METHOD FOR DETERMINING THICKNESS OF LAYERS OF MULTILAYER COATING IN PROCESS FOR DEPOSITION OF OPTICAL ELEMENTS Russian patent published in 2018 - IPC G01B11/06 

FIELD: optics; technological processes.

SUBSTANCE: invention relates to installations for vacuum deposition of multilayer coatings of various optical elements and can be used to control the thickness of coatings in a wide spectral range during their deposition. Method for determining the thickness of the layers includes calculating the thicknesses of the layers to obtain the desired reflectance or transmission of the coating in the spectral range, calculating the optical thickness of each layer and measuring the reflection or transmission spectrum of the coating layers with the calculated optical thicknesses applied to the reference substrates simultaneously with the optical elements. In addition, the spectra of reflection or transmission of the coating structure from 2, 3, …, N layers applied to the control imitation substrate, the physical thickness of each layer is measured with quartz microbalances, by the values of optical and physical thickness determine the actual refractive indices of the materials to be sprayed and their deviation from the thicknesses used in the calculation of the layers. After the deposition of any layer, the resulting reflection or transmission spectra on the imitation substrate are measured, compared with the corresponding calculated spectra of the coating structure and by their deviation determine the amount of thickness adjustment of the subsequent layer or deposition modes using the established actual refractive index.

EFFECT: increased accuracy of determining the optical thickness of the coating layers.

1 cl, 1 dwg