Research On The Design And Control Technology Of Three-dimensional Vector Light Field

The vortex beams(VBs)have a helical wavefront structure and a central phase singularity,which cause a hollow distribution of light intensity.Due to the outstanding characteristics of VBs which carry orbital angular momentum(OAM),adjustable VBs have produced huge advanced applications,such as optical tweezers,optical communications,and nonlinear optics.The proposal of the perfect vector vortex beams(PVVBs),one having ring diameter independent of topological charge,further broadens the application of VBs,benefiting from their adjustable light polarization.These new vector optical fields have not only provided new degree of manipulation freedom,but also overcome the limitation of traditional optical vortex.The multiplexing and control of PVVBs in three-dimensional(3D)have opened up new directions for researchers.This type of technology has also been used in the capture and transport of multiple particles,optical imaging and so on.Therefore,the exploration of new PVVBs with three-dimensional characteristics has become a very interesting subject in the field of optics.This thesis mainly studies the multiplexing and shaping of 3D perfect vector light fields and the innovation of this work is summarized as follows:A method of generating multiple perfect vector vortex beams with controllable positions,topological charges and amplitude in three-dimensional space is studied.With the help of the conversion principle of the coordinate system,the shape of the vortex beam is changed from circle to ellipse.The dynamic phase mask used to generate the perfect vortex beams and the corresponding coding method are analyzed.By multiplexing multiple phase mask patterns,more scalar elliptical perfect vortex beams in multi-planes are obtained in simulations and experiments.By the use of the geometric phase element q-plate,the transformation of scalar perfect vortex beams to vector perfect vortex beams is realized.Therefore,the polarization modulation of the perfect vector vortex light fields in three-dimensional space is achieved.A technique of generating and multiplexing multiple vector curve beams based on spatial light modulator is studied to realize the three-dimensional regulation of these beams.The amplitude,phase non-uniformity,and polarization of each curve can be controlled simultaneously.Meanwhile,the size of the curve beam is independent of the topological charge.By introducing the curve expressions and the tunable parameters,we can control the trajectory and position of each curve in the threedimensional space.The complex amplitude of the incident plane is encoded based on an improved iterative algorithm,which realizes the multiplexing of multiple curve beams.Based on the vector beam synthesis system,polarization modulation is performed on curve beams multiplexed in multiple discrete planes.These vector geometry curve beams are expected to be useful for the trapping of micron-sized dielectric particles and may open up new perspectives for the transport of particles along programmed trajectories.A method of simultaneously shaping multiple three-dimensional vector curve beams is proposed,which realizes the continuous variation of polarization state along arbitrary prescribed trajectories.The scheme is based on the coaxial superposition of the orthogonally polarized 3D base vector curve beams through non-iterative holographic 3D beam shaping technique.In particular,the hybrid 3D vector curve beams array is also generated with identical depth range.The transversal position of each vector beam can be governed independently by introducing the transversal phase shift factors.Moreover,the multiplexing of 3D vector beams is realized with different depth ranges in the focal region along the beam propagation by introducing the axial phase shift factors.Each 3D vector curve beam can be regulated independently and its depth range and space position can be controlled by the specified parameters.