Control of electromagnetically induced grating by Er3+ ion concentration in an Er3+ -doped YAG crystal

We investigate the effect of doped ${{\rm Er}^{3 +}}$ ion concentration on an electromagnetically induced grating in an ${{\rm Er}^{3 +}}$-doped yttrium aluminum garnet (YAG) crystal. Due to the change of electric dipole moment and spontaneous emission decay induced by ${{\rm Er}^{3 +}}$ ion concentration, the Fraunhofer diffraction of the solid-state grating is sensitively dependent upon ${{\rm Er}^{3 +}}$ ion concentration. The three-level ${{\rm Er}^{3 +}}$ ion system with a closed loop leads to probe gain appearing in some concentrations of the ${{\rm Er}^{3 +}}$ ion, which significantly improves the first-order diffraction efficiency of the solid-state grating. Furthermore, it is demonstrated that the relative phase, signal detuning, and grating thickness have different effects on the first-order diffraction efficiency of the solid-state grating under different concentrations of the ${{\rm Er}^{3 +}}$ ion. Therefore, our scheme may provide a basis for selecting a suitable concentration to realize high-efficiency optical switching and routing in future integrated systems.