Strong nonlinear optical response in epitaxial liftoff single-crystal LiNbO3 films

We report on optical frequency mixing in epitaxial liftoff thin films of si ngle-crystal LiNbO3 integrated onto heterogeneous planar glass platforms. T hese films are found to have a nonlinear optical response comparable to tha t of the bulk. Second-harmonic generation is investigated as a function of crystal orientation, ion implantation, and modal and temperature dispersion . Ion implantation-induced shifts in the refractive indices are shown to be useful for achieving phase matching. (C) 1999 American Institute of Physic s. [S0003-6951(99)02445-6].