Experimental and theoretical analysis of leaky extraordinary modes in negative uniaxial channel waveguides

We perform a theoretical and experimental study of the radiation losses of extraordinary-like leaky modes in negative uniaxial waveguides, such as Ti:LiNbO3 channel waveguides, with the axis inclined to the optical axis. Different waveguides have been realized and characterized varying some fabrication parameters. The numerical model utilized is based on the assumpton that the leaking power is radiated only by the ordinary substrate field. The comparison between experimental data and numerical results obtained with this assumption confirms the validity of the approach.