Patent ID: 7130324

Claim:
A gas laser oscillator comprising: a discharge tube for exciting laser gas; a laser gas passage connected to said discharge tube; a laser gas circulator for circulating the laser gas in said laser gas passage as well as in said discharge tube; and a permeable screen plate provided at a position of said laser gas passage; wherein said laser gas circulator is provided at a position of said laser gas passage; wherein said screen plate is provided between said laser gas circulator means and said discharge tube; wherein said screen plate is meshed; and wherein the following inequalities are satisfied: 6.0×10 4 Pa·m 3 /min< Q×P< 1.5×10 6 Pa·m 3 /min D/λ< 10 A/λ< 10 −2 0.2 <B/S< 0.7 where Q (m 3 /min) is a mass flow rate of the laser gas, P (Pa) is a pressure of the laser gas, λ(mm) is a wavelength of a compression wave in the laser gas that results from pressure fluctuation, D (mm) is an inside diameter of said laser gas passage in the vicinity of said screen plate, A (mm) is a mesh diameter of said screen plate, S (mm 2 ) is a total sectional area of said screen plate, and B (mm 2 ) is a total mesh area of said screen plate.