Eremeev Kirill, Loiko Pavel, Zhao Chengchun, Lin Zhang-Lang, Mateos Xavier, Zin Elabedine Ghassen, Camy Patrice, Braud Alain, Griebner Uwe, Petrov Valentin, Zhang Ge, Li Shanming, Hang Ying, Chen Weidong
Opt Express. 2024 Apr 8;32(8):13527-13542. doi: 10.1364/OE.518709.
We report on the growth, polarized spectroscopy and first laser operation of an orthorhombic (space group Pnma) Tm,Ho-codoped gadolinium orthoscandate (GdScO) perovskite-type crystal. A single crystal of 3.76 at.% Tm, 0.35 at.% Ho:GdScO was grown by the Czochralski method. Its polarized absorption and fluorescence properties were studied revealing a broadband emission around 2 µm. The parameters of the Tm ↔ Ho energy transfer was quantified, P = 1.30 × 10 cmµs, and P = 0.99 × 10 cmµs, and the thermal equilibrium lifetime was measured to be 3.5 ms. The crystal-field splitting of Tm and Ho multiplets in Cs symmetry sites of the perovskite structure was determined by low-temperature spectroscopy and the mechanism of spectral line broadening is discussed. The continuous-wave Tm,Ho:GdScO laser generated 1.16 W at ∼2.1 µm with a slope efficiency of 50.5%, a laser threshold of 184 mW, a linear laser polarization (E || c) and a spatially single-mode output. The Tm,Ho:GdScO crystal is promising for broadly tunable and femtosecond mode-locked lasers emitting above 2 µm.
我们报道了正交晶系（空间群Pnma）铥、钬共掺杂的钆钪酸盐（GdScO）钙钛矿型晶体的生长、偏振光谱及首次激光运转情况。采用提拉法生长了Tm含量为3.76原子百分比、Ho含量为0.35原子百分比的Ho:GdScO单晶。研究了其偏振吸收和荧光特性，发现其在2μm左右有宽带发射。对Tm↔Ho能量转移参数进行了量化，P = 1.30×10cmµs，P = 0.99×10cmµs，测得热平衡寿命为3.5ms。通过低温光谱确定了钙钛矿结构中Cs对称位点上Tm和Ho多重态的晶体场分裂，并讨论了谱线展宽机制。连续波Tm,Ho:GdScO激光器在~2.1μm处产生1.16W的功率，斜率效率为50.5%，激光阈值为184mW，具有线性激光偏振（E || c）和空间单模输出。Tm,Ho:GdScO晶体有望用于发射波长大于2μm的宽可调谐和飞秒锁模激光器。
