Upconversion‐pumped infrared erbium laser
Upconversion‐pumped infrared erbium laser
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DOI：
10.1063/1.337486
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发表时间：
1986-12
影响因子：
3.2
通讯作者：
S. Pollack;D. B. Chang;N. Moise
中科院分区：
文献类型：
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作者：
S. Pollack;D. B. Chang;N. Moise
对CaF 2中Er 3+离子的上转换过程的研究明确地证明了单独上转换泵浦产生的红外激光。研究表明：（1）来自4 I11/2态的强上转换谱线;（2）双光子和三光子上转换过程的存在;（3）Er 3+的最佳浓度为5-10 mol %;（4）可见波段的上转换效率在77 K时高达10%，在300 K时为1%。对4 I11/2和4 I13/2能级之间的激光发射的测量表明，即使上（4 I11/2）态的寿命只有下态的一半，也不会发生自猝灭。上转换与这种转变有关，既有激光脉冲期间“红移”的非持久性，也有激光阈值能量浓度和上转换产生的荧光强度的相反依赖性。一个简单的理论模型表明，工作在4 I11/2和4 I13/2能级之间的2.8 μm激光器可以单独由上变频泵浦。
A study of upconversion processes in Er3+ ions in CaF2 has led to an unambiguous demonstration of IR lasing produced by upconversion pumping alone. The study has shown: (1) strong upconversion lines originating from the 4I11/2 state; (2) the existence of both two‐photon and three‐photon upconversion processes; (3) an optimum concentration of 5–10 mol % for Er3+; and (4) upconversion efficiencies for the visible bands as high as 10% at 77 K and 1% at 300 K. Measurements of lasing between the 4I11/2 and 4I13/2 levels show that even though the lifetime of the upper (4I11/2) state is only half that of the lower state, self‐quenching does not occur. Upconversion is implicated for this transition both by the nonpersistence of a ‘‘red shift’’ during a lasing pulse, and by the opposite dependence on concentration of laser threshold energy and upconversion‐produced fluorescent intensity. A simple theoretical model shows that a 2.8‐μm laser operating between the 4I11/2 and 4I13/2 levels can be pumped solely by upco...