Research On Polarization Splitter Based On Phase Transformation

Metamaterials is a kind of artificially microstructured materials with exoticmaterial properties that are not found in the nature. The electromagnetic properties ofmetamaterials can be tuned at will and they have brought unprecedented applications,such as invisibility cloaks and superlens with a resolution beyond the diffraction limit.Metamaterials has been a hotspot in recent ten years, and especially under thecoordinate transformation theory guidelines numerous novel photonic devices havebeen proposed and realized. Metamaterials designed on the basis of transformationoptics, also called transformation media, can be used to flexibly control and guide theelectromagnetic wave transmission.In this paper, we design the polarization splitter using metamaterials based ontransformations optics. The specific work we carry out is as follows:First, we study polarization wave deflection using transformation media. Areverse transform method of phase transformation,that is inverse transformationmethod, which develops form direct transform method can achieve the same effect.We establish the coordinate transformation of polarization wave TE wave and TMwave deflection and obtain the permittivity and permeability tensors of themetamterials. The angle of TE wave and TM wave can be manipulated neatly. And thegood performance of the beam modulation is verified through full wave numericalsimulations based on the finite element method.Second, we study the design of polarization splitter with the exit directioncontrollable using transformation media. The inverse transformation method of phasetransformation can realize arbitrary phase transformation with no irregular shapes. Wecan realize the splitter of mixed wave TE wave and TM wave using transformationoptics based on the polarization wave. We set the deflection angles of mamiputing theTE wave and TM wave in the transformation media to realize the anticlockwisedeflection of TE wave, and the clockwise deflection of TM wave, then thepolarization splitter with the exit direction controllable can be obtained. The designeddevices are validated by full wave simulations.Third, we study the design of polarization splitter with the exit wavefrontcontrollable using transformation media. We can manipulate the exit wavefront usingthe transformation optics. The normal incidence wave can deflect using transformation media. The deflecting angles of exit wave can be controlled flexiblely.We also can convert planar wavefront to a curve one. Polarization splitter with theexit wavefront controllable has the function of focusing. Numerical simulations aregiven to validate the performance of the theoretical design.