A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial...http://www.google.ca/patents/US6490307?utm_source=gb-gplus-sharePatent US6490307 - Method and procedure to automatically stabilize excimer laser output parameters
