Optical singularity states,which significantly affect propagation properties of light in free space or optical medium,can be geometrically classified into screw and edge types.These different types of singularity stat...Optical singularity states,which significantly affect propagation properties of light in free space or optical medium,can be geometrically classified into screw and edge types.These different types of singularity states do not exhibit direct connection,being decoupled from each other in the absence of external perturbations.Here we demonstrate a novel optical process in which a higher-order edge singularity state initially nested in the propagating Gaussian light field gradually involves into a screw singularity with a new-born topological charge determined by order of the edge state.The considered edge state comprises an equal superposition of oppositely charged vortex and antivortex modes.We theoretically and experimentally realize this edge-to-screw conversion process by introducing intrinsic vortex–antivortex interaction.We also present a geometrical representation for mapping this dynamical process,based on the higher-order orbital Poincarésphere.Within this framework,the edge-to-screw conversion is explained by a mapping of state evolution from the equator to the north or south pole of the Poincarésphere.Our demonstration provides a novel approach for manipulating singularity state by the intrinsic vortex–antivortex interactions.The presented phenomenon can be also generalized to other wave systems such as matter wave,water wave,and acoustic wave.展开更多
Tiny but universal beam shifts occur when a polarized light beam is reflected upon a planar interface.Although the beam shifts of Gaussian beams have been measured by the weak measurement technique, the weak measureme...Tiny but universal beam shifts occur when a polarized light beam is reflected upon a planar interface.Although the beam shifts of Gaussian beams have been measured by the weak measurement technique, the weak measurement for orbital angular momentum(OAM)-induced spatial shifts of vortex beams is still missing.Here, by elaborately choosing the preselection and postselection states, the tiny OAM-induced Goos–H?nchen and Imbert–Fedorov shifts are amplified at an air–prism interface. The maximum shifts along directions both parallel and perpendicular to the incident plane are theoretically predicted and experimentally verified with optimal preselection and postselection states. These maximum shifts can be used to determine the OAM of vortex beams.展开更多
基金National Natural Science Foundation of China(12304358,12374306,62175091)Guangzhou Science and Technology Program(202201020061)Fundamental Research Funds for the Central Universities(21623331)。
文摘Optical singularity states,which significantly affect propagation properties of light in free space or optical medium,can be geometrically classified into screw and edge types.These different types of singularity states do not exhibit direct connection,being decoupled from each other in the absence of external perturbations.Here we demonstrate a novel optical process in which a higher-order edge singularity state initially nested in the propagating Gaussian light field gradually involves into a screw singularity with a new-born topological charge determined by order of the edge state.The considered edge state comprises an equal superposition of oppositely charged vortex and antivortex modes.We theoretically and experimentally realize this edge-to-screw conversion process by introducing intrinsic vortex–antivortex interaction.We also present a geometrical representation for mapping this dynamical process,based on the higher-order orbital Poincarésphere.Within this framework,the edge-to-screw conversion is explained by a mapping of state evolution from the equator to the north or south pole of the Poincarésphere.Our demonstration provides a novel approach for manipulating singularity state by the intrinsic vortex–antivortex interactions.The presented phenomenon can be also generalized to other wave systems such as matter wave,water wave,and acoustic wave.
基金National Natural Science Foundation of China(11604050,61475066,61675092,61705086)Natural Science Foundation of Guangdong Province(2016A030311019,2016A030313079,2016TQ03X962,2017A010102006,2017A030313359,2017A030313375)Science Technology Project of Guangzhou(201604040005,201605030002,201704030105,201707010396,201803020023)
文摘Tiny but universal beam shifts occur when a polarized light beam is reflected upon a planar interface.Although the beam shifts of Gaussian beams have been measured by the weak measurement technique, the weak measurement for orbital angular momentum(OAM)-induced spatial shifts of vortex beams is still missing.Here, by elaborately choosing the preselection and postselection states, the tiny OAM-induced Goos–H?nchen and Imbert–Fedorov shifts are amplified at an air–prism interface. The maximum shifts along directions both parallel and perpendicular to the incident plane are theoretically predicted and experimentally verified with optimal preselection and postselection states. These maximum shifts can be used to determine the OAM of vortex beams.
