Patent ID: 7551661

Claim:
A gas laser oscillator that excites a laser gas to generate laser light, comprising: a circulation path for the laser gas; a circulation means for circulating the laser gas through the circulation path; a pressure detection means for detecting the pressure of the laser gas in the circulation path; an electric power detection means for detecting electric power to drive the circulation means; a storage means for storing the relationship between the pressure of the laser gas and the electric power of the circulation means during the period of normal operation of the circulation means for each kind of the laser gas; and a laser gas determination means for determining the kind of the laser gas based on the pressure of the laser gas and the electric power of the circulation means detected respectively by the pressure detection means and the electric power detection means during the period of normal operation of the circulation means, and the relationship between the pressure of the laser gas and the electric power of the circulation means stored in the storage means.