Nonlinear Optical Properties of Isomorphic Family of Crystals with Yttrium‐Aluminium Borate (YAB) Structure

Abstract The second harmonics generation of Nd‐laser radiation (λ = 1.06 microns) of the isomorphic family of crystals with yttrium‐aluminium borate (YAB) structure — RAl 3 (BO 3 ) 4 (R = Y, Sm, Eu, Gd, Dy, Er, Ho, Tu) — investigated using the powder method and the theoretical calculation of SHG–coefficients — are reported. The refraction indices (for λ = 5481 Å) and optical sign for all studied YAB‐type crystals are determined with the help of the immersion method. All studied crystals possess PM direction and oee‐interaction. The SH‐intensity is of KDP order of magnitude, with reasonable correlation of experimental and theoretical data. Theoretical analysis of the contributions of different ions to the integral d magnitude has shown identical signs for all ion species in YAB structure type.