THz hooks generated on the basis of hollow reflection mirror

Abstract

THz hook (TH) is a curved beam in THz frequency region, which is characterized additionally by the bending angle θ besides focal length, intensity and transverse size. Here, we study paired THs generated by two cuboid scatterers placed on a hollow mirror. The study focuses on the effects of hollow geometry and polarization state of incident wave on the THs performance. The results show that the hollow geometry affects mainly the bending angle θ, which can change by two fold. The effect is associated with the hollow geometry induced changes of number and position of phase singularity in Poynting vector distribution. The polarization state of incident wave affects considerably both bending angle and focal length. As the polarization state is changed, the FL (focal length) can change by ∼26 fold and the θ by ∼9° due to the interactions of the polarized electric field with scatterers and with the hollow mirror. It implies that the use of hollow mirror results in significant enhancement of polarization effect on the TH performance. Present study allows to conclude that the bending angle and focal length of paired THs generated on the basis of the hollow mirror can be efficiently tailored by the hollow geometry and polarization state.