Fiber laser light source apparatus

PROBLEM TO BE SOLVED: To provide a fiber laser light source device having high utilization efficiency of exciting light, and capable of oscillating laser light with high radiation intensity, even if it is compact.SOLUTION: A fiber laser light source device has a fiber laser constituted of an optical fiber emitting light of a wavelength different from that of the exciting light by receiving the exciting light, and resonators arranged on both end faces of the optical fiber. On the emission side end face of the fiber laser or the emission side end face of the optical fiber, an exciting light reflective film for reflecting the exciting light is formed.