GO/PO Method for the Terahertz Scattering Computation of Objects With Multiple Small-Scale Grooves

In this paper, the Geometric Optics (GO)/Physical Optics (PO) method is improved to analyze the terahertz (THz)-wave scattering characteristics of objects with multiple small-scale grooves, where the grooves are of the same size. For the traditional GO/PO method, when the number of grooves reaches dozens or even hundreds, the existence of a large number of redundant intersection tests will be a main limitation to calculate the electromagnetic (EM) scattering in THz band. Therefore, in order to solve this problem, the scattered field from one of the grooves is computed using the GO/PO method and extended to obtain the scattered field of the other grooves according to their dimensional information. In this way, the computation load is effectively reduced. To demonstrate the validity of our method, the results are compared with those of MLFMM, traditional GO/PO method and experimental data. A good agreement is achieved. Meanwhile, the runtime of our method is compared with that of traditional GO/PO method, where the computational time is greatly saved. Furthermore, the scattering characteristics of objects with multiple small-scale grooves in THz band is studied. The simulation results show that the small-scale grooves will have a great effect on EM scattering characteristics in THz band.