Chiral lateral optical force near plasmonic ring induced by Laguerre-Gaussian beam

Owing to the good adjustability and the strong near-field enhancement, surface plasmons are widely used in optical force trap, thus the optical force trap can achieve excellent performance. Here, we use the Laguerre-Gaussian beam and a plasmonic gold ring to separate enantiomers by the chiral optical force. Along with the radial optical force that traps the particles, there is also a chirality-sign-sensitive lateral force arising from the optical spin angular momentum, which is caused by the interaction between optical orbit angular momentum and gold ring structure. By selecting a specific incident wavelength, the strong angular scattering and non-chiral related azimuthal optical force can be suppressed. Thus the chiral related azimuthal optical force can induce an opposite orbital rotation of the trapped particles with chirality of different sign near the gold ring. This work proposes an effective approach for catchingand separating chiral enantiomers.     

原子力显微镜-扫描电子显微镜共定位表征系统的研发与应用

微纳加工过程中,常有样品需要进行聚焦离子束（FIB）溅射、切割,扫描电子显微镜（SEM）以及原子力显微镜（AFM）表征,而这三类仪器都需要将样品固定在样品台上才可测试,固定不佳会影响表征结果.但固定好的样品在不同仪器之间转移、拆卸、再固定的过程中极易受到破坏.基于以上问题,设计了AFM-SEM-FIB样品共定位系统,可实现样品在此三种仪器之间的无损转移及共定位,避免珍贵样品破坏及目标丢失,以及解决AFM扫描无法控制方向、迅速调整位点等问题.在微纳表征中有优异的表现,系统已被开发成产品并量产销售.