Research On The Generation Technology Of Optical Vortex Array

Optical vortex is a special light field with a helical wavefront and centeral dark hollow structure, which can generate very strong binding force on the particles that are captured. Therefore, it is an important way to achieve optical tweezers now. In recent years, the optical vortex has been widely used in the optical micromanipulation, information communication, etc. Optical vortex array, which can operate many particles simultaneously and efficiently, gained considerable attractions recently.In this paper,the related problems of generating vortex array by wedge diffraction was studied theoretically and experimentally, the main research work is as follows.1. An optical vortex array generation method was proposed based on the study of the generation of single optical vortex by the diffraction of optical wedge. The rectangular optical wedge array was adopted in the proposed method. If the spacing between adjacent beams in the longitudinal direction is equal to the integral multiple of beam diameter, the beam array irradiation on the rectangular optical wedge array will produce vortex array. The optical simulation was implemented to verify its feasibility.2.The optical design and fabrication method of the optical wedge array were studied. The reasonable structure and processing method of the wedge array were designed. And the wedge array was fabricated practically. Then the experimental system generating optical vortex array was designed. And the experimental system was established, in which the spatial light modulator was used to generate the desired beam array by Dammam grating.3.The experimental research was conducted to generate vortex array by the optical wedge diffraction. The influence of the optical wedge parameters on the single cloumn of vortexs was studied experimently. The regulation of basic unit of Dammam grating on beam array are researched in order to solve the problem of matching the beam array and wedge array. The beam array with adjustable structure was obtained finally.The optical vortex array was generated successfully. The experimental and the simulative results have good agreement, which proved that the optical wedge array can generate vortex array effectively.