Abstract

A fast-axial-flow (FAF) CO₂ laser is one of the promising systems for high-power sources for machinery, welding, and medicine. We have experimentally observed temporal decrease of the amplified power after discharging plasma tubes within a few minutes in the FAF CO₂ laser amplifier.¹ We first theoretically analyze the power decrease Δ\ transient time to have stable output t_st, and the small-signal gain γ by taking account of the gas flow velocity, discharge current, input intensity, and plasma length into the gain constant. Then the theoretical estimates of ΔP, t_st, and γ are compared with the experimentally obtained results in the FAF (500-W class) amplifier.

© 1988 Optical Society of America