Research On Light Field Control Of Hollow Cylindrical Vector Beams

The polarization characteristics of hollow cylindrical vector beams had the axis symmetry under the propagated process.The hollow cylindrical vector beams had the superior characteristics after focused by high numerical aperture lens that become a research hotspot in recent time.The obtained focusing structure fields had the potential applications in particles trapping and transportation,optical microscope,perpendicular magnetic recording,and multichannel magnetic data storage and so on.In this dissertation,the main contents can be summarized into the following four aspects.The generation of optical needle by tightly focusing electromagnetic dipole reversing radiation field was investigated.And the transformation among the transverse polarized,longitudinal polarized and the three-dimensional polarized optical needle was investigated in the focal region,respectively.It was found that the focusing depth of optical needle was mainly depended on the numbers of electromagnetic dipole pairs.The focusing depth of three-dimensional polarized optical needle can reach to 16.57?,and the full width at half maximum of the optical needle can reach to 0.398? by tightly focusing 6 pairs of electromagnetic dipoles in the focal region.The three-dimensional polarized optical chain and dark channel was obtained by well-designed annular aperture filters modulated under the illumination of the mixed incident radially polarized and azimuthally polarized hollow Gaussian beams in the focal region.The obtained optical chain and dark channel can be shifted along the optical axis by introducing the phase difference of two counter-propagating incident beams.The focusing depth of the obtained three-dimensional polarized optical chain and dark channel can reach to 40? in the focal region.The magnetic sphere size of 0.3844? was achieved by modulating the beam order and relative beam waist of cylindrically polarized sinh-Gaussian beams in the focal region.Furthermore,the magnetic sphere was inverted by changing the rotate direction of the spiral phase plate under the same focusing conditions in the focal region.The pure longitudinal magnetization chain and hollow dark channel was generated by well-designed annular aperture filters modulated the azimuthally polarized hollow Gaussian beams in the focal region.The obtained pure longitudinal magnetization chain and magnetization hollow dark channel can be shifted along the optical axis by introducing the phase difference of two inverse propagated incident beams.And the shifted distance was proportional to the phase difference.The axial focusing depth of the obtained magnetization chain and magnetization hollow dark channel can reach to30?.