| 摘要 |
A current I i supplied to a pumping light source 20 is detected and time-averaged with a predetermined time constant to calculate a time-averaged current I av . An optical output power P i outputted from an amplifying optical fiber 12 is detected and time-averaged with the predetermined time constant to calculate a time-averaged optical output power P av . A reference optical output power P r and a reference current I r supplied to the pumping light source 20 when the reference optical output power P r is outputted from an optical fiber laser apparatus 1 are used to calculate an optical output power expectation value P ex = I av × P r / I r . The time-averaged optical output power P av and the optical output power expectation value P ex are compared with each other to determine a decrease of an optical output power of the optical amplifier apparatus 1 based on the comparison result. |
