Study On Transmission Characteristics Of Elliptical Cylindrical Hybrid Surface Plasmon Waveguide

With the continuous development of information technology, people have increasingly demanding on optoelectronic integrated degree, but the diffraction limit becomes the bottleneck of high-density optoelectronic integrated circuit development. With the strong light local characteristics and transmission characteristics in the sub-wavelength, hybrid surface plasmon polaritons waveguide can break the diffraction limit, and it is widely applied and researched on the miniaturization and integration of optical device.On the basis of combination with the performance study of many hybrid surface plasmon polariton waveguides, we design the elliptic cylindrical hybrid plasmonic waveguide. And we simulate and analyze it by using the finite element software COMSOL. The contents of this paper are as follows:Firstly, we analyzed and compared the effective mode refractive index, propagation length, mode area and figure of merit of hybrid waveguide under the different ratio and dimension. Based on the trade-off between local characteristics and transmission length of the waveguide, we optimized this waveguide structure. In this way, it can travel over large distance(485 um) with strong mode confinement(range from 2?/ 270 to ?2 / 27). And its transmission loss is effectively reduced. In addition, quality factor curve also confirmed good trade-off between hybrid waveguide.Secondly, we simulated various field distributions of hybrid waveguide in different sizes, using the coupled mode theory to explain them. The mode characteristics between elliptic cylindrical hybrid waveguide and other structure's waveguide are compared, the trade-off of elliptic cylindrical hybrid waveguide is outstanding, and propagation distance and mode size is better than others. Besides, compared to several documents' results, elliptic cylindrical hybrid plasmonic waveguide's propagation length is 50~200 um longer than other documents in the case of approximately equal mode area.At last, we simulated a directional coupler based on elliptic cylindrical hybrid plasmonic waveguide, and analyzed the mode figure, coupling length curve and maximum transfer power. The coupler's coupling length is optimized by changing the distance between the two parallel waveguide. When d is equal to 100 nm, the coupling length is the shortest, with only 1.654 um. By comparing with the couplers based on other waveguide structure, the maximum transfer power of this paper is larger than the ridge nanowires and cylinder structures'. Correspondingly similarly, the coupling efficiency is higher than directional coupler based on the aforementioned waveguide structure.