Experimental Study of Metrological Characteristics of the Automated Interferometric System for Measuring the Surface Shape of Diffusely Reflecting Objects

Abstract

The metrological characteristics of an automated interferometric system for measuring the surface shape of diffusely reflecting objects have been experimentally studied. Changes in the amplitude of the output signal during modulation of the optical path difference were studied and visualization of the effect of introduced interference on the measurement error was made. It is established that as the angle of incidence of optical radiation increases, the duration of the interference signal increases and, correspondingly, the measurement error of the automated interferometric system. The dependence of the measurement range on the scanning frequency of the reference mirror is obtained. The measurement error of an automated interferometric system under normal illumination does not exceed 0.67 μm.