Investigations of a new class of optical materials with functional nonuniform distribution of optical dopant are continued. Longitudinal pumping and heat release in active elements with a gradient...

The luminescent properties of gradient-activated crystals of lithium niobate with concentration profiles of optical centers, ytterbium and erbium ions, are studied. It is shown that the spectral-luminescent properties of the gradient crystals are correlated with the concentration profiles of optical centers — donors Yb³⁺ and acceptors Er³⁺.

The broadband luminescence of chromium optical centers with strongly overlapping spectral lines and similar emission probabilities from excited ⁴ T ₂ states of red and green Cr³⁺ centers in stoichiometric magnesium-doped lithium niobate crystals has been separated for the first time. The spectral-luminescence characteristics and parameters of intracenter interaction between red and green optical Cr³⁺ centers in stoichiometric lithium niobate have been calculated. The luminescence quantum efficiencies of red and green chromium centers are determined.