Infrared emission properties and energy transfer between Tm^3+ and Ho^3+ in lanthanum aluminum germanate glasses

Abstract

Tm3+∕Ho3+ codoped lanthanum aluminum germanate glasses are prepared by a simple melt-quenching method. The 2 μm 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.