Fig. 10. Experimental results for beam width measurement and modal coupling in two distinct turbulence regions.

a The experimental setup utilizes two longitudinally structured beams, each with narrow beam widths at 0 < z < 0.3 m and 0.3 m < z < 0.6 m, respectively. b Experimentally measured intensity and phase profiles, along with the normalized modal spectra of Beams 1 and 2, for two different turbulence cases where regions 1 and 2 have different r₀ values. Adapted with permission from ref. ¹²⁷