Increased efficiency of Er:YAG lasers at 1645 nm using narrow bandwidth diode lasers and dual-wavelength resonant pumping

Abstract

We demonstrate cw and Q-switched operation of Er:YAG laser systems emitting eye-safe radiation at 1645 nm. High brightness, narrow bandwidth diode laser modules at 1532 nm are used for resonant pumping, providing an absorption efficiency of 96%. Comparison with broadband diode pumping at 1455 nm shows an increase of the pumping efficiency by a factor of 2.5, leading to an optical efficiency of more than 25% in cw and 10 % in Q-switched mode under cw pumping. In addition, dual-wavelength resonant pumping of the Er:YAG laser is investigated.

Pure red upconverted and near‐infrared luminescence properties of Er3+‐doped SnO2 nanocrystals for lighting applications

“…The main peak is found at 1536 nm which corresponds to the 4 I 13/2 → 4 I 15/2 transition of Er 3+ . The occurrence of narrow peaks between 1450–1650 nm is due to the Stark splitting of the 4 I 13/2 → 4 I 15/2 transition of Er 3+ ions as shown in Figure 5b [38]. When the Er 3+ ions occupy the Sn 4+ site in the cassiterite structure, the ligand field around the Er 3+ ions lifts the degeneracy of the free ion J levels and splits into (2 J + 1)/2 Stark levels [39, 40].…”

All near-infrared multiparametric luminescence thermometry using Er3+, Yb3+-doped YAG nanoparticles

“…The obtained Δ E values are in good agreement with the energy separation between low and high energy 4 I 13/2 Stark levels. 52 …”