Figure 2: Spatio-spectral speckle measurement.
From: Spatio-temporal focusing of an ultrafast pulse through a multiply scattering medium
Experimental reconstruction of the spatio-spectral speckle electric field Eout(ω, y) after propagation through a multiply scattering medium. (a) Speckle intensity (Int.) |Eout(ω, y)|2, with respective projections onto the spatial (red) and spectral (green) axes—individual slices (solid lines) and integrated signals (dashed lines) are considered. (b) Speckle phase φout(ω, y), along with a spectral phase measurement φout(ω, y0) localized along a single spatial slice. (c) Autocorrelation function |〈Eout(ω, y)Eout*(ω′, y′)〉| demonstrating that the speckle is well resolved both spatially and spectrally. The spatial correlation length is related to the speckle grain size, while the spectral correlation length is the bandwidth of the medium, inversely proportional to the Thouless time.
