title: All-Optical Chirality-Sensitive Sorting via Reversible Lateral Forces in Interference Fields.
abstract: Separating substances by their chirality faces great challenges as well as opportunities in chemistry and biology. In this study, we propose an all-optical solution for passive sorting of chiral objects using chirality-dependent lateral optical forces induced by judiciously interfered fields. First, we investigate the optical forces when the chiral objects are situated in the interference field formed by two plane waves with arbitrary polarization states. When the plane waves are either linearly or circularly polarized, nonzero lateral forces are found at the particle's trapping positions, making such sideways motions observable. Although the lateral forces have different magnitudes on particles with different chirality, their directions are the same for opposite handedness particles, rendering it difficult to separate the chiral particles. We further solve the sorting problem by investigating more complicated polarization states. Finally, we achieve the chiral-selective separation by illuminating only one beam toward the chiral substance situated at an interface between two media, taking advantage of the native interference between the incident and reflective beams at the interface. Our study provides a robust and insightful approach to sort chiral substances and biomolecules with plausible optical setups.
authors.affiliation: Graduate School for Integrative Sciences and Engineering, National University of Singapore , Centre for Life Sciences (CeLS), #05-01, 28 Medical Drive, Singapore 117456, Singapore.|Department of Electrical and Computer Engineering and #Department of Biomedical Engineering, National University of Singapore , 4 Engineering Drive 3, Singapore 117583, Singapore.
authors.forename: Tianhang
authors.identifier: 0000-0002-7939-5302
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Electrical and Computer Engineering and #Department of Biomedical Engineering, National University of Singapore , 4 Engineering Drive 3, Singapore 117583, Singapore.|Department of Electrical & Computer Engineering, North South University , Bashundhara, Dhaka 1229, Bangladesh.
authors.forename: Mahdy Rahman Chowdhury
authors.identifier: 0000-0003-3737-0315
authors.initials: MRC
authors.lastname: Mahdy
authors.affiliation: Department of Mechanical and Industrial Engineering, Department of Electrical and Computer Engineering, Northeastern University , Boston, Massachusetts 02115, United States.
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science Technology and Research (A*STAR) , #08-03, 2 Fusionopolis Way, Innovis 138634, Singapore.
authors.forename: Jing Hua
authors.identifier: 0000-0001-5331-3092
authors.initials: JH
authors.lastname: Teng
authors.affiliation: Graduate School for Integrative Sciences and Engineering, National University of Singapore , Centre for Life Sciences (CeLS), #05-01, 28 Medical Drive, Singapore 117456, Singapore.
authors.forename: Chwee Teck
authors.initials: CT
authors.lastname: Lim
authors.affiliation: Department of Electrical and Computer Engineering, University of Texas at Austin , 2501 Speedway, Austin, Texas 78712, United States.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Graduate School for Integrative Sciences and Engineering, National University of Singapore , Centre for Life Sciences (CeLS), #05-01, 28 Medical Drive, Singapore 117456, Singapore.|Department of Electrical and Computer Engineering and #Department of Biomedical Engineering, National University of Singapore , 4 Engineering Drive 3, Singapore 117583, Singapore.
authors.forename: Cheng-Wei
authors.identifier: 0000-0002-6605-500X
authors.initials: CW
authors.lastname: Qiu
keywords: chirality; interface; interference field; lateral forces; optical forces; separating