Cascade co-pumping — A new way of efficient pumping of high-power rare-earth co-doped fiber lasers and amplifiers

In this paper, a new efficient pumping scheme was proposed for high-power rare-earth co-doped fiber lasers and amplifiers. We show by numerical simulations that by introducing a resonant cavity oscillating in the sensitizer's emission band can effectively convert the cladding-pump to a more efficient core-pump. This method greatly helps to suppress the amplified spontaneous emission in the sensitizer's band, increase the efficiency, and reduce the gain fiber length.