Patent ID: 7535628

Claim:
A laser light source comprising: a light source section outputting a first pulse laser light of a first wavelength having a first pulse period and a second pulse laser light of a second wavelength having a second pulse period, respectively; an optical amplification section for amplifying and outputting the first pulse laser light and the second pulse laser light being output from the light source section by means of a common optical amplification medium; an optical demultiplexing section for mutually demultiplexing the first pulse laser light and the second pulse laser light being output from the optical amplification section; an optical multiplexing section for multiplexing and outputting the first pulse laser light and the second pulse laser light being demultiplexed in the optical demultiplexing section; and an optical path length difference setting section for setting an optical path length difference between a first optical path for the first pulse laser light and a second optical path for the second pulse laser light between the optical demultiplexing section and the optical multiplexing section; wherein the optical path length difference setting section comprises a variable optical-path length difference adjusting section by which an adjustment amount of the optical path length difference is variable.