Patent ID: 7245423

Claim:
A method for reducing noise in a fiber amplifier with respect to an optical signal of interest to be amplified by the fiber amplifier, comprising: a. generating a broad-band continuous wave incoherent optical signal having a bandwidth that is outside of the bandwidth of the optical signal of interest; b. combining the broad-band continuous wave incoherent optical signal with the optical signal of interest into a multi-mode optical fiber so that the broad-band continuous wave incoherent optical signal uniformly fills substantially an entire core of the multi-mode optical fiber; and c. amplifying the optical signal of interest and the broad-band continuous wave incoherent optical signal in the multi-mode optical fiber with the fiber amplifier, wherein the broad-band continuous wave incoherent optical signal increases generation of photos by stimulation so that as many photons as possible that are released from ions in the fiber amplifier are released by stimulation and not by spontaneous emission when a level of the optical signal of interest is very low or zero.