Philip H. Jones, Onofrio M. Maragò & Giovanni Volpe
Fig. 3.8 — Gradient force
(a) Intensity distribution of a Gaussian beam (background) and corresponding optical gradient forces (arrows) on a dielectric particle whose refractive index is higher than that of the surrounding medium. (b) Optical potential along the radial direction (solid line) and its approximation by a harmonic potential (dashed line).