Research Of The Hybrid Surface Plasmon Waveguide Based On Metal Grating And Gain Medium

Optoelectronic integration of traditional optical device cannot be realized because of the diffraction limit.Surface plasmon polariton?SPP?can break the diffraction limit and have long been considered by researchers as one of the important ways to realize photonic circuits.However,the problems of surface plasmon waveguides have not been solved,which are large transmission loss,poor mode field limitation,and weak anti-interference ability.In recent years,the hybrid surface plasmon waveguides have been found to have strong field confinement ability and low loss at the sub-wavelength scale,making it widely concerned and studied in engineering,nanophotonics,biomedical and other interdisciplinary disciplines.In this paper,metal grating and gain medium are applied to mixed surface plasmon waveguides.And two different new hybrid surface plasmon waveguide structures are designed.The characteristics of these structures based on the finite element software are analysised,and the designed waveguide structure has low loss and strong coupling characteristics are consluded.The contents of this article are as follows:?1?The research status and application prospects of hybrid surface plasmon waveguide are introduced,the dispersion models and excitation methods of surface plasmon polaritons are analyzed and the principle of simulation algorithm-finite element method is emphatically expounded.?2?A mixed plasma waveguide based on metal grating structure is studied.Firstly,the basic model properties of the waveguide structure with different geometrical dimensions are analyzed,including electric field distribution,transmission length,mode area,quality factor and so on.Then the influence of geometric parameters on the characteristics of the waveguide structure is explored,and the optimal size is obtained:the thickness of the grating is 150 nm,the thickness of the lithium niobate is389 nm and the grating width is 42 nm.Under the above conditions,the normalized mode field area is 0.0334,and the transmission loss is 0.0004 cm^-1,so the transmission loss is minimized while maintaining the sub-wavelength field limiting capability.The studied waveguide'transmission loss that is less than 3 orders of magnitude compared with the similar structures,therefore the waveguide have a good balance between field limiting ability and transmission loss.?3?A hybrid plasmon waveguide based on symmetric cylindrical nanowires is studied,the transmission characteristics of the nanowire waveguide are analyzed,and the mode characteristics and optimal parameters are obtained under different sizes.Compared with similar structures,although the transmission loss is in the same magnitude,the structure of the optimal size,which shows a stronger coupling effect and stronger light confinement capability.Based on the above results,the laser characteristics of the waveguide are finally studied and the corresponding nano lasers are obtained with low threshold is.1 1?10⁶m^-1.The research results provide a certain theoretical basis and design ideas for the manufacture of micro-nano optoelectronic integrated devices on a new generation,and providing a reference for the development of micro-nano photonic integrated technology.