Properties of the APE waveguides fabricated in Er:LiNbO3 and (Er+Yb):LiNbO3

We present a study of the annealed proton exchanged waveguides fabricated in erbium and in a mixture of erbium and ytterbium (RE) bulk doped lithium niobate. Waveguiding properties and composition of the RE doped waveguides were not substantially changed compared with those fabricated in pristine lithium niobate. However, presence of the doping ions decreases the r 33 , but a carefully designed APE technology can increase the r 33 almost to the value of the pristine LiNbO 3 . According to our results the proton exchange need not necessarily change the efficiency of the 1,5 μm emission and certainly does not lower the concentrations of the RE.