Wavefront reconstruction of a non-diffracting structured laser beam

The Structured Laser Beam (SLB) is a pseudo-non-diffracting laser beam that shares many characteristics with a Bessel beam. However, it can theoretically propagate over an unlimited distance while maintaining an extremely low inner core divergence of only 0.01 mrad. This makes it a promising candidate for precise long-distance alignment applications such as the alignment of particle accelerator components at CERN. In this work, a novel method to assess the symmetrical wavefront aberrations induced by an SLB generator is presented. Our approach is based on the analysis of a single-intensity distribution of an SLB. The coefficients of the Zernike polynomials are estimated using artificial intelligence before least-squares fitting is used to refine the result. This approach ensures that the fitting avoids local minima. This method provides a novel way to analyze the optical aberrations induced by the SLB generator.