title: Stable trapping and manually controlled rotation of an asymmetric or birefringent microparticle using dual-mode split-beam optical tweezers.
abstract: Inserting a coverslip into half of a Gaussian laser beam at a suitable tilting angle can make the single-mode laser beam become closely spaced dual light spots at the laser focus. In this way, we can reform the conventional single-beam optical tweezers easily and construct a set of dual-mode split-beam optical tweezers, which can be used to manually rotate a trapped and twisted red blood cell around the optical axis. Furthermore, we demonstrate that the split-beam optical tweezers can also stably trap and orient a birefringent polystyrene micro strip particle, which otherwise will self rotate at a varying speed along the structural principal axes, fast spin about the optical axis in a tilting pose, or precess like a gyroscope, in the original linearly polarized single-beam optical tweezers.
authors.affiliation: Department of Applied Physics, National Chiayi University, Chiayi 60004, Taiwan. fwsheu@mail.ncyu.edu.tw
authors.forename: Fang-Wen
authors.initials: FW
authors.lastname: Sheu
authors.forename: Tzu-Kai
authors.initials: TK
authors.lastname: Lan
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Lin
authors.forename: Shiung
authors.initials: S
authors.lastname: Chen
authors.forename: Chyung
authors.initials: C
authors.lastname: Ay