Research On The Regulation Of Bottle Beam And Its Optical Field Characteristics

The technology of optical tweezers is an important tool for trapping and manipulating micro particles.One of its basic properties is that light has momentum.The technology of optical tweezers has the advantage of precise manipulation,which can achieve the purpose of noninvasive manipulation of biological samples,so it has become a research hotspot.In exploring a new technology of optical tweezers,researchers have found a special light field mode-bottle beam.The definition of bottle beam is that there is a three-dimensional closed space with very small or even zero light intensity in toward beam propagation,which is like a special closed container.The bottle beam has the physical characteristics of barrel light intensity distribution and small size of dark spot,which makes it have a very broad application prospect in optical tweezers and laser cooling.Therefore,how to get the bottle beam and analyze its characteristics has become a hot topic in recent years.In the paper,the methods reported about the bottle beam are investigated and analyzed.By designing a more simple and efficient shaping system,and using the software of MATLAB and ZEMAX to control the various properties of the bottle beam,the practicability and diversity of the bottle beam can be further improved.It mainly divided the research work of this paper into the following aspects:(1)A system for generating multiple optical traps of the bottle beam is designed.Based on the theory of diffraction integral and matrix optics,the relationship between the position of multiple optical traps and the deflection angle of the mirror is studied.By adjusting the deflection angle of the mirror,the position of the optical trap can be changed arbitrarily to achieve the purpose of stable trapping particles.(2)It produces the elliptical Gaussian beam by using the circular aperture which is rotated around the axis.The optical system of the elliptic Gaussian beams with different long and short axis is designed to form a bottle beam by focusing through the axicon lens system.The bottle beam carries different sizes of notches.The relationship between the rotation angle of the circular aperture and the notch size of the bottle beam is studied by adjusting the distribution of the light field in the system.This method can open and close the optical trap freely,which provides a technical means for the capture of particles.(3)Gaussian beams are shaped by polygonal apertures(including regular triangular,regular quadrilateral and regular hexagonal apertures).And the shaped beam is adjusted to enter the axicon lens system to generate a bottle beam with a notch.The characteristics of the central diffraction spot and the beam morphology of the bottle beam are analyzed,and the influence of the number and position of the edges of the polygonal aperture on the notch in the bottle beam is studied.It lays a foundation for the multi-field application research of bottle beams.