| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical circuit device in which the cause of decrease in output from an optical fiber for amplification can be understood by an inexpensive configuration.SOLUTION: A fiber laser device 1 includes excitation light sources 20A, 20B for supplying exciting light, and an optical fiber 12 for amplification. A first rare earth element (Yb) emitting laser oscillation light by receiving the exciting light, and a second rare earth element (Er) emitting the monitor light having a wavelength different from that of the laser oscillation light are added to the optical fiber 12 for amplification. The fiber laser device 1 further includes a light separator 40 for separating the laser oscillation light from the light passed through the optical fiber 12 for amplification, a photo-detector 42 for detecting the intensity of the laser oscillation light, a light separator 60 for separating the monitor light from the light passed through the optical fiber 12 for amplification, a photo-detector 62 for detecting the intensity of the monitor light, and a photo-darkening detection unit 70 for detecting the photo-darkening by comparing a change in the intensity of laser oscillation light with a change in the intensity of monitor light. |
