Wang Sicong, Zhou Zhikai, Zheng Zecan, Sun Jialin, Cao Hongkun, Song Shichao, Deng Zi-Lan, Qin Fei, Cao Yaoyu, Li Xiangping
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, <a href="https://ror.org/02xe5ns62">Jinan University</a>, Guangzhou 510632, China and College of Physics & Optoelectronic Engineering, <a href="https://ror.org/02xe5ns62">Jinan University</a>, Guangzhou 510632, China.
Phys Rev Lett. 2024 Aug 16;133(7):073802. doi: 10.1103/PhysRevLett.133.073802.
Topological properties of energy flow of light are fundamentally interesting and may introduce novel physical phenomena associated with directional light scattering and optical trapping. In this Letter, skyrmionlike structures formed by Poynting vectors are unveiled in the focal region of two pairs of counterpropagating cylindrical vector vortex beams in free space. The appearance of local phase singularities, and the distinct traveling and standing wave modes of different field components passing through the focal spot lead to a Néel-Bloch-Néel transition of Poynting vector skyrmion textures along the light propagating direction. By shaping the wave front of the incident beams with patterned amplitudes, the topological invariant of the Poynting vector skyrmions can be further tuned in a prospective area. This work expands the family of optical skyrmions and holds great potential in energy flow associated applications.
光能量流的拓扑性质从根本上来说很有趣，并且可能会引入与定向光散射和光学捕获相关的新颖物理现象。在本信函中，由坡印廷矢量形成的类斯格明子结构在自由空间中两对反向传播的圆柱矢量涡旋光束的焦区被揭示出来。局部相位奇点的出现，以及不同场分量穿过焦点时不同的行波和驻波模式，导致了坡印廷矢量斯格明子纹理沿光传播方向的奈尔 - 布洛赫 - 奈尔转变。通过用图案化幅度对入射光束的波前进行整形，坡印廷矢量斯格明子的拓扑不变量可以在一个预期区域内进一步调整。这项工作扩展了光学斯格明子的家族，并且在与能量流相关的应用中具有巨大潜力。
