The Research Of Optical Micro-nano Structures Based On The Metal Grating

Surface plasmon resonance is the coupling between the free electron in the metal and the incident electromagnetic wave.The metal nanomaterial has the advantages such as local electric field enhancement and breaking the traditional diffraction limit because of the effect of the plasmonics,and can be used for the applications such as optical filter,absorber and sensor.The metal nanomaterial device is promising because of the progress of the nanomanufacturing technology.This paper put forward multiple metal nanostructures mainly based on the grating for optical filter,optical absorber and optical sensor respectively.And the optical properties of these structures are mainly analyzed by the finite difference time domain method.The main contents of this paper are listed as follow.(1)Optical filter: the metal nanoslit grating structure and the metal thin film with dielectric grating are both put forward for visible filter.And the metal hole array structure is used for the infrared filter.The properties of the structures are analyzed by changing the parameters such as period.(2)Optical absorber: a structure based on the metal film,dielectric and metal circle particle array and the structure based on the metal film,dielectric and metal hole array are put forward for the narrow band mid-infrared absorption and they are owing to the local surface plasmonic and surface plasmonic polarization respectively.a metal groove structure with multiple depths is presented for wide-angle polarization-insensitive ultraviolet–visible absorber.The metal grooves can enhance optical absorption by the local cavity mode resonance and the resonance wavelength can be tuned by the depth of the groove.(3)Optical sensor: a double non-symmetric metal grating is put forward for the optical sensor.The structure can cause two strong absorption in the near-infrared region owing to the plasmonic effect and local cavity mode respectively.And both absorption peaks have high refractive index sensitivity and large figure of merit.