Vol. 54, Issue 3, pp. 283-302 (2024)

Abstract

This research focuses on the analysis of laser beam shape propagation properties and the generalized beam shaping of the fundamental Gaussian mode, Hermite–Gaussian modes and Laguerre–Gaussian modes, which were studied analytically and numerically using the angular spectrum technique and the 2D fast Fourier transformation procedures. The fundamental Gaussian mode is applied here as the reference for checking the accuracy of beam profile analysis based on multiple scanning knife-edge method. A set of spatial profile curves is generated, each of which represents the intensity profile of the fundamental Gaussian mode for different directions of propagation. The He-Ne laser and the diode laser are used as the probe lasers. The experimental results show that the He-Ne laser emits a pure fundamental Gaussian mode, whereas the diode laser emits an elliptical beam shape. Some numerical simulation examples of the generated beams are also given to illustrate the propagation properties of the fundamental Gaussian mode, Hermite–Gaussian modes, and Laguerre–Gaussian modes.