Fig. 3

Detailed simulations. a Ray-optics diagrams of the propagation of a focused beam through an optically trapped particle (i) when the particle is at the center of the trap (equilibrium position in the trap that takes into account also the effective gravitational force acting on the particle), (ii) when it is displaced in the radial direction, (iii) when it is displaced along the axial direction downward and (iv) upward. b Radial (r) and axial (z) particle position, and corresponding laser power (P) obtained from the simulation of the motion of a 4.9-μm-diameter polystyrene particle trapped in the intracavity optical trap. c Dependence of the laser power on the radial and axial position of the particle. The points (i)–(iv) correspond to the configurations in (a) and the dashed lines correspond to the insets graphs the dependence on z and r on the left and bottom, respectively