Metal-Coated Silicon Nanowire Embedded Plasmonic Photonic Crystal Fiber: Kerr Nonlinearity and Two-Photon Absorption

In silicon, the presence of two photon absorption (TPA) and the generated free carriers can strongly perturb any Kerr-related nonlinear performance. Special consideration about the geometry and applied input power is needed to reduce undesirable free carrier effects (FCE). In our study, a plasmonic photonic crystal structure consisting of a central metal-coated silicon nanowire is proposed. The photonic crystal cladding and plasmonic nature of the guided modes provide the efficient wave propagation in the subwavelength core radius size of 150 nm, well beyond the diffraction limit at λ = 1.55 μm. Considerable increase of the threshold powers (approximate increment of 42dBW and 12dBW for the free carrier absorption and dispersion threshold powers at rSi = 500 nm) for the observation of FCE is a distinguished feature of the proposed structure which guarantee the safe launch of high input powers for full development of Kerr-based phenomena. An excellent agreement between the numerical solution of the nonlinear schrodinger equation and the calculated threshold powers confirms the obtained results. The proposed structure has potential applications in the areas regarding the Kerr-related nonlinear performance especially with relative high powers utility.