| Surface plasmons(SPs)can effectively solve the diffraction limit problem of traditional optical devices,thereby meeting the development needs of further miniaturization and integration of devices,and are widely used in new subwavelength photonic devices such as sensors,filters,absorbers,optical delay devices and so on,which have greatly promoted the development of highly integrated optical circuits.This paper focuses on the nano wavelength sensors,filters,and metamaterial absorbers of new optical devices in the post-Moore era.Based on the structures of MetalInsulator-Metal(MIM)and metamaterials,specific spectra are designed and device applications are carried out to solve the problems in the device application such as weak controllability,small scope of application,and insufficient performance.The research content and main innovations of this paper include:Based on the side-coupled resonant cavity and the MIM waveguide structure,a variety of multi-Fano resonance systems are proposed and used in the refractive index sensor to solve the problems of single detection point and low accuracy of the single Fano resonance system sensor.The generation mechanism of different Fano resonances in the transmission spectrum was explored in detail by multi-mode coupling mode theory and other methods.A tunable ultra-broadband U-shaped band-stop filter is proposed.The device forms multiple Fabry-Perot cavities between its structural units and periods through the periodic arrangement of bilateral trapezoidal resonators.The superimposed coupling between modes forms an ultrawide U-shaped stopband.The research results show that the filter has a perfect stopband width of 330 nm and can achieve filtering effects in different frequency bands by adjusting the structural parameters.3.The ultra-broadband perfect absorber is realized by constructing a four-layer ladder structure based on the phase change material vanadium dioxide and metal thin film,which solves the problems of complex structure and narrow absorption bandwidth of the perfect absorber.The absorption bandwidth of the absorber over 90%in the dielectric state can reach 6308 nm,and the absorption bandwidth over 90%in the metallic state is 6478 nm.The structure also has the characteristics of temperature insensitivity and polarization independence.4.Two all-dielectric metasurface sensing structures are proposed to solve the problems of low Q value and high fabrication costs caused by a high ohmic loss in metal waveguide sensing structures.A Si cuboid metasurface structure composed of asymmetric semicircular holes was designed by the symmetry breaking method,and the maximum sensitivity of the refractive index sensor was 300 nm/RIU and the maximum figure of merit(FOM)was 440.The permittivity-asymmetric metasurface structure realizes the dual-band polarization-insensitive toroidal dipole quasi-bound states in the continuum with a maximum figure of merit of 910.The proposed devices will play an important role in the fields of optical sensing,optical filtering,metamaterial absorption,photoelectric detection,and so on,which provides a new idea for the realization of new subwavelength photonic devices and lays a solid foundation for the development of highly integrated photonic circuits. |
