Theoretical And Experimental Researches On The Propagation Properties Of The Anomalous Vortex Beam

Recently,with the rapid development of singular optics,researchers have carried out extensive research on the wavefront dislocations and topologies appearing near the phase singularity of the optical wave field.Vortex beams is one of the Singular Optics.And since its unique phase distribution,the vortex beam has been widely used in optical information encoding,optical spatial transmission,quantum information conversion,particle trapping and manipulation,etc.So based on the unique properties of vortex beams,we choose the special anomalous vortex hollow beam,anomalous Bessel beam and partially coherent radially polarized vortex beam as the target beam.We mainly studied the generation and the propagation properties of anomalous vortex hollow beam and anomalous Bessel beam,and the coupling efficiency of partially coherent radially polarized vortex beam in single-mode fiber had been also studied.Firstly,we calculate the formula of non-paraxial anomalous vortex hollow beam in free space with the Rayleigh-sommerfeld integral formula.Then,we study the comparison of the propagation properties between the paraxial and non-paraxial target beam by numerical examples,as well as the phase and intensity distributions.We found that the intensity and phase of the target beams are closely related to the topological charge number.Secondly,through designing the helical slit,the generation and the propagation properties of anomalous vortex Bessel beams has been given both in theory and experiments.The local topological charge of the central beam is inversely proportional to the propagation distance.It has important implications for quantum information optics.Finally,by using the cross-spectral density matrix of the partially coherent diameter-polarized beam,we obtain the coupling efficiency of the target beam into the single-mode fiber.The results showed that the coupling efficiency is significantly affected by the numerical aperture and parameters of the incident beam as topological charge,initial spatial coherence and wavelength and we also figure out the best choice for the PCRP vortex beams with different parameters.