Characterization of Er3+-doped Ti:LiNbO3 waveguides: losses, absorption spectra and near field measurements

In this paper we present some experimental results about the characterization of Er^3+-doped Ti:LiNbO_3 waveguides using nondestructive methods. We report results concerning losses, near field and absorption measurements. Waveguide losses have been measured in the 1550 nm wavelength region through an interferometric method based on two different techniques: thermal cavity tuning and wavelength sweeping. Homogeneous absorption and emission cross sections have been calculated from transmitted spectra. The near field measurements have been used to obtain the waveguide mode profile through a deconvolution algorithm to eliminate the probe effect. The resulting field profile allowed to reconstruct the refractive index distribution