Enantioselective Optical Trapping of Multiple Pairs of Enantiomers by Focused Hybrid Polarized Beams

Enantiomers (opposite chiral molecules) usually exhibit different effects when interacting with chiral agents, thus the identification and separation of enantiomers are of importance in pharmaceuticals and agrochemicals. Here an optical approach is proposed to enantioselective trapping of multiple pairs of enantiomers by a focused hybrid polarized beam. Numerical results indicate that such a focused beam shows multiple local optical chirality of opposite signs in the focal plane, and can trap the corresponding enantiomers near the extreme value of optical chirality density according to the handedness of enantiomers. The number and positions of trapped enantiomers can be changed by altering the value and sign of polarization orders of hybrid polarized beams, respectively. The key to realizing enantioselective optical trapping of enantiomers is that the chiral optical force exerted on enantiomers in this focused field is stronger than the achiral optical force. The results provide insight into the optical identification and separation of multiple pairs of enantiomers and will find applications in chiral detection and sensing. This work proposes an optical approach to enantioselective trapping of multiple pairs of nano-enantiomers (S and R) by a type of hybrid polarized beams. The enantiomers with opposite chirality can be trapped at different positions depending on whether the handedness of enantiomer matches the sign of optical chiral density at the trapping positions (P1-P6).image