3 kW Passive-Gain-Enabled Metalized Raman Fiber Amplifier With Brightness Enhancement

Raman fiber lasers (RFLs) are currently promising and versatile light sources for a variety of applications. So far, operations high power brightness-enhanced RFLs have absorbed enormous interests along with rapid progress. Nevertheless, the stable lasing at levels remains challenged by thermal effects. In an effort to realize more effective management in RFLs, here we demonstrate first time, all-fiberized amplifier (RFA) based on metal-coated passive enabling lasing. By employing aluminum coating graded-index (GRIN) fiber, dissipation is sufficient support low-temperature but high-power operation. The maximum output reaches 3.083 kW 1130 nm conversion efficiency 78.7%. To best our knowledge, this highest attained fields merely nonlinear gain. Stokes emission GRIN enables brightness enhancement (BE) laser. Accordingly, beam quality parameter M 2 BE value 3.12 ~9 when signal 2.364 kW, which reach 5.72 ~2.9 power, respectively. As far as know, achieved record among all any kind configurations.