Gaussian beams

Complex-beam-parameter (Gaussian) wave optics: Kogelnik and Li’s ABCD transformation of the complex beam parameter through a thin lens, Siegman’s \(M^2\) beam-quality factor for real, non-diffraction-limited beams, and the doughnut intensity and helical phase of an Allen et al. Laguerre-Gaussian orbital-angular-momentum vortex.

Kogelnik and Li: focusing a Gaussian beam through a thin lens

Kogelnik and Li: focusing a Gaussian beam through a thin lens

Siegman’s M^2 beam-quality factor

Siegman's M^2 beam-quality factor

Allen et al.: orbital angular momentum of a Laguerre-Gaussian vortex

Allen et al.: orbital angular momentum of a Laguerre-Gaussian vortex