Research On Phase Modulation Polarization Splitting Based On Artificial Microstructures Of Terahertz Wave

In terahertz,due to the lack of suitable natural birefringent materials,and the inherent high material loss,it is still difficult to achieve polarimetric devices with polarization properties of the incident wave Splitting.However,this ability can be achieved well by using the beam control capability of the reflector,and the desired angle radiation can be achieved when the reflective array does not need a complex feed network.The combination of a reflective array and a polarization grating can more flexibly control beamforming and polarization control.With the development of integrated circuit lithography,reflection array applications have been developed into infrared or even visible light.This paper first introduces the background and status quo of polarization separation.After the introduction part,the core part of the paper shows the theoretical basis of polarization separation,and focuses on the theoretical basis of the reflection array,and the principle of grating isolation.The purpose is to use a variety of phase control,realistic TE(electrical field polarized wave in the y direction)and TM(electrical field polarized wave in the x direction)are polarized in different phases and phases,so that different arrangements of the TE polarization and the TM polarization realize polarization separation of different reflections.Thesis mainly includes:Study the radiation characteristics of a terahertz reflective array,which consists of a resonant microstrip open rectangular structure on the dielectric substrate,between 0.3-0.42 THz,phase modulation of one of the polarized waves,and analysis of a rectangular metal opening The relationship between the size and phase of the ring and the effect of different variables on the reflection phase.Then,the subarray is designed according to the progressive and cyclic phase distributions to deflect the incident beam to a pre-designed angle.And by replacing the backplane with a grating,it has the advantages of a reflective array and a grating at the same time,the TE wave polarization is deflected to the desired direction,and the TM wave is transmitted through the entire array structure.The characteristics of arrays with orthogonal I-shaped structural elements and different modes are studied,and the influence of different variables on different polarization phases is analyzed between 0.3-0.4 THz,and the direction parallel to the electric field and dipoles are obtained.The phase change is very large,and the vertical variation is small.Then,multiple variables are used to optimize the phase curve within the frequency range so that two different polarization smoothing phase curves are obtained between 0.3-0.4 THz.And the use of different polarization of the phase arrangement,so that in different angles and different directions of the two phase arrangement,polarization beam splitting purposes.