| With the rapid development of ultrafast laser technology,the construction and regulation of multidimensional optical fields has received a lot of attention from researchers at home and abroad,and has rapidly become a research hotspot in the field of optics.The multidimensional optical field has been widely used in optical communication,precision measurement,superresolution imaging,optical microimaging and optical micro-manipulation.In order to further guide and control the optical field accurately,high-precision joint temporal and spatial modulation and measurement must be realized.In this paper,based on the combined system of spatial light modulator and lens and phase wavefront reconstruction technology,we realize the construction and control of multi-dimensional spatio-temporal structured optical field.The fundamental characteristics of the optical field are investigated,including trajectory control,anti-interference capability analysis and reversible optical field modulation,weakening and even eliminating the effects of diffraction and dispersion,and joint multiparameter modulation.This work realizes a multidimensional spatiotemporal vortex light field carrying orbital angular momentum,and also broadens the application scenarios of multidimensional spatiotemporal structured vortex light fields,which helps to explore the potential applications of spatiotemporal light fields with excellent properties.The main contents are as follows:(1)Based on the optical Airy transform method,a new method is proposed to generate controllable Airy-like vortex beams by phase reconstruction and orbital angular momentum implantation of hollow Gaussian beams.By encoding a cubic spiral phase mask on the spatial light modulator and performing a two-dimensional Fourier transform on the incident beam reflected by the spatial light modulator screen,a hollow Airy-like vortex beam with the dual characteristics of optical vortex and Airy beam is generated in the output plane.By modulating the order of the incident beam,the control coefficient of the phase mask and other related parameters,the modal switching between the Gaussian beam,the optical vortex,the Airy beam and their combinations can be easily realized.(2)Based on the(3+1)D Schr(?)dinger equation,a new scheme combining a weakly chirped Airy pulse without initial velocity in the time domain and a diffraction-free Bessel beam in the air domain is proposed to construct a chirped Airy-Bessel vortex spatiotemporal wave packet.The dependence of the diffraction-free propagation and self-focusing effects of the target wave packet on the topological charge and chirp parameters are investigated,and the transmission dynamics properties of the chirped Airy-Bessel vortex spatiotemporal wave packet in the spatiotemporal domain from the perspectives of phase structure,energy flow distribution and orbital angular momentum density are elaborated,and the separation and combination of the intertwined time and space variables are realized.(3)Based on the Wigner distribution function method,a multidimensional oblique AiryAiry vortex wave packet in the phase momentum space is constructed.The spatiotemporal dynamics of the Wigner distribution function oblique Airy-Airy vortex wave packet propagating in a dispersive chiral medium is investigated from the perspectives of the nonclassical nature,propagation characteristics and angular momentum density of the target wave packet.The nonclassical nature of this wave packet is investigated to correlate the optical field in the phase momentum space with that in the real space,providing information on the joint position and phase momentum distribution in arbitrary real space coordinates.(4)Based on the Richards-Wolf vector diffraction theory,a scheme is proposed to generate a superchiral optical field in a 4π microscopic system by tightly focused two helical phase wavefronts.The coherent interference of two counter-propagating column vector vortex beams is used to improve the focused efficiency,and the orbital angular momentum state of photons is introduced to enhance the vortex circular dichroism of the focusing field to achieve the superchiral enhancement of the local optical field at the focal point.The optical forces and moments exerted by the superchiral optical field on the chiral dipole are calculated,and the chiral optical force effect experienced by the excited particle is characterized using the chiral density and flux.Selective separation of different particles is achieved by varying the sign of the orbital angular momentum state of the incident photon and the chiral factor to adjust the optical force difference of the chiral dipole when it is excited by the opposite state of the photon. |
