The spectral phase of the femtosecond laser field is an important parameter that affects the upconversion (UC) luminescence efficiency of dopant lanthanide ions. In this work, we report an experimental study on controlling the UC luminescence efficiency in Sm³⁺:NaYF₄ glass by 800-nm femtosecond laser pulse shaping using spectral phase modulation. The optimal phase control strategy efficiently enhances or suppresses the UC luminescence intensity. Based on the laser-power dependence of the UC luminescence intensity and its comparison with the luminescence spectrum under direct 266-nm femtosecond laser irradiation, we propose herein an excitation model combining non-resonant two-photon absorption with resonance-mediated three-photon absorption to explain the experimental observations.

中文翻译：

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飞秒激光在Sm 3+：NaYF 4玻璃中的上转换发光的最佳光谱相位控制

飞秒激光场的光谱相位是影响掺杂镧系元素离子的上转换（UC）发光效率的重要参数。在这项工作中，我们报告了通过使用光谱相位调制通过800 nm飞秒激光脉冲整形来控制Sm ³⁺：NaYF ₄玻璃中UC发光效率的实验研究。最佳相位控制策略可有效增强或抑制UC发光强度。基于UC发光强度的激光功率依赖性及其与直接266 nm飞秒激光照射下的发光光谱的比较，我们在本文中提出了一种将非共振双光子吸收与共振介导的三光子吸收相结合的激发模型解释实验观察。