Toselli, ItaloItaloToselliGladysz, SzymonSzymonGladysz2022-10-242022-10-242022https://publica.fraunhofer.de/handle/publica/42787010.1117/12.2632455The analysis of free-space optical system performances requires the calculation of several metrics of the turbulence-affected collected light. One of the most useful of these metrics is the long-term beam spread in the focal plane, where the detector (or optical fiber) should be located. In this paper, we use the ABCD ray-matrix formalism to show the impact of Kolmogorov and non-Kolmogorov turbulence on the long-term beam spread in the focal plane.enconference paper