Focus Modulation Of Cylindrical Vector Beams Based On Artificial Microstructure Materials

Cylindrical Vector Beam(CVB)is a kind of beam with unique electrical polarization state distribution.CVB can be divided into radial polarized light and azimuthal polarized light according to the spatial distributions of their electric field.This interesting polarization state makes it posiblely used in the sub-wavelength imaging,optical micro-manipulation,optical data storage and other fields.Some of the unique effects that can be achieved by artificial microstructures,such as the bandgap effect of photonic crystals,the equivalent negative refraction effect of subwavelength gratings and the hyperbolic dispersion properties of hyperbolic metamaterials,can achieve the effects of CVB Control of spatial distribution.In this paper,we mainly talk about using artificial microstructure materials to achieve sub-wavelength focusing on CVB.Theese work can be divided into three parts.The first part is talking about negative refraction effect of one-dimensional photonic crystal and then get a plano concave lens,which can be used,to focus any polarization states of CVB;Secondly,in order to reduce the inherent loss of one-dimensional photonic crystal plano concave lens,we combined subwavelength grating’s equivalent negative refraction effect and the Fermat principle to get an all-dielectric grating plano concave lens,these kind of lens only exists diffraction loss at the exit surface and the interference process,the above two kinds of lens structure of the scale and the incident light wavelength of is on the same order(about less than 1/2 ?).The third part discusses the use of hyperbolic metamaterials with smaller(1/20 ? or smaller)structural elements to try to focus CVB.In this paper,the optical characteristics of the related artificial microstructure materials and the spatial distribution characteristics of CVB are studied.Finally,several artificial microstructure lenses can be focused CVB,and the morphology of CVB and the focusing position Flexible adjustment.