Content deleted Content added
m →One-speckle diffusing-wave spectroscopy: replace et al. in author/editor parameters with |display-authors=etal or |display-editors=etal; using AWB |
m →One-speckle diffusing-wave spectroscopy: Typo/general fixes, replaced: relation ship → relationship using AWB |
||
Line 21:
==One-speckle diffusing-wave spectroscopy==
Laser light is sent to the sample and the outcoming transmitted or backscattered light is detected by an optoelectric sensor. The light intensity detected is the result of the interference of all the optical waves coming from the different light paths.
<gallery>
Line 46:
with <math>k_0=\frac{2\pi n}{\lambda}</math> and <math>l*</math> is the transport mean free path of scattered light.
For simple cell geometries, it is thus possible to calculate the mean squared displacement of the particles <Δr<sup>2</sup>> from the measured g<sub>2</sub>-1 values analytically. For example, for the backscattering geometry, an infinitely thick cell, large laser spot illumination and detection of photons coming from the center of the spot, the
<math>g_2(\tau)-1=\exp\left(-2 \gamma \sqrt{\langle\Delta r^2(\tau)\rangle k_0^2}\right)</math>, γ value is around 2.
| |||