Possibility to apply diffraction method to micro-shift measurements in linear dilatometry was researched. To creation diffraction pattern, the source of coherent radiation and narrow slot formed mobile half-plane rigidly connected with the investigated sample, and immobile half-plane was used. By multiple-unit photodetector, registration the diffraction pattern was realized. As typical points of diffraction pattern, the diffraction minimum was accepted. To increase the accuracy of an estimation of coordinates of minima, the polynomial approximation based method, as a most simple in realization of local signal approximation methods was offered. Results of micro-shift measurements and estimation of accuracy and reliability of the offered method are brought. The opportunity of registration of shifts in submicron range has been shown.

Keywords: Diffraction Method, Micro-Shift Measurements, Multiple-Unit Photodetector, Linear Dilatometry, Polynomial Approximation.