritz optimization, approximate stationary solutions are obtained, showing very good agreement with numerical results, even in the strongly non-linear, almost saturated, regime. The stability of the stationary modes are verified by analytical analysis and by direct numerical simulations.
|
|
| 4. |
- Malomed, B. A., et al.
(författare)
-
Decay of parametric solitons in a lossy medium with quadratic nonlinearity
- 1996
-
Ingår i: Pure and Applied Optics (Print edition) (United Kingdom). - : IOP Publishing. - 0963-9659. ; 5:6, s. 941-946
-
Tidskriftsartikel (refereegranskat)abstract
- An investigation is made into the evolution of two-wave solitons in a second-haimonic-generation system under the action of weak dissipation. Using the balance equation for the soliton energy and a previously developed variational approximation for its shape, a general evolutional equation is derived for the soliton parameters. The equation is solved explicitly for the asymptotic stage of the evolution
|
|
| 5. |
- Malomed, B. A., et al.
(författare)
-
Spatiotemporal solitons in multidimensional optical media with a quadratic nonlinearity
- 1997
-
Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - 1063-651X .- 1095-3787. ; 56:4, s. 4725-4735
-
Tidskriftsartikel (refereegranskat)abstract
- We consider solutions to the second-harmonic generation equations in two- and three-dimensional dispersive media in the form of solitons localized in space and time. As is known, collapse does not take place in these models, which is why the solitons may be stable. The general solution is obtained in an approximate analytical form by means of a variational approach, which also allows the stability of the solutions to be predicted. Then, we directly simulate the two-dimensional case, taking the initial configuration as suggested by the variational approximation. We thus demonstrate that spatiotemporal solitons indeed exist and are stable. Furthermore, they are not, in the general case, equivalent to the previously known cylindrical spatial solitons. Direct simulations generate solitons with some internal oscillations. However, these oscillations neither grow nor do they exhibit any significant radiative damping. Numerical solutions of the stationary version of the equations produce the same solitons in their unperturbed form, i.e., without internal oscillations. Strictly stable solitons exist only if the system has anomalous dispersion at both the fundamental harmonic and second harmonic (SH), including the case of zero dispersion at SH. Quasistationary solitons, decaying extremely slowly into radiation, are found in the presence of weak normal dispersion at the second-harmonic frequency
|
|
| 6. |
- Quiroga-Teixeiro, M. L., et al.
(författare)
-
Efficient soliton compression by fast adiabatic amplification
- 1996
-
Ingår i: Journal of the Optical Society of America. B, Optical physics. - : Optical Soc of America. - 0740-3224 .- 1520-8540. ; 13:4, s. 687-692
-
Tidskriftsartikel (refereegranskat)abstract
- This paper shows the possibility of obtaining fast, but still adiabatic, amplification of soliton pulses by using a rapidly increasing distributed amplification with scale lengths comparable with the characteristic dispersion length. Explicit expressions for the required distribution of this gain and the variation of the pulse width are given, and theoretical predictions have been verified by numerical simulations. The practical implementation of the compression scheme should be possible by using an active fiber with a doping proportional to the required gain distribution. A study was also made of how efficient compression of solitons can be obtained.
|
|
| 7. |
- Quiroga-Teixeiro, M. L., et al.
(författare)
-
Efficient soliton compression by fast adiabatic amplification
- 1998
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- It is shown that a properly tailored, rapidly increasing gain along the distance of propagation in a monomode fiber can provide fast but still adiabatic soliton amplification and therefore high-quality one-soliton compression for fiber lengths even shorter than the characteristic dispersive length. With the variational approach an explicit expression is given for the required variation of the inhomogeneous gain, and its validity is demonstrated by comparison with direct numerical simulations that include the calculation of the pure soliton component. It is also shown by analytical and numerical perturbation analysis that the compression scheme is stable with respect to small deviations from the ideal soliton form and gain variation. Finally, it is demonstrated that efficient soliton compression can also be obtained by cascading of instantaneous optical amplifiers in an intermediate fiber with higher dispersion, where nonlinear mode conversion preserves the soliton character of the amplified pulse. The practical implementation of these compressor schemes is discussed.
|
|
