Diffraction methods for monitoring the geometrical parameters and spatial position of objects

摘要

This paper discusses a diffraction method for monitoring the geometrical parameters and spatial position of objects. To enhance the sensitivity and the measurement accuracy and to broaden the functional possibilities of the method, it is proposed to use the phase resolution of the frequency spectra of the objects being monitored. In order to accomplish this, an information-processing optical system is implemented that successively carries out a Fourier transformation of the amplitude transmission function of the object and a Fresnel transformation of its frequency spectrum. An example is given of its use for angular measurements, and a technique is explained for calculating the design parameters of a diffraction autocollimator.