OPTICAL AMPLIFICATION MODULE AND LASER LIGHT SOURCE DEVICE

PROBLEM TO BE SOLVED: To achieve effective suppression of photo-darkening and effective optical amplification in an optical amplification module.SOLUTION: An optical amplification module 3A comprises: a first optical amplification waveguide 41 including a first optical waveguide region having a Yb element added thereto; a second optical amplification waveguide 43 optically coupled to the first optical amplification waveguide and including a second optical waveguide region having a Yb element co-doped with an Al element added thereto; and excitation light sources 21 and 23 for supplying excitation light to each of the first optical amplification waveguide 41 and the second optical amplification waveguide 43. The light subject to amplification is amplified only once by using the excitation light in the first optical amplification waveguide 41 and the second optical amplification waveguide 43.