Parametric Studies of a 13.56-MHz RF-Discharge-Pumped CO₂ Laser with Wide-Area Cylindrical Slab Geometry

Abstract

This paper describes the fundamental laser characteristics of a cylindrical slab-type CO₂ gas laser using an RF discharge frequency of 13.56 MHz. Discharge uniformity was investigated with an optical fiber probe by regulating the mixing ratio and the gas pressure of a gaseous medium. Results indicated that the optimum input pumping density of the laser medium was -3 W/cm³ at a pressure of 5.3 kPa with a mixing ratio of CO₂: N₂: He =1: 4: 15. A peak small-signal gain coefficient of 0.5 %/cm was obtained at the 10.6μm P (20) line. Moreover, a detailed small-signal gain analysis on some other P-branches indicated that the rotational temperature was in between 520 K and 560 K.