Summary form only given. A low-cost, efficient fiber amplifier based on imbedded v-groove side-pumping of a double-cladding fiber was demonstrated. Side-pumping of double-cladding active fibers has the following advantages i) fiber ends are unobstructed and can be directly spliced to other fibers, ii) multiple v-grooves can be used to inject pump power at many points along the fiber, iii) no WDM couplers are required. These advantages yield a compact and efficient amplifier configuration and more than tenfold cost reduction. Improvements in the coupling efficiency and fiber slope efficiency, as well as the use of multiple v-grooves are expected to yield output powers well above the 154 mW demonstrated here.