Poincare Sphere Vector Light Field Based On Sphere Center Projection Desig

With the birth of laser technology,our optical research has become more flourishing,how to apply laser technology to many other fields,becomes extremely important.In order to explore the properties and applications of laser technology more deeply,it becomes more and more important to regulate the optical field.The degree of freedom of the optical field is mainly divided into four kinds,including frequency,amplitude,phase and polarization state.Among them,the research on frequency,amplitude and phase regulation of optical field has been more in-depth and has been widely used in various fields.The control of the polarization state of the optical field is generally realized by adjusting the spatial distribution of the polarization state of the optical field,which can generate the vector optical field with non-uniform distribution of the polarization state.Compared with the scalar optical field,vector optical field is different in that the polarization distribution of scalar optical field is the same at different places in space,while the polarization distribution of vector optical field is different.Therefore,the control of vector optical field is more rich and more complex,and its properties are more unique and diverse.It is widely used in the field of optical capture,optical micromachining,and optical micromanipulation.Poincaré sphere is a model used to represent polarization states,each point on the sphere has a unique polarization state corresponding to it.By superposition of different orthogonal polarization states on the Poincaré sphere,some new vector optical fields can be obtained,such as full Poincaré sphere vector optical field,generalized Poincaré sphere,and hybrid order Poincaré sphere vector optical field,etc.In this paper,a new type of Poincaré sphere vector optical field is proposed by combining sphere-centric projection with the Poincarésphere.The main contents of this paper are as follows:1.This paper introduces a new vector optical field by taking out the polarization states in the complete sphere of the Poincaré sphere by using spheroidal projection.By changing the size of the topological load and changing the value range of the projection,the change rate of the long-axis orientation of the polarization state in the new vector field is controlled.The vector optical field is generated by theoretical simulation and experiment,and its polarization distribution is analyzed.This new Poincaré sphere vector optical field enriches the types of vector optical fields to a certain extent and provides a new idea for the generation of the new Poincaré sphere vector optical field.2.The new Poincaré spherical vector optical field obtained by the centroid projection will be used for tight focusing to obtain the corresponding focal field.In this paper,the intensity distribution,Stokes parameter,spin angular momentum,energy flux density distribution,and energy flux direction of each focal field under different conditions are simulated.On this basis,Richards-Wolf vector diffraction theory is used to analyze each result,which provides a theoretical basis for the application of this new vector optical field.3.Based on the method of sphere-centric projection,the vector optical field of any latitude and longitude ring range or sector range on the Poincaré sphere is extracted by adjusting different parameters.By comparing the vector optical field obtained under different parameters and methods,it is found that there is more than one way to generate the same vector optical field,and the parameters are not only fixed values,which enriches the idea of generating vector optical field.