Measurement of the deuterium concentration profile in a deuterium- exchanged LiNbO(3) crystal.

We have measured the concentration of deuterium as a function of depth in a deuterium exchanged LiNbO(3) sample using nuclear reaction analysis. From the shape of the concentration profile we calculate the concentration dependent effective diffusion coefficient for deuterium-lithium counterdiffusion. Comparison of the concentration and refractive index profiles for this waveguide confirms that the index increase in exchanged material is a nonlinear function of concentration. We discuss implications of these results for optical waveguide fabrication.