US Patent 7336415 Optical amplification module, optical amplification apparatus, and optical communications system

The present invention relates to a practical optical amplification module and the like realizing a wide-band gain spectrum with a small relative gain non-uniformity in L band. Pumping light from a pumping light source is supplied to a Bi type EDF by way of an optical coupler. Multiplexed signal light of L band inputted by way of an input end reaches the Bi type EDF by way of an optical coupler, an optical isolator, and an optical coupler, and is collectively amplified in the Bi type EDF. The multiplexed signal light amplified in the Bi type EDF is outputted from an output end by way of an optical coupler, an optical isolator, and an optical coupler.