Figure 8

Beam propagation in the absence of the scattering force, i.e., only dipole force is considered, and zero particle temperature for a light beam power of (a) 0.1 TW and (b) 1 TW. The over-focusing effect is demonstrated through (a1, b1) the normalized light intensity with four representative particle trajectories and min and max values corresponding to 0.1 and 2.5, (a2, b2) the normalized particle density with min and max values corresponding to 0.1 and 4, and (a3, b3) the radial kinetic energies, \(E_K\), of the particles compared with the depth of the light potential well, \(\Phi _d\), at each axial location. The energies, E, are normalized by \(U_{\mathrm{ref}}=2.76\times 10^{-24}\) J.