(a)–(c) Experimental results (rectangles) for the normalized IC function of the GSM beams of different spatial coherence widths propagating through the lab-simulated turbulence as measured by the fast detector. The solid curves correspond to the product of the two terms: g(x,0,z), displayed in Fig. 3 and 1 + B_I(r, 0,z), shown in Fig. 4. (d) The maximum of the normalized IC, attained at r₁ = r₂ = 0, as a function of the spatial coherence width δ_c of the GSM beam, measured by the slow detector in the turbulent medium (rectangles), fast detector in the absence of turbulence (circles), and the fast detector in the turbulent medium (diamonds). The solid curve corresponds to the product of the experimental data displayed with rectangles and circles.