A low-noise, high-gain optical image amplifier includes a multi-mode pump source that injects optical energy into an active fiber's inner cladding to excite the dopant ions in a 2-D array of doped cores and provide gain. The cores are arranged to sample and collect light from an image incident on one end of the fiber, amplify the light and output an amplified pixilated image at the other end of the fiber. The multi-core active fiber preserves the spatial pattern and spectrum of the incident image. The cores may be configured as single-mode cores to preserve phase information or multi-mode cores to scramble the phase information. It is often desirable for the gain to be approximately uniform across the 2-D array. This can be achieved by pumping uniformly doped cores into their respective saturation regions.