Research On Flexible Transparent Terahertz Metamaterial Absorbers

Metamaterial absorbers are artificially designed by sub-wavelength structures,which have the advantages of high absorption,wide absorption bandwidth,thin structure thickness and so on.Broadband terahertz absorbers have important applications in terahertz modulation,imaging,and communication.This paper focuses on the design and fabrication of the flexible and transparent broadband terahertz metamaterial absorbers.The main work is as follows:1?The broadband terahertz absorbers are usually designed by complex nesting or stacking resonant structures.An optically transparent broadband terahertz metamaterial absorber based on circular sector was designed.The absorber demonstrates over 80%broadband absorption in a wide frequency range of 0.4THz-1.04 THz,which reaches 88.9%of the central frequency.The thickness of the absorber is only 1/15 of the wavelength to the lowest absorption frequency.Samples were fabricated by photolithography,and the absorption and optical transmittance of the absorber were experimentally verified using a terahertz time-domain spectrometer and an ultraviolet spectrophotometer.The experimental results verify the accuracy of the design.2?Based on the transmission line theory and impedance matching theory,a flexible and transparent broadband terahertz absorber is designed by using an inductor grid network structure.The absorber has an absorption efficiency of more than 90% in the range of0.098THz-0.353 THz.The full-wave simulation results show that the absorber is insensitive to the polarization of the incident wave and has good incident angle stability.Samples were fabricated by Electrohydrodynamics-printing technology and tested by the terahertz timedomain spectrometer.The experimental results fully verified the circuit simulation results and full-wave simulation results.