Fig. 2
From: Long-range spatio-temporal correlations in multimode fibers for pulse delivery
Spatio-temporal correlations in MMF with strong random mode mixing. a Intensity correlations \(C({\mathrm{\Delta }}r,t) \equiv C(|{\bf{\Delta}}{\mathbf{r}}|,t,t{\prime} = t)\), revealing a short-range component C1(t) ≈ 1 at spatial distance within one speckle (\({\mathrm{\Delta }}r \lesssim 3\) μm) and a long-range component C2(t) that persists at large distance. b Two cross sections of C(Δr, t) at arrival times t = −17.3 ps and t = 3.7 ps. c Time dependence of the long-range component C2(t), averaging over Δr for Δr > 5 μm. The error bars represent the standard deviation among four measurements of the fiber in different bending configurations. d Long-range correlations C2(t, t′) between spatio-temporal speckle grains at different arrival times t and t′. e Cross sections of C2(t, t′) at t′ = −17.3 ps, 3.7 ps and 16.1 ps (marked by white dashed lines in d)
