Novel, High-Power, Pump-Signal Fiber Combiner

Recent advances in fiber lasers have shown their potential for power scaling to Directed Energy levels. Many of the high-power, cladding-pumped, large-mode-area fiber systems demonstrated in the laboratory have employed free-space optics to couple the diode laser pump power into the pump cladding of the fiber. While the approach is useful for power scaling demonstrations, it is not practical for operational lasers in terms of both reliability and ruggedness. High power, all-fiber pump combiners replace free-space optics for pump insertion and allow construction of"all-glass"fiber lasers. In the Phase I work proposed here we plan to fabricate a prototype of the only, to the best of our knowledge, end-pumped combiner configuration that allows almost any signal fiber to be used, including the same signal fiber used in the laser.