 Propagation of a Gaussian Beam Through a Thin Lens by Francesco D'Angelo

Application note explicitly credited to Francesco D'Angelo, Section 2.1 of the Edmund Optics Laser Optics Resource Guide. Equations (1)–(5) define the intensity radius, beam waist, Rayleigh range and far-field half-angle beam divergence of an ideal Gaussian beam. No publication date is asserted.

For wavefront curvature, the same primary application note gives the Gaussian beam wavefront radius in equation (6), the reciprocal complex beam parameter in equation (10), and the thin-lens transformation in equation (16): www.edmundoptics.com/knowledge-center/application-notes/lasers/gaussian-beam-propagation/ . These distinguish wavefront radius from beam radius and connect curvature to the complex beam parameter.