Figure 2.14 — Optical force and torque on a cylinder Figure 2.14 — Optical force and torque on a cylinder. (a) Multiple scattering of a light ray impinging on a cylinder visualised in three dimensions. Note that, differently from the case of a sphere [Fig. 2.6], the reflected and transmitted rays are not all on the same plane. (b) Optical forces (white arrows) and torques (black arrows) produced by two light rays impinging on a cylinder at a large angle. The torque tends to align the cylinder along the optical axis. In all cases, there is a scattering force pushing the cylinder along the optical axis.