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, N2, KrF, and F2. The laser oscillation and the gain measurement are examined here in N2 and F2 lasers. The discharge tube consists of a ceramic pipe of 15 cm in length and 5 mm 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/cm3, the output energy of 140 (mu) J/pulse with 18 ns duration was obtained at a very low total gas pressure of 40 Torr (5.3 kPa) with a F2 concentration of 1.5%. On the other hand at the same charging voltage and an excitation density of 1.5 MW/cm3, the output energy was 100 (mu) J/pulse with 16 ns duration at a high total gas pressure of 1 atm (101 kPa) with a F2 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.