A new method for determining the refractive index

A new method has been developed to determine the refractive index of a transparent material. The proposed method utilizes the optical method of transmitted caustics. The new method is simple, accurate and economical. Thin specimens with a central hole, loaded in tension, are used. The results obtained using this technique are compared with the available ones. The percentage difference between the optimum results obtained and the reported value is less than 5 percent. © 1997 Elsevier Science B.V