Flattened light beams with an axial shadow generated through superposing cosh-Gaussian beams

Making use of combining N — L + 1 cosh-Gaussian beams, the beams with nearly flattened top profiles and an on-axial shadow are introduced. An analytical expression of the beams propagating through a first-order ABCD system is derived. The closed expression of the beam propagation factor ( M 2-factor) is presented to characterize the quality of the beams, and the kurtosis parameter is employed to describe the sharpness of such beams. Additionally, the scheme to generate such a light beam is also proposed.