Abstract
The results from simulation of the structural and optical properties of YAG pure, doped with two ions and four ions of lanthanum, are presented in this paper to investigate the effect of dopants on a crystal. The simulation was carried out in the Quantum Espresso program. The band structure, density of states, the dielectric function, absorption, refractive index, energy loss function and reflectivity were calculated for different samples. It can be assumed that with a rise in concentration density of states, the impurity atom increases and the position of the most populated levels shifts to the right in the region of negative energies in the case of two atoms and to the left in the case of four atoms of lanthanum. We can draw conclusions about the transparency of the sample in the visible region, because the absorption spectra appear in the UV region. This transparent nature makes them perfect candidates for deep UV nonlinear optical materials. From the analysis of dielectric function, it is clear that in the case of YAG doped with two ions of lanthanum, two peaks appeared compared to the sample with one peak in pure and doped with four ions. Anisotropy is most pronounced with an increase in the degree of doping.