Longitudinally excited F2 laser and gain measurement at a total gas pressure of 40 Torr

A new scheme of longitudinally excited gas lasers has been developed. This provides compact and stable gas lasers of CO2, N-2, KrF, and F-2. The laser oscillation and the gain measurement are examined here in N-2 and F-2 lasers. The discharge tube consists of a ceramic pipe of 15 cm in length and 5 nun in inner diameter, which is driven by a conventional capacitor transfer circuit, with the pre-ionization by a specially designed corona electrode. In the F2 lasers at a charging voltage of 20 kV and an excitation density of 2.3 MW/cm(3), the output energy of 140 muJ/pulse with 18 ns; duration was obtained at a very low total gas pressure of 40 Torr (5.3 kPa) with a F-2 concentration of 1.5%. On the other hand at the same charging voltage and an excitation density of 1.5 MW/cm(3), the output energy was 100 muJ/pulse with 16 ns duration at a high total gas pressure of 1 atm (101 kPa) with a F-2 concentration of 0.2%. The maximum gain coefficients was around 13.5%/cm, and 11%/cm by the time resolved gain measurement for the low and the high total pressure operations, respectively.