Thermo-optical properties of some common laser-dye solvents

Abstract

We have used a laser interferometric method to determine the refractive index of some laser dye solvents with a high accuracy 5.8 × 10 −4. The determination of refractive index ( n) was performed by counting the interfering fringes ( N) as a function of the incidence angle of the laser beam. The absolute refractive index of pure water, Dimethylsulfoxide (DMSO), and deferent mixtures, P (percentage), (25%, 50%, and 75% of DMSO) of them were measured. The relation between the bulk refractive index ( n m) of these mixtures are plotted as a function of the investigated portions ( P). The temperature behavior (d n m/d t) of these refractive indices were studied carefully within a temperature range (from 20°C to 80°C). It was found that both the refractive index ( n m) and temperature behavior of the refractive indices (d n m/d t) of that different mixtures of the investigated solvents are the average index properties of the parent solvents. Also, we did a fitted imperical relation to formulate the relation between n m, P, and t N m = ap b t c; with an imperical constants a, b, and c. According to the equation we recalculated n m of the solvent mixtures and we found an agreement with a very little difference.