An improved device and method to pump fiber lasers in order to enhance performance and reliability is provided. A fiber laser is bent into a coil having a moderate curvature so as to avoid radiation losses. A cladding is partly polished to produce coupling surfaces along the length of the spring-like coil. Radiation emitters are imaged with one or more micro lenses that are attached to the coupling surface. In a preferred embodiment, banks of high power laser diodes are utilized as pump sources. Coupling surfaces are preferably created along the length of the fiber at intervals where pump radiation from the previous pump edge has been absorbed. Although the system may be used to pump single mode fibers, the preferred application is to pump multimode fibers, having greater core diameters and higher luminescent capacity, wherein only a single cladding can be used. When a core dopant is included that can convert infrared to visible wavelengths, the device is particularly useful as a light source for homogeneously illuminated and partially illuminated fibers that diffuse light along their lengths.