Study Of The Influence Of Loss On Optical Lattice Soliton And Its Compensation Scheme

It is of great scientific importance and practical value to study methods and techniques of the flow of light propagation in periodic photonic structures. Especially,because of the unique features of the periodic photonic lattice, it can be effectively used to make high-performance devices based on totally new theories and those would have been otherwise impossible. Therefore, it has important uses in the field of optics communication. The propagation of soliton in nonlinear Kerr optical lattice with harmonic modulation of refractive index is investigated analytically and numerically in this paper. And some innovative research results have been worked out.The formation conditions of lattice soliton from Gauss beam of its stable propagation are obtained. It also analyses the influence of soliton propagation because of media loss. According to the nonlinear Schr?dinger equations, by which propagation of optic lattice soliton is governed, the variational principle is applied to deduce the evolution equations of lattice soliton's primary parameters. And the influence of media loss is studied by further analysis. It is shown that lattice soliton can propagation in different formats if the different initial parameters have decided. It is shown that the media loss reduce the nonlinear effects, disturbing the balance between the diffraction and nonlinear effects. As a result, the beam width begins to increase with propagation, the lattice soliton finally disappeared. Soliton propagate in such an environment that is analogous to temporal soliton traveling in fiber.In addition, one new method that the longitudinal depth of the modulation is used to compensate media loss is proposed. It is analogous to the propagation properties of soliton in fibers with slowly decreasing dispersion. Under the condition that the beam propagates with media loss, demands for soliton formation from Gauss beam and the evolution equations in the propagation are obtained. The results show that media loss and longitudinal lattice depth are important factors of formation and stable transmission. Media loss upsets the balance between diffraction and nonlinearity, leading to radiation and thus destroying the condition for the formation of soliton. In order to maintain the soliton propagation one can compensate media loss by use of proper lattice depth. Not only does the numerical simulation reflect the propagation trait of the lattice soliton intuitively, it also confirms results of the analytical treatment once more.