Nufern's 25/250 Ytterbium-doped double clad fiber is ideally suited for high peak power pulsed fiber amplifier applications. Based on a waveguide structure that supports less modes than the 30/250 fiber, this fiber is incorporated into components and monolithic designs where maintaining beam quality can be more difficult. Both non-PM and PANDA-style PM fibers are available, as are a range of support fibers for component and pigtail development efforts. As with all Nufern standard Large Mode Area (LMA) fibers, these fibers are proof-tested to 100 kpsi, an industry requirement for long term reliability when coiling for mode filtering.