Using the moiré effect to increase the accuracy of diffraction methods for monitoring the geometrical parameters and the spatial position of objects

Назаров В.Н., Иванов А.Н. Использование явления муара для увеличения точности дифракционных методов контроля геометрических параметров и пространственного положения объектов // Оптический журнал. 2009. Т. 76. № 1. С. 46–50.

Nazarov V.N., Ivanov A.N. Using the moiré effect to increase the accuracy of diffraction methods for monitoring the geometrical parameters and the spatial position of objects [in Russian] // Opticheskii Zhurnal. 2009. V. 76. № 1. P. 46–50.

V. N. Nazarov and A. N. Ivanov, "Using the moiré effect to increase the accuracy of diffraction methods for monitoring the geometrical parameters and the spatial position of objects," Journal of Optical Technology. 76 (1), 39-42 (2009). https://doi.org/10.1364/JOT.76.000039

This paper discusses a diffraction method of monitoring that makes it possible to use a measurement signal's phase component that carries data concerning the geometrical shape and spatial position of an object. To increase the measurement accuracy and sensitivity, a data-processing optical system was implemented in which the test object is illuminated by two beams of coherent radiation displaced in space. This made it possible to introduce a phase shift between their frequency spectra while varying the parameters of the object and to obtain moiré interference fringes in the recording plane, by analyzing which data can be obtained concerning the test object. An example is given of the use of the method to investigate the shape of the edge profile of an object.