Patent ID: 9246297
Filing Date: 2016-01-26
CPC Classification: H01S

Claim Text:
1. A gas laser oscillator comprising a plurality of discharge tubes through which a laser gas circulates, a plurality of main discharge electrodes which are arranged corresponding to the plurality of discharge tubes and which make main discharge start for discharge excitation of said laser gas, a plurality of auxiliary electrodes which are arranged adjoining the plurality of main discharge electrodes and which make auxiliary discharge start in said laser gas in a state lower than the output by which said main discharge starts, an output mirror which outputs a laser which is oscillated at said plurality of discharge tubes, and a mechanical shutter which cuts off the laser output from the output mirror, wherein a base command for maintaining said auxiliary discharge in the state where the laser output is zero is set to a first command value when said mechanical shutter is closed, and is set to a second command value smaller than said first command value when said mechanical shutter is opened.