Laser oscillator apparatus and power supply apparatus therefor, and control method therefor

A power supply apparatus for use in a laser oscillator apparatus that compares a desired laser output power command value with a measured output power value of a laser beam emitted from the laser oscillator apparatus, and that provides a feed-back control of a current to be supplied to pumping means that pumps a laser medium so that a laser output power corresponding to the laser output power command value is obtained, the power supply apparatus comprising:

• current measuring means that measures a value of the current supplied to the pumping means;
• upper limit current value determination means that determines an upper limit current value based on a laser output power command value that is to be input separately;
• command current value determination means that determines, as a command current value, a value of the current to be supplied to the pumping means, according to a difference between the laser output power command value and the measured output power value of the laser beam;
• a comparator that compares the command current value with the upper limit current value, to output the smaller value thereof as a reference current value;
• and
• current limiting means that compares the reference current value with the measured current value, to limit a value of the current supplied to the pumping means so that the value of the current is controlled to be the reference current value.

A method of controlling a laser oscillator apparatus that emits a laser beam by supplying laser-medium-pumping means with a current, the method comprising the steps of:

• measuring a value of the current supplied to the pumping means;
• measuring an output power of a laser beam to be emitted from a laser oscillator apparatus;
• determining an upper limit current value based on a desired laser output power command value;
• determining, as a command current value, a value of the current to be supplied to the pumping means, according to a difference between the laser output power command value and the measured output power value of the laser beam;
• comparing the command current value with the upper limit current value, to determine the smaller value thereof as a reference current value;
• and
• comparing the reference current value and the measured current value, to limit a value of the current supplied to the pumping means so that the value of the current is controlled to be the reference current value.