Fig. 2. Reversible optical lateral force on Mie chiral particles induced by the effect of the incident angle and particle size.

a Over the whole range of incident angles and for both s- and p-polarization, the 100-nm dipole chiral particle experiences positive and negative optical lateral forces when κ = −0.4 and κ = +0.4, respectively. b The sign of the optical lateral force reverses under different angles for the 1-μm chiral particle. c–e Sketch of the incident angle-induced optical lateral force. f The optical lateral force reverses sign when the incident angle is small (θ = 10°) even for large particles (R = 800‒1000 nm). g The sign of the lateral force at 45° is also different from that at 80° for large particles under the p-polarized beam