Saturation Spectroscopic Studies on Yb3+ and Er3+ Ions in Li6Y(BO3)3 Single Crystals

The results of a series of pump–probe spectral hole-burning experiments are presented on Yb3+- or Er3+-doped Li6Y(BO3)3 (LYB) single crystals in the temperature range of 2–14 K and 9–28 K, respectively. The spectral hole has a complex structure for Yb3+ with superposed narrow and broad bands, while a single absorption hole has been observed for Er3+. Population relaxation times (T1) at about 850 ± 60 μs and 1010 ± 50 μs and dipole relaxation times (T2) with values of 1100 ± 120 ns and 14.2 ± 0.3 ns have been obtained for the two components measured for the Yb3+:2F7/2—2F5/2 transition. T1 = 402 ± 8 μs and T2 = 11.9 ± 0.2 ns values have been found for the Er3+:4I15/2—4I11/2 excitation. The spectral diffusion rate at about 1 and 5 MHz/ms has been determined for the narrow and broad spectral line in Yb3+-doped crystal, respectively. The temperature dependence of the spectral hole halfwidth has also been investigated.