Figure 4: Onset of chiral optomechanics.

The occurrence of chiral optomechanical effects can be traced by looking at (a) the ratio, k⁺/k⁻, of the spin-dependent force constants and (b) the measured radiation torque, Γ⁺_rad in adimensional units as a function of the particle radius, R₀, normalized to the trapping wavelength, λ. Error bars represent the standard deviation from the average value obtained for each particle data set. The green lines in (a) are calculations obtained by ray optics (dashed green line) and exact T-matrix (solid green line) modeling of optical forces on spherical particles. In (b) the dashed magenta line describes the optical torque transferred by LCP light to an L-chiral flat mirror in terms of its selective reflectivity, R⁺ (equations 2 and 4). The solid magenta line represents T-matrix calculations of the optical torque transferred by LCP light to an L-chiral spherical particle.