Search for: [Abstrakt = "The paper is focused on measurement techniques of gradient\-index elements particularly useful for slightly inhomogeneous glasses from small laboratory melts. A construction of the measurement cuvette and dependence of the refractive index of an immersion liquid on its parameters is discussed. The dependence of the refractive index of α\-bromonaphtalene on temperature for λ = 0.6328 μm is described. A measuring method of the refractive index profile of gradient\-index elements is presented."]