Abstract

An experimental campaign for the propagation of laser modes carrying orbital angular momentum (OAM) over 1 kilometer has been established at UANDES university campus. We describe our method for estimating OAM spectra and the average topological charge values from the images delivered by Shack-Hartmann sensor. For OAM beams transmitted with a single topological charge we analyze the average departure of the measured charge with respect to the intended one and the spread of these values as a function of turbulence strength.