Proton-exchanged LiNbO(3) waveguides: relevance of atmospheric environment during annealing

The relevance of the type of atmosphere used during the annealing of proton-exchanged LiNbO(3) planar waveguides is discussed. The experimental evidence, based on a comparison of the refractive-index profiles of waveguides annealed under wet O(2), dry O(2), or ambient atmospheres, with various gas flow rates, suggests that the atmosphere type does not influence the properties of the resulting waveguide.