Laser apparatus including plurality of laser modules

A laser apparatus comprising:

• a plurality of laser modules;
• a laser power source section configured to drive each of the plurality of laser modules;
• a combiner configured to combine laser beams emitted by the plurality of laser modules and to output a combined laser beam;
• an optical output command section configured to generate a first optical output command with respect to the combined laser beam;
• a laser module selection/command section configured to select a laser module to be driven from the plurality of laser modules, based on the first optical output command and to generate a second optical output command for the laser module that has been selected;
• and
• a control section configured to control the laser module and the laser power source section, based on the second optical output command,
• wherein, with respect to switching the number of laser-oscillating laser modules in accordance with a change in the first optical output command, the laser module selection/command section is configured to set a second threshold value for the first optical output command, when increasing the number of laser-oscillating laser modules to N, to a value higher or lower, by a predetermined value, than a first threshold value for the first optical output command serving as a reference, when reducing the number of laser-oscillating laser modules from N.