Vector Manipulation Of Optical Field In A PT Symmetry Material

Since the concept of parity-time(PT)symmetry in quantum mechanics was introduced into the field of optics,it has attracted widespread attention.In particular,it is found that the PT symmetric optical system with gain loss can bring about a series of novel phenomena,and after more than ten years of development,PT symmetry has been applied to various optical devices.Because of the great potential value of PT symmetry in scientific research,research related to PT symmetry has important significance.The interaction between optical field and matter has always attracted much attention,but a large number of studies have focused on the scalar optical field with uniform states of polarization.The vector optical field has a unique polarization distribution structure that is different from the scalar optical field,So the interaction of vector optical field and matter can lead to more novel optical phenomena and effects.Therefore,the manipulation of complex structure vector optical field of related new materials has attracted great attention,especially the manipulation of vector optical field in PT symmetrical materials.At present,the interaction between the beam and the PT symmetric optical system still needs more in-depth exploration in related applications.while continuing to explore its novel optical phenomena and the control of vector.This paper mainly explores the manipulation of vector optical field in PT symmetrical materials,and the main contents are as follows:1.Based on the coupled linear Schr(?)dinger equation(LSE),the propagation dynamics of a vector optical field(VOF)with helical phase and azimuth changing polarization distribution in a PT symmetric optical system is studied.The evolution of the Stokes parameter of the VOF with azimuth various polarization in the PT symmetric optical system is solved by the split-step finite difference method.The numerical results show that in the PT symmetric optical system,the conversion of linear-circular polarization at the periphery of the VOF is due to the coherent superposition of two orthogonal polarizations components,and the influence of changing the gain/loss parameter,refractive index and optical lattice period on the state of polarization of VOF are explored.At the same time,the evolution of the vector optical field in the PT symmetric optical system under the broken condition is also discussed.2.Based on coupling LSE,the evolution characteristics of the optical angular momentum of the vector vortex optical field(VVOF)with azimuthally polarization distributions and helical phase in a PT symmetric optical system are explored.The evolution process of the optical angular momentum of the VVOF in the PT symmetric optical system is solved by the split-step finite difference method.The numerical simulation results illustrate the influence of the parameters of vortex topological charge,polarization topological charge、gain/loss parameter and optical lattice period、and refractive index on the orbital angular momentum and spin angular momentum of the VVOF in the PT symmetric optical system.3.A simple and practical device is designed based on the evolution of the vector beam with radial polarization changes in strong non-local nonlinear media.The device is that uses the vector beam to interact with the medium to realize the conversion of linear polarization into circular polarization.In this device,just by changing the input power of the input beam or changing the transmission distance of the beam in this specific medium,the obtained circularly polarized light can be randomly switched between the three states.