2ND-HARMONIC GENERATION AT THE SURFACE OF CUBIC IONIC-CRYSTALS

The strength of the different source terms in the isotropic Second Har monic (SH) response of the surface has been measured in different ioni c crystals LiF, NaF, GGG(Gadolinium-Gallium-Garnet), and MgF2, using a s excitation beam the fundamental output of a Nd:YAG laser (1.06 mum). The azimuthal dependences of the optical second-harmonic generation h as also been measured at the LiF(100), LiF(111), GGG(100), and GGG(111 ) surfaces. No experimental evidence of a bulk contribution to the ani sotropic part of the nonlineau polarization has been observed.