Development of Low-Cost Abbe Refractometer

Refractive index and Abbe number are major physical properties of optical materials including glasses and transparent polymers. Refractive index is, in fact, not a constant number and is varied as a function of optical wavelength. The full refractive index spectrum can be obtained using a spectrometer. However, for optical component designers, three refractive indices at the wavelengths of 486.1 nm, 589.3 nm and 656.3 nm are usually sufficient for most of the design tasks, since the rest of the spectrum can be predicted by mathematical models and interpolation. In this paper, we propose a simple optical instrumental setup that determines the refractive indices at three wavelengths and the Abbe number of solid and liquid materials.

Influence of Inorganic Salts on the Refraction Index of Water

The refractive index of double-distilled water and inorganic salt solutions of concentrations varying from 0.4 to 100 ppt (‰) have been measured at 20 Celsius degrees using Abbe refractometer, respectively. The inorganic salts such as NaCl, MgSO4, KCl and MgCl2,these forming the major constituents of seawater are used as solutes of the water solution. The effect of the concentration of these constituents on the refractive index of the solution is experimentally investigated. And meanwhile, the index of refraction studies are carried out for the laser wavelength of 405nm, 450nm, 532nm and 633nm under the case of varying concentration. The results show that the refractive index of the solution will be linearly increased with the increase of the concentration of these constituents. The index of refraction differs for the different solutes when their concentration is same at a certain wavelength.

Optical properties of a liquid crystal with small ordinary and extraordinary refractive indices and small optical anisotropy

Optical properties of a nematic liquid crystal with small refractive index and small birefringence were studied. The ordinary and extraordinary refractive indices and birefringence were measured as functions of temperature by using an Abbe refractometer and wedge nematic cells. From values of these indices the nematic orientational order parameter was calculated by using several methods and corresponding mathematical models. Kuczyński et al. method was found to be suitable for determining the order parameter also for materials featuring small ordinary refractive index, with unknown density.

Development of Barium Borosilicate Glass Using Rice Husk Ash: Effect of BaO

This paper is report on the physical and optical properties of development barium-borate-rice husk ash (BaBRHA) glass system. The glasses containing BaO in xBaO:(80-x)B2O3:20RHA where x = 30, 35, 40 and 45 wt% have been prepared by melt quenching technique. The physical properties of this glass are shown from density data. The optical properties were investigated from refractive index and transmission by using Abbe-refractometer and UV-visible spectrometer respectively.

Study of Variation in Order Parameter with Temperature of Mixtures of Nematic and Cholesteryl Liquid Crystal

The mixtures of nematic [4-Hexyloxy-4-Biphenyl carbonitrile] and cholesteryl propionate were investigated at various temperatures. Measurements of refractive index and transition temperatures were noted by using an Abbe refractometer with a heating arrangement. Ordinary and extraordinary refractive indices were obtained which helped us in calculating the order parameter and its variation with temperature. We also carried out Fabry-Perot Scattering Studies (FPSS) on our samples to confirm the various transition temperatures. Photographs of liquid crystal mixture samples placed between crossed nicols are taken at various temperatures to observe the phase transition.