Characterisation of LiNbO3:Er/Yb Waveguides

Among the optoelectronic devices developed based in rare-earth doped LiNbO3 crystals, the Erbium doped LiNbO3 laser has shown excellent performances [1] becoming the starting point of advanced integrated devices. A limitation in its performances arises from the relatively low absorption cross section in the laser diodes emission range, which limits the pump efficiency. One possible way of improvement, which has been succesfully implemented in other materials, consists on the use of Yb as codopant. Ytterbium not only has a high absorption cross section in the InGaAs emission range but it has also a broad absorption band that offers the possibility of excitation tunning in the 875-1000 nm wavelength region. The great overlap between ytterbium emission and erbium absorption bands allows efficient energy transfer from Yb3+ to Er3+.