Infrared emission properties and energy transfer between Tm3+ and Ho3+ in lanthanum aluminum germanate glasses

Tm3+/Ho3+ codoped lanthanum aluminum germanate glasses are prepared by a simple melt-quenching method. The 2 mu m emission characteristic and energy transfer from Tm3+ to Ho3+ upon excitation of a conventional 808 nm laser diode is investigated. The spectroscopic properties are estimated by using Judd-Ofelt parameters, branching ratios, and lifetimes. The microscopic energy transfer parameters of each process are also calculated. The large energy transfer coefficient of Tm3+ to Ho3+ and the little back energy transfer from Ho3+ to Tm3+ indicate that an efficient energy transfer process occurs. (C) 2010 Optical Society of America