A polarization-diverse optical amplifier includes a polarization-sensitive optically active medium and a polarization splitter. The polarization splitter is configured to receive input light, to direct a first polarization component of the received input light to a first optical path segment, and to direct a second polarization component of the received input light to a separate second optical path segment. The active medium has first and second optical ports. The first optical port is at an end of the first optical path segment. The second port is at an end of the second optical path segment. The active medium outputs amplified light from one of the ports in response to receiving the input light at the other of the ports. In a preferred embodiment, the active medium has an internal optical axis, and the polarizations of the first and second components are oriented relative to that axis so that amplification is enhanced. The two optical path segments may include polarization-maintaining optical waveguides.