Investigating Auto-correlation of Scattered Light of Mixed Particles

In this work, the normalized time auto-correlation function of the electric field of the light $g^{(1)}(\tau)$ that is scattered by the two kinds of particles in dispersion is investigated. The results show that the logarithm of $g^{(1)}(\tau)$ can be consistent with a line and many reasons can cause the deviations between an exponentiality and plots of $g^{(1)}(\tau)$ as a function of delay time $\tau$. The nonexponentiality of $g^{(1)}(\tau)$ is not only determined by the particle size distribution and scattering angle but also greatly influenced by the relationship between the concentrations, mass densities and the values that the refractive index of the material expands as a function of the concentration of the two kinds of particles.