Patent ID: 6249535
Filing Date: 2001-06-19
Classification: H01S

Abstract:
A gas laser oscillator comprising:(a) at least three discharge tubes disposed in series along an optical axis of a laser beam, said discharge tubes defining an interior discharge space;(b) a fully reflective mirror disposed in the vicinity of a first opening of said discharge space for providing a terminal mirror;(c) a partially reflective mirror disposed in the vicinity of a second opening of said discharge space for providing an output mirror; and(d) a spacer disposed between said partially reflective mirror and a closest one of said discharge tubes, said spacer having an opening that is centered on the optical axis of the laser beam,wherein said discharge tubes satisfy the following three formulas simultaneously:r1/r2>1.0 Formula 1L2/(L1+L2)<0.85 Formula 2r3/r2<1.4 Formula 3where L1 represents the sum of the lengths of said discharge tubes disposed at both ends in the optical axis direction, r1 represents the inside diameter of these discharge tubes, L2 represents the sum of the lengths of the other discharge tubes in the optical axis direction, r2 represents the inside diameter of the other discharge tubes, and r3 represents the inside diameter of the opening of said spacer.