Luminescence from the 3P2 state of Tm3+

Abstract

Using various ultraviolet laser excitation lines between 199.8 nm (50 034 cm -1) and 266 nm (37 583 cm -1), emission transitions have been observed and assigned for the first time from the 3P 2 term of Tm 3+, located near 37 500 cm -1. The most intense transitions are to the terminal 3H 6 and 3F 4 states, and are almost entirely vibronic in character for Tm 3+ in elpasolite cubic lattices. In other systems, these transitions may find application in ultraviolet lasers. The interpretation of the 3P 2 → 3H 4 emission transition in Cs 2NaTmCl 6 reveals electron-phonon coupling phenomena analogous to that in the 3H 6 ground state, and which provides the explanation for the enormous deviation between the experimental and calculated energy of the 3H 4 Γ 4 level. We also report the quantum cutting of blue to infrared radiation in Cs 2LiTmCl 6 and the upconversion from 1D 2 to 3P 2 in Cs 2NaTmCl 6.