Theory of nonlinear pulse propagation in optical waveguides (original) (raw)
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Diminishing Dispersive And Nonlinear Effects Of Optical Soliton Using Group Velocity Dispersion
2013
The main objective of our work is to investigate the ultra-short optical soliton pulses dynamics in amplifying optical fibers with smooth and strong group velocity dispersion. It is well known that the self-frequency shift effect shifts the spectrum of a soliton pulse from under the gain line profile and is one of the main factors that limits the maximum energy and minimum duration of the output pulses. We analyse the possibility of using soliton to weaken undesirable effect for variable nonlinearity and group velocity dispersion. As follow from our simulations it is possible to capture the ultra-short optical soliton by a dispersion formed in an amplifying optical fiber. This process makes it possible to accumulate an additional energy in the soliton dispersion and reduce significantly the soliton pulse duration. In analysis and study of the pulse propagation in optical fiber of a new nonlinear effect, solitons pass through localized fibers and the effect of non-linearity and dispersion of the pulse propagation causes temporal spreading of pulse and it can be compensated by non-linear effect using different types of pulse including Gaussian and Super-Gaussian pulses.
Spatial solitons in media with slow nonlinearity
Fifth Symposium Optics in Industry, 2006
Light beams and light pulses (in general any wave packet) tend, in a natural way, to broad as they propagate in a linear material. Optical solitons are beams that do not suffer broadening as they propagate in a nonlinear material. Spatial optical solitons are beams where the natural diffraction is compensated by a self induced refractive index change in the media, creating its own waveguide.
Nonlinear dynamics of femtosecond optical solitary wave propagation at the zero dispersion point
IEEE Journal of Quantum Electronics, 1995
OLITONS are pulse-like waves that propagate in non-S linear dispersive media without any change in shape or intensity due to a deficate balance between the nonlinear and dispersive effects. Solitons belong to a wider class of localized nonlinear traveling waves, the class of the so-called solitary waves [l]. In nonlinear optical fibers, propagation of a great variety of solitary waves, namely, solitons [2], shock waves [3], kink and antikink waves [4], is predicted. The propagation d sokitons and shock waves, which are usually called bright and dark solitons, respectively, in the optical soliton literature [5], [63, has also experimentally been verified [71, 181. Nonlinear pulse prupagation at the zero dispersion point, uxmspoading to zero s8cond-order (or p u p velocity) dispersion, is desirable m optical communication systems because them the power required for generating (bright) solitons is sigRiticaRtly lawer €51, Id]. The corresponding nonlinear evolution equation (NEE), for the complex envelqk of the ekmie field distribution, results directly from the nonlinear Schrzktinger Gqultion (NLS) [5], [6],, by neglecting the S e c o n d d r d i s p i e n term and taking into account the thirdsrder linear dispersion term. This equation has been analyzed, by using numerical techniques, by various groups in the past [91-[13], for the usual case of a positive thirdorder &persim. Ntice that the effects of fiber loss [14] and axial inhomogeneity E 151 have also been examined. Analytical mults, for the case of dark solitons, have been obtained Manusuipt d v e Athens, Greece. IEEE Log Number 9409267.
Soliton interaction in a nonlinear waveguide in the presence of resonances
Nonlinear Guided Waves and Their Applications, 2001
The simultaneous propagation of two optical pulses through a nonlinear dispersive medium composed of a resonant three-level system is investigated. By choosing a soliton of area 4 and order Nϭ2 at the pump frequency, together with a weaker pulse with a sech profile at the signal frequency, we show that the pump soliton breaks up into a pair of solitary waves which are cloned to the signal frequency. Due to a combination of coherent population trapping and nonlinear dispersive effects, the pair interacts in a repulsive fashion so that the taller wave travels faster than the shorter one.
Physical Review A, 2020
We show theoretically that highly dispersive optical media characterized by a Kerr nonlinear response may support the existence of quartic and dipole solitons in the presence of the self-steepening effect. The existence and stability properties of these localized pulses are examined in the presence of all the material parameters. Regimes for the modulation instability of a continuous-wave signal propagating inside the nonlinear medium are investigated and an analytic expression for the gain spectrum is obtained and shown to be dependent on the self-steepening parameter in addition to second-and fourth-order group velocity dispersion parameters. Self-similar soliton solutions are constructed for a generalized nonlinear Schrödinger equation with distributed second-, third-, and fourth-order dispersions, self-steepening nonlinearity, and gain or loss describing ultrashort pulse propagation in the inhomogeneous nonlinear media via the similarity transformation method. The evolutional dynamics of the self-similar structures are investigated in a periodic distributed waveguide system and an exponential dispersion decreasing waveguide.
Propagation of a soliton in a nonlinear waveguide with dissipation and pumping
Optics Communications, 1987
Generation of nonsoliton wave field (radiation) by pumping pulses compensating dissipative damping of a soliton moving in a nonlinear optical waveguide is investigated in the framework of a simple model based on a perturbed nonlinear Schriidinger equation. The stationary level of radiation is found, and a condition providing efficiency of the waveguide, i.e. the number of the radiation light quanta being small in comparison with the number of quanta bound in the soliton, is obtained.
Journal of Optics A: Pure and Applied Optics, 1999
Properties of two pulses propagating simultaneously in different dispersion regimes, anomalous and normal, in a Kerr-type planar waveguide are studied in the framework of the nonlinear Schrödinger equation. It is found that the presence of the pulse propagating in a normal dispersion regime can cause termination of catastrophic self-focusing of the pulse with anomalous dispersion. It is also shown that the coupling between pulses can give rise to spatiotemporal splitting of the pulse propagating in anomalous dispersion regime, but it does not necessarily lead to catastrophic self-focusing of the pulse with normal dispersion. For the limiting case when the dispersive term of the pulse propagating in normal dispersion regime can be neglected an indication (based on the variational estimation) of a possibility of a stable self-trapped propagation of both pulses is obtained. This stabilization is similar to the one which was found earlier in media with saturation-type nonlinearity.
Solitons are the solutions of certain nonlinear partial differential equations, with interesting properties. Because of a balance between nonlinear and linear effects, the shape of soliton wave pulses does not change during propagation in a medium. In the following seminar , I present the general properties of solitons and the way these can be used in physical applications. Focusing on optical solitons, both temporal and spatial solitons are presented together with the physical effects that make them possible. The advantages and difficulties regarding soliton based optical communication are explained. Furthermore, the potential future application of solitons and soliton interactions for ultra fast optical logical devices is introduced.