Optical Field Focusing With Illumination By Metal Plasmonic Waveguide Coupling

With the rapid development of optoelectronics and nanotechnology,the requirements of integrated optics on the density of integrated systems are gradually increasing.The traditional lens is difficult to achieve more compact focusing and the flexibility of the adjustment of the focal field is low,so the research hotspot has turned to the field of microstructure.Optical waveguides based on surface plasmon polarizers greatly reduce the size of photonic components,break the limits of optical diffraction,and obtain sub-wavelength-scale focused spots.This has broad applications and attracted the interest of researchers in various countries.In this paper,focusing devices based on several kinds of metal plasmonic waveguides are studied,and the interaction between electromagnetic waves of different polarization states and metal-insulator-metal(MIM)optical waveguides is studied.The distribution of polarization along the beam cross section is uniform can be divided into the vector beam and the scalar beam.First of all,focusing devices based on plasmonic waveguide,such as wedge-shaped inclined-slot long-focal-depth plasmonic lens and radial-polarized long-focal plane plasmonic lens of silver thin film,are introduced firstly,and then A side-illuminated plasmonic planar lens is studied,which of the coupling illumination from free space illumination to highly integrated illumination is analyzed and the structure and the groove are adjusted to achieve the final control effect.Secondly,the mode analysis of cylindrical plasmon waveguide is studied.A compact and low-loss cylindrical hybrid plasmon waveguide is obtained,which not only can achieve a strong mode field limiting capability,but also can maintain the characteristics of low-loss long-distance transmission.Aiming at the effect of SPP excited by a waveguide with dielectric-metal double-layer conical structure under the condition of radial polarized light source illumination,a focusing device based on a hybrid plasmon waveguide is proposed in this paper,a three-layer cylindrical symmetry conical structure is used instead of the original two-layer structure,a field enhancement device for surface ring groove formation is proposed in this paper.The structure of the field enhancement device can be applied in ultra-high density integrated optical path,which is of great significance to the realization of the design and integration of nano-photonic devices,the processing of new light sources,communication optical fibers and the detection of micro-nano sensors.