Electro-optic and nonlinear optical properties of ion implanted waveguides in organic crystals.

We report on the electro-optic and nonlinear optical properties of waveguides produced by low fluence (Phi = 1.25x10(14) ions/cm(2)) H+ ion implantation in the organic nonlinear optic crystal 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium tosylate (DAST). The profile of the nonlinear optical susceptibility has been determined by measuring the reflected second-harmonic generation efficiency from a wedged-polished sample at a fundamental wavelength of lambda(omega) = 1176nm. In the waveguide core region the nonlinear optical susceptibility is shown to be preserved to more than 90% of its bulk value. A model which relates the molecular changes to the measured macroscopic alteration of the refractive index and the nonlinear coefficient has been introduced to quantify the fraction of molecules modified by ion implantation. Furthermore, a first electro-optic modulation in ion implanted DAST waveguides has been demonstrated.