Crystalline phase, profile characteristics and spectroscopic properties of Er3+/Tm3+-diffusion-codoped LiNbO3 crystal

Er3+/Tm3+-codoped LiNbO3 crystal was prepared by co-diffusion of stacked Er and Tm metal films. The crystalline phase, diffusion profile and cross section spectra of Er3+ and Tm3+ ions in the diffusion layer have been investigated. The results show that the presence of Er3+ and Tm3+ ions is in the LiNbO3 phase. Both ions follow Gaussian profile with a diffusion depth 21.5 μm. Both ions keep their respective spectroscopic features of only doping case. Excited state absorption is the dominant process for 795-nm-upconvered fluorescence of Tm3+. The codoping enables to combine the wavelength emissions of both ions and provide the possibility of S+C+L broadband amplification. Er3+/Tm3+-codoped LiNbO3 is a promising material for integrated optics.268