Effect Of Periodic Structures Of A Vector Light Field And It's Application In Displacement Measurement

Recently,the vector optical field has attracted great interests due to its novel properties and potential applications,and its states of polarization(SoP)distribution is affected by the initial phase distribution,radial modulated parameter,polarization topological charge number.In this paper,we systematically studied the propagation properties of a vector light field after passing through some periodic structures(e.g.single slit,circular hole,grating).The study on the Fraunhofer diffraction of a single slit and a circular hole of a vector light field with different SoP distribution,far-field distribution shows different characteristics.By regulating the radially varying vector optical field of the SoP in the cross-section of the incident light field,the conclusion is drawn that the total interference intensity and the distribution of the two polarization components x and y are regulated respectively by the topological charge m,the initial phase ?0 and the radial regulation parameter l.Through the study on grating diffraction of vector light field with SoP distribution variant along the vertical direction of the grating,the results show that the components of x-,y-and the total complex diffraction fringes in the far field can be obtained by regulating the radially varying polarization vector light field in the cross-section of the incident light field.Sensor of grating displacement measurement system has gradually developed toward the direction of intelligence,and the application field of vector light field is also very extensive,including optical displacement measurement,optical imaging,laser mapping and so on.Because of the vector light field has many unique properties that are different from the scalar light field,a Moiré fringe is generated by the superposition of the strips of the x-and y-polarized components after the vector light field passes through the grating.By using of this characteristic of vector light,a set of displacement measurement system based on vector light field is designed.The vector light field displacement measurement system is applied to the precision displacement digital control detection system to detect the displacement signal on the numerical control machine tool in real time.In this system,hardware structure design,displacement signal processing circuit design,communication serial circuit design,display and key alarm circuit design,and lower computer and upper computer software design were carried out.Finally,a more comprehensive analysis evaluated the advantages and disadvantages of this displacement measurement system.By adjusting the distribution of polarization states of the vector beam,different Moire fringe distributions are generated to increase the sensitivity of the measurement,and the accuracy of the displacement measurement can be improved by the subdivision circuit and directional circuit to process the displacement signal.