Bannerman Rex H S, Smith Devin H, Gray Alan C, Gates James C, Broderick Neil G R, Gawith Corin B E, Smith Peter G R
Opt Express. 2022 Apr 11;30(8):12427-12439. doi: 10.1364/OE.445876.
We demonstrate that the stimulated Brillouin scattering of a 250 mm long distributed feedback Raman fiber laser can self-pulse with repetition rates up to 7 MHz, pulse widths of 25 ns, and peak powers of 1.2 W. While both CW and pulsed lasing are produced from a bespoke grating at 1119 nm this laser design could be constructed at almost any wavelength, as the Raman and Brillouin gain regions are relative to the pump wavelength. The laser has a low lasing threshold for a Raman laser of 0.55 W, a peak slope efficiency of 14 %, and a maximum average output of 0.25 W. An investigation of beating between pure Raman and Raman-pumped Brillouin lasing shows that the outputs of the two processes are highly correlated and thus the Brillouin lasing is essentially single-frequency when CW and near transform limited for pulsed operation. A phenomenological model of the Raman-Brillouin interaction shows that the pulsing behaviour of such a cavity is expected and produces very similar pulsing to that the seen in experimental results.
我们证明，250毫米长的分布反馈拉曼光纤激光器的受激布里渊散射能够以高达7兆赫兹的重复频率、25纳秒的脉冲宽度和1.2瓦的峰值功率进行自脉冲发射。虽然连续波（CW）和脉冲激光都是由定制的1119纳米光栅产生的，但由于拉曼增益区和布里渊增益区相对于泵浦波长，这种激光设计几乎可以在任何波长下构建。该激光器对于拉曼激光器而言具有较低的激射阈值，为0.55瓦，峰值斜率效率为14%，最大平均输出为0.25瓦。对纯拉曼激光与拉曼泵浦布里渊激光之间的拍频研究表明，这两个过程的输出高度相关，因此在连续波模式下，布里渊激光基本为单频，在脉冲工作时接近变换极限。拉曼 - 布里渊相互作用的唯象模型表明，这种腔的脉冲行为是预期的，并且产生的脉冲与实验结果中观察到的非常相似。
