Figure 6.

Scheme of the optical field determination from a Gaussian laser beam with the paraxial ray optics approach. (a) The power carried by each ray, is calculated as the integral of the beam intensity, as a function of the radial coordinate within the area of the annulus associated to the ray; (b) The amplitude A(ρ, z) and the (c) curvature radius R(ρ, z) along the axis z are calculated, which will be exploited respectively for the evaluation of the power and the propagation direction of each ray.