a1 Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China; and Key Laboratory of Optoelectronics Information and Technology (Tianjin University), Ministry of Education, Tianjin, 300072, People’s Republic of China
a2 Department of Applied Physics-I3A, Universidad de Zaragoza, 50009 Zaragoza, Spain
a3 Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong, People’s Republic of China
We have measured at room temperature polarized visible and near-infrared and unpolarized mid-infrared (2.7 μm) emission spectra of Er3+ in LiNbO3 (LN) crystals grown from congruent melts doped with 0.0/0.5, 0.5/0.5, and 1.0/0.5 mol%/mol% In2O3/Er2O3. From the measured emission spectra, the emission and absorption cross section spectral distributions were analyzed based on McCumber theory and discussed in comparison with those spectra of only Er-doped LN bulk material and/or Ti: Er: LN waveguide structure and with the results from the unpolarized absorption measurements. For the 530 and 1530 nm transitions, the cross section value, polarization dependence, and spectral shape all change from the only Er-doped material to the In–Er-codoped crystal and show definite In2O3 doping level effect. The 559, 673, 996, and 1530 nm emission lifetimes were also measured and used to evaluate nonradiative multiphonon relaxation rate. The calculated radiative, measured lifetimes, and multiphonon relaxation rate also show In-codoping effects.
(Received December 10 2010)
(Accepted February 11 2011)
(Online publication April 27 2011)