Improved High-Power Pump Couplers Navy SBIR FY2009.1 Sol No.: Navy SBIR FY2009.1 Topic No.: N091-015 Topic Title: Improved High-Power Pump Couplers Proposal No.: N091-015-1253 Firm: Q Peak, Inc. 135 South Road Bedford, Massachusetts 01730 Contact: Glen Rines Phone: (781) 275-9535 Web Site: www.qpeak.com Abstract: Recent advances in fiber lasers have shown their potential for power scaling to Directed Energy (DE) levels. Many of the high-power, cladding-pumped, large-mode-area (LMA) 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. In the work proposed here, we plan to develop and test high-power, all-fiber pump combiners to replace free-space optics for pump transport and allow construction of "all-glass" fiber lasers. The pump couplers must be compatible with polarization-maintaining (PM) LMA fibers used in the beam-combined systems needed to generate DE power levels. Also, given the interest, for some applications, in "eyesafer" DE systems, the couplers should work with not only Yb-doped fibers, but also with Tm-doped, 2-micron-wavelength fibers. Benefits: The evident advantages of the pump couplers in facilitating all-glass fiber lasers for fieldable, reliable and efficient directed-energy systems should warrant further support by the Navy and other DoD agencies in Phase III programs and beyond. In terms of other applications, high-power fiber lasers are of interest for materials processing, and can also be employed in coherent lidar/ladar systems, which have uses for Government, scientific and commercial customers in areas such as wind-sensing, target ID and tracking, and vibration sensing. Another application is in IR countermeasures, where the efficiency and reliability would be a major advance over current technology. Return