Fig. 2.

Flowchart of LSR processing algorithm (adapted with modifications from Refs. ³⁵ and ⁴²). Box 1: speckle images are acquired at both cross- and co-polarized states, with respect to linear polarization of the illumination beam. Box 2: cross-correlating the first speckle frame with subsequent frames provides the speckle intensity autocorrelation function, $g_2(t)$. Box 3: temporal averaging of speckle frames returns the DRP at both cross- and co-polarized states. Box 4: the ${\mu }_a$ and ${{\mu }_s}^{\prime }$ are experimentally evaluated via curve-fitting to the radial cross-polarized DRP. Box 5: optical properties determine whether the DWS formalism, i.e., $g_2(t)=\exp -2\gamma \surd [k^2⟨\mathrm{\Delta }{r}^2(t)⟩+3{\mu }_a/{{\mu }_s}^{\prime }]$ or the modified MCRT-driven equation, i.e., $g_2(t)=\exp -2\gamma {[k^2⟨\mathrm{\Delta }{r}^2(t)⟩]}^{\zeta }$, should be used to deduce the MSD. Box 6: the ratio of co-polarized DRP along short and long axes, i.e., $\hat{I}=I(\phi =90\mathrm{deg})/I(\phi =0\mathrm{deg})$, is compared with a calibration curve to evaluate the average radius of scattering particles, $a$. Box 7: MSD and $a$ are substituted in GSER to calculate the $G^{*}(\omega )$.