Optical amplifier with depolarized pump light

摘要

An optical Raman amplifier comprises a light source (29-34), a depolarizer (36), and a gain medium (16) that transfers energy from a pump beam output from the depolarizer to the optical signal (48) via stimulated Raman scattering. The depolarizer (36) may comprise one or more birefringent optical fibers which support two polarization modes, a fast mode and a slow mode. The light propagates in the fast mode at a higher velocity than the light propagates in the slow mode so as to impart phase delay as the light propagates in the birefringent optical fibers, thereby at least partially depolarizing the beam. <IMAGE>