Patent ID: 8649403

Claim:
A fiber laser device comprising: a seed laser light source configured to output seed laser light; a pumping light source configured to output pumping light; an amplification optical fiber configured to receive the seed laser light and the pumping light, amplify the seed laser light, and output the seed laser light as laser light, the amplification optical fiber being doped with a rare-earth element, the rare-earth element being pumped by the pumping light; an output unit configured to output the laser light output from the amplification optical fiber; a control unit configured to control at least the seed laser light source and the pumping light source, and control an intensity of the pumping light output from the pumping light source; and an output instructing unit configured to input an output instruction to the control unit, the output instruction causing the output unit to output the laser light, wherein, when the output instruction is input to the control unit, the control unit controls the seed laser light source and the pumping light source to initiate a pre-pumped state and switch from the pre-pumped state to an output state, and the control unit calculates a duration of time between an end time of a previous output state and the time when the output instruction is input to the control unit, wherein in the pre-pumped state, the seed laser light source does not output the seed laser light while the pumping light source outputs the pumping light for a predetermined period of time, in the output state, the seed laser light source outputs the seed laser light, and the pumping light source outputs the pumping light, to cause the output unit to output the laser light, and wherein in the pre-pumped state, the control unit sets the intensity of the pumping light output from the pumping light source according to the calculated duration of time.