title: Resolution of cross-type optical particle separation.
abstract: A real-time, continuous optical particle separation method, termed cross-type optical particle separation, is investigated theoretically and experimentally. The trajectory of a particle subject to cross-type optical particle separation is predicted by solving the particle dynamic equation and compared with experimental data. For various flow velocities and particle sizes, the retention distances are measured where the displacement perpendicular to the fluid flow direction is referred to as the retention distance. The measured retention distances are in good agreement with theoretical predictions. The retention distance increases as the particle size increases due to the radiation force, but decreases as the flow velocity increases since the residence time of a particle in the laser beam decreases with increasing flow velocity. To evaluate the performance of the cross-type optical particle separation method, size-based separation resolution is derived theoretically in terms of the refractive index of the particle and instrumental fluctuations. Furthermore, an expression for the maximum resolution is derived.
authors.affiliation: Department of Mechanical Engineering Korea Advanced Institute of Science and Technology 373-1, Guseong-dong, Yuseong-gu, Daejeon, 305-701, Korea.
authors.forename: Sang Bok
authors.initials: SB
authors.lastname: Kim
authors.forename: Sang Youl
authors.initials: SY
authors.lastname: Yoon
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Sung
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Kim
mesh_terms: D007834:Lasers; D008027:Light; D009038:Motion; D052898:Optical Tweezers; D010316:Particle Size; D011827:Radiation