Characteristics Research Of The Hybrid Surface Plasmonic Waveguides For Ultraviolit Nanolasers Applications

With the development of Photonic integrated devices,surface plasmons have attracted considerable attention in the field of nano-photonic technology.Surface plasmons polaritons(SPPs)are electromagnetic surface waves propagating in the interface of two medium whose relative dielectric constant symbol is contrary.Its character of surface wave make the energy tightly confined at the metal-dielectric interfaces.At the same time,it is far smaller than the wavelength of the free space in the space dimension,which is no longer restricted to the diffraction limit.And the characteristics of surface plasmon waveguide is different from the traditional optical waveguide.The plasmonic waveguide can break through the diffraction limit and realize subwavelength limit.In many types of plasmonic waveguide,hybrid plasmonic waveguides have strong ability of light field limit and low propagation loss,reflecting its unique advantages.In addition,the current research work is mostly in the infrared and visible light wave band.However,the hybride plasmonic waveguides under the ultraviolet band have more extensive application prospects,such as optical communication,biomedicine and so on.In this paper,based on surface plasmons and surface plasmon waveguides theory,a new kind of hybrid plasmonic waveguide structure with a metal ridge is designed under the ultraviolet wavelength(working wavelength of 390 nm),and its properties were studied by using the finite element method.The structure is applied to nanolasers,and the electric field distribution and characteristic parameters were studied.The structure provides the technical support for the miniaturization and integration of nanometer devices,and has broad application in biomedical,optical communications and other fields.The main work of this paper is as follows:(1)The basic theories about surface plasmons and surface plasmonic waveguides are introduced,the characteristics and advantages of hybrid plasmonic waveguides are mainly analyzed.(2)The paper proposed a new hybrid plasmonic waveguide with a semicircle metal ridge and the same shape magnesium fluoride layer.The paper studied the the radius of themetal ridge,the thickness of the magnesium fluoride layer and the radius of the nanowire on the impact of the fundamental mode of the waveguide,and analyzed the electric field distribution,modal characteristics,propagation length,and the quality factor.Results show that we can obtain low propagation loss and ultra-deep-subwavelength limit ability by optimizing the geometric parameters of the structure.(3)Applied the designed hybrid plasmonic waveguide to nanolasers,and studied the related features.The magnifying principle of the SPPs because of the gain medium are proposed,and also introduced some materials used as gain medium.Then,three dimensional mathematical model was built in the COMSOL Multipgysics software platform,the electric field distribution of the nanolaser,gain threshold and quality factor were studied.Results showed that the nanolaser has low gain threshold and large quality factor while the waveguide has good comprehensive properties.This indicates that the nanolaser has strong limit ability of microcavity properties while maintaining the low gain threshold.In this paper,the characteristics of the structure is good,and it can be applied to nanolasers,it is potential to lead to the miniaturization and integration of photonic devices,and has wide application prospects in biology,medicine and optical communications and so on.