Analysisi Of The Focusing Characteristics Of The Vector Field And The Design Of The Light Source

With the development of new technologies such as quantum communication,photon gets more and more attention from the science research or economic production,from health care to the national defense science and technology in contemporary society,the ancient and mysterious physical term is more and more mentioned and playing an increasingly important role,and has become one of the hot topics in the current scientific research.At present,research on vector field has become one of the hot spots in the field of optics,polarized vector field distribution can produce many interesting characteristics,for example: the distribution of radial polarization vector field can be produced more tightly focused energy and light spot formation and distribution of wave field with strong vertical polarized wave;spatial distribution can offer a photon entanglement degree of freedom.So people gradually realize the potential value of vector fields in many fields,such as single molecule imaging,laser micromachining,super-resolution,and so on.Of course,the research of vector light is still in the primary stage of the world,some theoretical and practical problems are still waiting for people to explore.Therefore,in this paper,we explored and simulated the specific vector field theoretically,and developed a Nd:YAG laser which can provide laser light source for vector light.The main contents of this paper are as follows:This paper introduces vector beam and mathematical expression,and then introduces two methods of generating vector beam,active generation and passive generation.The main difference between the two modes of generation is to create a vector beam in a laser resonator.The choice of polarization mode is the main aspect of resonator design.The main choice means can be achieved by birefringence,two color of light or micro structure optical elements.In the way of passive generation,we can use liquid crystal elements,space variant retarders,polarizers and other special optical elements to realize the generation of external vector optical field.The characteristics of the focusing field of different topological charges are analyzed with the radial vector beams with multi vortex phase.By using the Richards-Wolf vector diffraction theory,analyzed the influence of the loading on the number of different topological vector focusing field when vortex is two,three and four.The analysis shows that the change of topological charge affects the distribution of the focused light field.The increase of topological charge will lead to the phenomenon of tight focusing,which is a good theoretical guidance for the regulation of the light field and the utilization of laser energy.The design and development of a Nd:YAG laser which can provide a laser source for the production of vector light is developed,and its performance is optimized.