Patent ID: 8761225

Claim:
A laser apparatus comprising: a laser medium; a resonator including mirrors, with said laser medium interposed between said mirrors; an excitation unit configured to irradiate said laser medium with excitation light for exciting said laser medium; a beam splitter disposed outside said resonator and configured to split laser light emitted from said resonator; a light detector disposed outside the resonator and configured to detect a portion of the laser light split by said beam splitter; a light-shielding unit disposed outside said resonator and arranged to block another portion of the laser light, wherein the portion of the laser light being a portion that has been split off by the beam splitter and is not detected by said light detector; and a control unit configured to select a light irradiation state, and a light-shielding state in which said light-shielding unit is arranged to block more of the laser light emitted from said resonator as compared with the light irradiation state, wherein, in the light-shielding state, said excitation unit irradiates the excitation light so as to reduce consumption of said excitation unit as compared with the light irradiation state under control of a setting value, and wherein said control unit is configured to control the setting value based on an output from said light detector in the light shielding state.