Sheng Quan, Li Ran, Lee Andrew J, Spence David J, Pask Helen M
Opt Express. 2019 Mar 18;27(6):8540-8553. doi: 10.1364/OE.27.008540.
A continuous-wave (CW) single-longitudinal-mode (SLM) intracavity Raman laser is demonstrated for the first time, by virtue of the spatial hole-burning free nature of stimulated Raman scattering (SRS) gain. By using a single etalon in the Nd:GdVO fundamental laser cavity, the spectral linewidth of the multimode fundamental field is suppressed below the Raman linewidth of Raman crystal BaWO; hence power in all the longitudinal modes of fundamental field can be extracted by one single Stokes mode. Therefore, the hole-burning free SRS gain exhibits a spectral cleanup effect whereby a stable SLM Stokes field is derived from the multimode fundamental field within a simple standing-wave cavity arrangement. The low-threshold SLM Raman laser delivered 3.42 W SLM Stokes and 1.53 W SLM one-way yellow harmonic at the guide-star wavelength of 589.16 nm. The results here provide a new approach to SLM laser operation with good simplicity and power dynamic range. Further engineering for power scaling and better stability is also discussed.
首次展示了一种连续波（CW）单纵模（SLM）腔内拉曼激光器，这得益于受激拉曼散射（SRS）增益的无空间烧孔特性。通过在Nd:GdVO基频激光腔中使用单个标准具，多模基频场的谱线宽度被抑制到低于拉曼晶体BaWO₄的拉曼线宽；因此，基频场所有纵模的功率都可以被一个单斯托克斯模提取。所以，无空间烧孔的SRS增益呈现出一种光谱净化效应，借此在一个简单的驻波腔结构内从多模基频场中获得稳定的单纵模斯托克斯场。低阈值单纵模拉曼激光器在589.16 nm的导星波长处输出了3.42 W的单纵模斯托克斯光和1.53 W的单纵模单向黄色谐波光。此处的结果为单纵模激光运行提供了一种兼具良好简单性和功率动态范围的新方法。还讨论了功率缩放和更好稳定性的进一步工程设计。
