Theoretical Study On Storage And Retrieval Of Nondestructive Surface Plasmon Polariton Solitons

Electromagnetic induction transparency(EIT)has become one of the important means for people to actively control the optical properties of media since it was discovered in the last century.It can significantly enhance the linear and nonlinear interactions between light and coherent media,making the weak light nonlinear effect possible.In recent years,EIT has important applications in the fields of slowing down of light wave groups,optical storage,optical switching,and optical solitons.Among them,optical storage based on the EIT mechanism has recently become one of the research hotspots in the optical field due to its excellent storage performance and broad application prospects.With the continuous maturity of experimental technology,EIT-based optical storage and reading in systems such as free-space cold atomic gases,hot atomic gases,doped crystal materials,hollowcore photonic crystal fibers,and nanofiber surfaces have been realized and are expected to It will be used in all-optical information processing in the near future.In recent years,the research on Surface Plasmon Polaritons(SPPs)in metal micro-nano structures has gradually developed into an important branch in the field of micro-nano optics.SPPs are collective excitation modes produced by the interaction of incident photons with free electrons on the metal surface.The energy of SPPs can be confined to a spatial scale much smaller than the wavelength of the light wave,which breaks through the diffraction limit of the focused beam and has the characteristics of near-field electric field enhancement.Therefore,SPPs are considered to be one of the most promising carriers for the realization of a new generation of micro-nano integrated photonic devices.With the increasing demand for miniaturization of storage devices,the storage of SPPs in micro-nano waveguides has also attracted the attention of a large number of scientific researchers.However,due to the existence of metal ohmic loss,dispersion,diffraction and other effects in the system,it is difficult to improve the storage efficiency and fidelity of SPPs.In response to the above problems,this article has studied in depth the optical storage and reading of symmetric and antisymmetric SPPs modes in metal-dielectric-metal(MDM)waveguides with the aid of gain.The main research results include:(1)In the Ladder-type three-level cold atom system,the coherent control of the ultra-slow optical soliton is achieved by external incoherent pumping.Based on the semi-classical theory and the singular perturbation method,the MaxwellBloch equation describing the interaction of light and the three-level Laddertype atomic gas in the system is derived first,and the top energy of the threelevel Ladder-type atomic gas is selected as Rydberg state.Then,the multiscale method is used to analytically obtain the solutions of each order.In the linear region,the dispersion relationship and group velocity of the probe light are derived,the slow group velocity propagation of the probe light is realized,and the linearity of the incoherent pump pair system is explored.The influence of properties;in the nonlinear region,the nonlinear Schrodinger equation for detecting the nonlinear propagation of light is derived.By selecting appropriate system parameters,the optical solitons that propagates stably in the transparent window is obtained,and the method of numerical simulation is used to explore The stability and coherent control of the optical solito are discussed.(2)Research on the storage and reading of gain-assisted SPPs in the Laddertype three-level cold atom system in the MDM waveguide.First,starting from Maxwell's equations,the symmetrical and antisymmetric transverse magnetic(TM)mode distributions of the MDM waveguide are derived,and the intrinsic dispersion relationship is obtained.Since the light is tightly bound on the metal surface,the interaction between the light and the atom is extremely polarized.The earth is strengthened,and at the same time,the EIT effect is also strengthened.Comparative studies have found that the symmetrical mode of SPPs has a small ohmic loss,which is a long-range mode but has a small local enhancement factor of light,while the antisymmetric mode has a large ohmic loss,which is a short-range mode but has a large optical local enhancement factor.Based on the semi-classical theory,the Maxwell-Bloch equation describing the dynamic evolution of the system is derived.Due to the non-uniform distribution of the modes,the dispersion of EIT also has the characteristics of non-uniform spatial distribution.We have developed a system to deal with the non-uniform effects in the system.The average field theory of SPPs proves that SPPs solitons can be generated.Based on the EIT mechanism,the high-efficiency and high-fidelity storage and reading of SPPs solitons are realized.At the same time,we are also on how to optimize the storage of SPPs solitons to further improve efficiency and fidelity Theoretical exploration was carried out to study the non-linear effects in the surface utilization system,which can effectively improve the storage efficiency and fidelity of SPPs.The results of the research have important application value in the fields of micro-nano-size optical interconnection and all-optical information processing.The research content of this article is to establish the basic theory and calculation method of the resonance interaction between SPPs and multi-level quantum emitters in the waveguide system,to understand the nonlinear and quantum optical properties of SPPs,and to explore the integration of SPPs in micro-nano-integrated all-optical information processing and The applications in transmission are of more important significance.