Figure 2
From: Negative Optical Torque
Optical torque for different structures under different incident waves carrying positive angular momentum.
Red: Optical torque versus varying k for Fig. 1(e) (εr = 2.46, a = 0.49 μm, R = 1.0 μm) illuminated by a left circularly polarized plane wave of intensity 1 mW/μm2. Green: Optical torque versus varying a for Fig. 1(a) composed of silicon spheres (εr = 12.6096, R = 1.16a, λ = 1064 nm) in water illuminated by a left circularly polarized plane wave of intensity = 1 mW/μm2. Black: Optical torque versus varying k for Fig. 1(a) (εr = 2.4649, a = 0.5 μm, R = 0.58 μm) illuminated by a left circularly polarized Gaussian beam (numerical aperture = 0.9 and total power = 0.05 W). Yellow: Optical torque versus k for Fig. 1(a) (εr = 2.4649, a = 0.5 μm, R = 0.58 μm) illuminated by a linearly polarized 10 mW Laguerre-Gaussian beam with topological charge of 1 and a N.A. of 0.9. Blue: Optical torque versus k for Fig. 1(e) (εr = 2.4649, a = 0.49 μm, R = 1.0 μm) illuminated by a linearly polarized 10 mW Laguerre-Gaussian beam with topological charge of 1 and a N.A. of 0.9. Negative torque (Γz < 0) means that the light beam induces the object to rotate in the opposite sense as the angular momentum of the incident photon.
