On the Critical Behavior of Phase Changes of a Forward-Scattered Light in a Nonpolar Binary Liquid Mixture

The effect of concentration fluctuations on the changes of azimuth and ellipticity are analytically obtained in a binary chiral liquid mixture, when the incident light is completely linearly polarized above (or below) thehorizontal at 45°. The important results are as follows; (1) When the binary liquid is in the critical region far from the critical point, the ellipticity change is proportional to isothermal compressibility factor and the fifth order of frequency. As the system approaches very close to the critical point, the change is proportional to the third order of frequency and shows the logarithmic divergence. (2) In the case that the system is in the critical region far from the critical point, the azimuth change is solely due to the molecular contribution. As the system approaches to the critical point, the effect of fluctuations becomes important. If it is in the extreme close to the critical point, the term due to the concentration fluctuations is comparable to or larger than the molecular contribution.