Measurement of Refractive Index of Liquids by the Maximum and Minimum Deviated Laser Beam

The prism spectrometer is a standard device for the measurement of refractive index; it is used in undergraduate laboratories. Typically, however, lots of attention is required in the alignment, and the accuracy of the obtained refractive index is not so high in spite of the durability of the device. The maximum and minimum deviation method, which compensates the disadvantages of the prism spectrometer, can be composed cost effectively using a length marking tape and a rotating platform. It can measure the refractive indices accurately by utilizing a wide screen. In this study, the equal sided hollow prism whose length is 26 mm was fabricated and measured the refractive indices of seven kind of liquids ( pure water, C3H5(OH)(2), CCl4, C6H4NH2, CS2, C6H4(CH3)(2)) by using the prism spectrometer and maximum and minimum deviated laser beam method at the wavelengths of He-Ne laser (lambda - 632.8 nm) and YVO4 laser (lambda - 532 nm). The result shows that the data obtained by the latter method are more accurate and precise than those obtained by the former device.