Consideration of the Distribution of Noise Level by Wavelength in Broadband Control of the Optical Coating Deposition Process

Abstract

In the study, numerical results of simulations for the deposition process of a complex optical coating are presented, utilizing broadband monitoring of this process in the case where the noise level in the measured transmittance coefficient has a nonuniform distribution across the wavelength. The influence on the accuracy of control data at the edges of the measured wavelength range, where the error in the transmittance coefficient is maximal, is investigated. It is shown that the removal of some data at the edges of the range almost does not change the self-compensation factor of the errors in the deposition process, while the average norm of the error vector in the layer thicknesses significantly decreases. Thus, for the first time, it is demonstrated that taking into account the effect of error self-compensation in broadband control opens the possibility of a reasonable choice of the optimal spectral range for practical optical control.