The Polarization Characteristics And Radiation Force Of Laser Beam

Vortex beam becomes more and more popular recently. And researchers have made enormous progress both in theory and application. Vortex beam is applied to he field of laser optics, information and communications, micromanipulation, nonlinear optics, atomic waveguide, microbiology, biomedicine, atom optics, genetics and molecular optical application.This paper aims to explore the characteristics and applications of the partially coherent anomalous vortex beams. Including the theoretical derivation, the establishment of a partially coherent vortex light beam transmission model, the far field characteristics of anomalous vortex beams, as well as the establishment of the radiation force model which can be used to capture particles. The key points are as follows:1. Theoretical derivation make the establishment of a partially coherent vortex light beam transmission model, and explore the far-field characteristics of it, including the intensity and degree of polarization. We can control the topological charge, the coherence length and beam order to control light intensity, and the degree of polarization can also be controlled through the above parameters. To sum up, through the analysis, we offer the guidance of the coherent anomalous vortex beam intensity distribution, and the degree of polarization distribution.2. We explore the polarization properties of the partially coherent vortex beam while passing the ABCD system. Based on the unified theory of coherence and polarization, we study the propagation characteristics of partially coherent anomalous vortex beam in ABCD optical systems. ABCD optical system can be transformed into a variety of optical system according to the needs of specific, such as thin lens optical system which is the most popular one. Therefore, the derivation is more universal and applicable, which lays the foundation for the further study of the characteristics of the partially coherent anomalous vortex beams in various optical systems. On the basis of this, we explore the polarization properties of partially coherent anomalous vortex beams through a thin lens optical system, including the intensity and the degree of polarization. By controlling the topological charge, coherence length, the beam order, the source plane intensity, we can control the light intensity distribution and the degree of polarization distribution. Calculation results can help control partitial coherent anomalous vortex beam intensity distribution, and the degree of polarization distribution. It also can help the radiation force.3. Theoretical derivation, make the establishment of a focused partially coherent vortex light beam transmission model after passing through the thin lens optical system, and explore the characteristics of it in the focal plane, including intensity, radiation and scattering power. We can control the distribution of light intensity through the topological charge, the coherence length and beam order. which may make sense to control the intensity distribution of focused partially coherent vortex light beam. And through the research and comparison of transverse and longitudinal gradient and scattering forces. It is found that the gradient force is much larger than the scattering force, so AVB can be used to form three-dimensional potential as an optical tweezers to trap the Rayleigh particles. We can change the number of the topology of charge, coherence length, beam order, etc. to achieve a better trapping effect.