Ultra-low RIN fiber light source

An ultra-low RIN band fiber light source is provided. In one embodiment, the fiber light source includes at least one segment of optical fiber, one or more pump lasers, at least two wavelength division multiplexers and a reflective device. Each pump is adapted to output a power signal having a select wavelength and a select power level. Each wavelength division multiplexer is adapted to couple an associated power signal from at least one of the one or more pumps into the at least one segment of optical fiber to generate amplified spontaneous emission (ASE) signals having select parameters in the at least one segment of optical fiber. The reflective device is coupled to an end of the at least one segment of optical fiber and is adapted to reflect back a portion of the ASE signals.