Gain characteristics of CO2laser amplifiers at 10.6 microns

• Published in: 1966 International Electron Devices Meeting pp. 112 - 114
• Main Authors: Cheo, P.K., Cooper, H.G.
• Format: Conference Proceeding
• Language: English
• Published: IRE 1966
• Subjects: Boring; Current density; Gain; Gas lasers; Gases; Helium; Hydrogen; Pulse amplifiers; Pulse measurements; Temperature
• DOI: 10.1109/IEDM.1966.187736

Single-pass gain at 10.6 microns has been studied parametrically in nonflowing CO 2 or buffered CO 2 amplifying media. The gain profile across the amplifier diameter and integrated gain both were determined. Parameters varied included buffer gas type, mixture ratio, gas pressure, amplifier bore, discharge current, and wall temperature. Tube bores of 12, 22, and 34 mm and buffer gases of H 2 , He, Ne, A, O 2 , and N 2 were studied. For CW laser amplifiers, optimum gain is relatively independent of current density, but decreases with wall temperature. A pressure-diameter product of about 4 torr-cm was found to hold for CO 2 , CO 2 :He, and CO 2 :N 2 amplifying media at optimum gain. The gain depends strongly on the CO 2 partial pressure and is relatively insensitive to the buffer gas pressure. The highest gain, 1.7 db/meter, was achieved in helium buffered CO 2 amplifiers with a diameter, of 22 mm or less. Addition of N 2 to the optimum CO 2 :He mixture reduced the gain. The maximum gain decreased slowly with the amplifier diameter. Addition of hydrogen to CO 2 quenched the inversion of CO 2 01°0 - 00°1 levels. No gain saturation was detected for a 30 db range of input signal power, from a milliwatt to a few watts. Pulsed gain measurements are also presented.