Material fingerprint characteristics of electromagnetic scattering characteristics in terahertz band

The dielectric constant of alpha alumina was calculated using first principles calculations based on intelligent algorithms. RCS of alpha alumina with diameters ranging from 1 to 0.01 μ m was obtained based on Mie scattering of small balls at 300K. Verified by Fourier transform time-domain spectroscopy measurement, the theoretical results of dielectric constant are in good agreement with experimental results, proving the accuracy of material parameter calculation. The characteristic peak positions of the RCS of alpha alumina with a diameter of 1 μ m in the range of 8-35 THz are basically consistent with the intrinsic vibration frequency of the material, indicating that the fingerprint characteristics of the material are helpful for identifying and distinguishing floating objects in the air.