We report for the first time, to the best of our knowledge, an all-fiber Raman graded-index (GRIN) fiber laser pumped by a fiber laser. This configuration points to potential future power and brightness increases. Continuous-wave power of 135 W with an $M^2$ value of 2.5 was obtained at a wavelength of 1081 nm with an optical-to-optical efficiency of 68%. A commercial GRIN core fiber acts as the Raman fiber in a power oscillator configuration that includes fiber Bragg gratings (FBGs) written onto the GRIN fiber. The efficiency and brightness demonstrated here are, to the best of our knowledge, the highest reported in any Raman GRIN fiber laser. A brightness enhancement of the pump beam by a factor of 5.6 is attained due to the transverse profiles of Raman gain and FBG reflection in the GRIN fiber.

中文翻译：

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光纤激光器泵浦的高效全光纤连续波拉曼梯度折射率光纤激光器

据我们所知，我们首次报告了由光纤激光器泵浦的全光纤拉曼渐变指数（GRIN）光纤激光器。这种配置指出了潜在的未来功率和亮度增加。135 W的连续波功率${\mathrm{中号}}^{\mathrm{2个}}$在1081nm的波长处获得2.5的值，光-光效率为68％。商业GRIN芯光纤在功率振荡器配置中充当拉曼光纤，该功率振荡器配置包括写入GRIN光纤的光纤布拉格光栅（FBG）。据我们所知，此处展示的效率和亮度是所有拉曼GRIN光纤激光器中报告的最高效率。由于GRIN光纤中拉曼增益和FBG反射的横向轮廓，泵浦光束的亮度提高了5.6倍。