Research On Multiwavelength Dispersion Characteristics Of Optical Metasurfaces

Optical dispersion has always been a very valuable part of the optical field,and it plays an important role in optical information processing and spectral analysis.The conventional optical devices achieve wavefront modulation of the beam by accumulating a continuous phase delay generated by the beam passing through the component,which mainly depends on the nature or shape profile of the material itself,and is limited by the nature of the natural material.Therefore,the conventional optical devices usually have problems such as large size and difficulty in integration,and cannot meet the application requirements of miniaturization and integration.In recent years,the metasurface has received widespread attention due to its powerful light field control capability.It is a subwavelength artificial layered material.which can be reigarded as a two-dimensional correspondence of the metamaterial.Compared with metamaterial,metasurface has the advantages of easier preparation and smaller loss.Metasurface has the extraordinary physical properties that natural materials do not have.It can realize the flexibility of various characteristics such as electromagnetic wave phase,amplitude and polarization by sub-wavelength microstructure.Regulation.,Its appearance provides a new research idea for people to control the light field.Compared with traditional optical components,metasurface has the advantages of lightness,easy integration,low loss.etc.,and has a very wide application prospect in the fields of optical communication,optical sensing,focusing and imagine devices.In this paper,we focus on the mufti-wavelength dispersion characteristics of metasurface,and explore the application of high-efficiency spectral splitting in the near-infrared band(1450nm-1650nm).The main contents are as follows:1.Aiming at the existing problems of traditional optical dispersion elements,according to the general Snell's law and metasurface working principle.We designed a multi-wavelength dispersion metasurface based on V-shaped antennas working in the near-infr-ared band(1450nm-1650nm).We used FDTD Solutions to carry out simulation test and result analysis on the designed metasurface,which proved its spectral splitting ability in a specific band.And in order to improve work efficiency.we conducted several optimization experiments in different directions and analyzed the test results.2.According to the problem of multi-wavelength dispersion metasurface based on V-shaped antennas.we designed a simpler multi-wavelength dispersion metasurface based on trapezoidal antennas.Compared with the metasurface based on the V-shaped antenna.the antenna array constituting the trapezoidal metasurface contains only one antenna unit per cycle unit,the period length is shortened,the dispersion angle difference of incident light of different wavelengths is increased,and the structure is simpler and easier to prepare.The metasurface adopts the structure of antenna-insulator-metal film.We have proved through simulation experiments that the metasurface can achieve more efficient spectral splitting in the near-infrared band(1450nm-1650nm).