Abstract

Some characteristic parameters of the Bessel- Gaussian beam were determined theoretically by direct analytical calculations. Variation of the final beam radius (ω) with the starting beam radius (ω_o) was studied. The Rayleigh range of a Bessel-Gauss beam was calculated for each value of the minimum starting beam radius. The beam wavefront radius of curvature (R) was calculated as a function of  starting beam radius at different distances from the source. A modified Bessel-Gauss beam was also considered. The beam intensity was calculated in the waist plane. The variation of the intensity near the center depends on whether the radius (a) equal, less than or greater than the starting beam radius (ω_o).

Key words: Bessel- Gauss beam, beam radius, waist plane, intensity.