Fabrication Of Optical Fiber Microcavity And Its Optical Manipulation Characteristics

Since the late 1960s,after the groundbreaking research on optical manipulation by Ashkin of Bell Labs in the United States,the technology of optical manipulation and optical capture have developed rapidly.The optical tweezers use optical potential wells to capture and manipulate the particles,-and it has the characteristics of non-contact and lossless.The fiber optical tweezers has the advantages of lightness,flexibility and low cost.In recent decades,domestic and foreign scientists have conducted a lot of research oin optical manipulation and optical capture.The application of fiber optical tweezers have been extended to the field of measurement,biology,medical research.In this thesis,an optical fiber tweezer with a microcavity structure is proposed,and its acquisition characteristics are systematically studied using simulation software based on finite different time domain method.The simulation results show that after filling the licrocavity with water and transparent ultraviolet glue,the light is strengthened due to the interference of light,and the particles of SiO2 with a diameter of 3 μm can be captured at the convergence point.On this basis,the relationship between the capture characteristics of this structure and the refractive index and filling amount of the filler material was studied.The optical fiber tweezers has a large diameter and a structural knot.The advantages of being practical and not easy to break,is suitable for the field of life sciences.A structure of the outer coating of the cavity was designed and fabricated on the fiber.The capture characteristics of the structure were calculated and analyzed by finite different time domain method,and the large-scale capture of the particles by the structure was verified by experiments.The experimental results show that the structure can capture polystyrene particles by photophoretic force,and manipulate a wide range of silica particles.As the optical power increases,the handling efficiency of the particles can be improved.Due to the inconsistent movement of the two particles,the sorting of the particles is achieved by this structure.The coated microstructured fiber not only simplifies the complex optical path,but also can be reused many times,so it can reduce costs and be more practical.