Propagation factor of a new kind of flattened-top beam

A new kind of light beam generated from superposing cosh-Gaussian beams is proposed. Two types of superposing light field with different weight coefficients are disscussed in detail. It was found that the beam profiles have a nearly flat top but its sides reduce contiunously for suitable parameters. The beam may also be a solution of the paraxial wave equation for propagation in complex optical systems because the equation is linear. The propagation factor of cosh-Gaussian beams is calculated in this article.