. 2016 Nov 1;7(12):4859–4873. doi: 10.1364/BOE.7.004859

Table 1. Speckle visibility with different scattering regimes and velocity distributions.

Scattering regime	Velocity distribution	Speckle visibility expression, where x = T/τ_c
Single	Lorentzian (Brownian motion)	$K (T, τ_{c}) = β^{1 / 2} {[ρ^{2} \frac{\exp (- 2 x) - 1 + 2 x}{2 x^{2}} + 4 ρ (1 - ρ) \frac{\exp (- x) - 1 + x}{x^{2}} + {(1 - ρ)}^{2}]}^{1 / 2} + C_{n o i s e}$ [21]
Single	Gaussian (directional flow)	$\begin{matrix} K (T, τ_{c}) = β^{1 / 2} [ρ^{2} \frac{\exp (- 2 x^{2}) - 1 + \sqrt{2 π} x e r f (\sqrt{2} x)}{2 x^{2}} \\ {+ 2 ρ (1 - ρ) \frac{\exp (- x^{2}) - 1 + \sqrt{π} x e r f (x)}{x^{2}} + {(1 - ρ)}^{2}]}^{1 / 2} + C_{n o i s e} \end{matrix}$ [22]
Multiple	Gaussian (directional flow)	_{$\begin{matrix} K (T, τ_{c}) = β^{1 / 2} [ρ^{2} \frac{\exp (- 2 N_{d} x) - 1 + 2 N_{d} x)}{2 {N_{d}}^{2} x^{2}} \\ {+ 4 ρ (1 - ρ) \frac{\exp (- N_{d} x) - 1 + N_{d} x}{{N_{d}}^{2} x^{2}} + {(1 - ρ)}^{2}]}^{1 / 2} + C_{n o i s e} \end{matrix}$} [21]