Observation of ESA, ET and thermally enhanced frequency upconversion in Nd3+: LiTeO2 glassK. Kumar, D. K. Rai and S. B. RaiEur. Phys. J. Appl. Phys., 41 2 (2008) 143-149DOI: https://doi.org/10.1051/epjap:2008008
