Stimulated emission and amplification characteristics of an excimer XeCl laser emitting pulses of 0.5 μs duration

An excimer laser emitting long pulses was developed. It was pumped by a double discharge with ultraviolet preionization based on a capacitor discharge across an insulator. The length of the active medium of the laser was 50 cm and the beam cross section was 2 X 2.5 cm. A transmission line with a wave impedance ρ ≈ 0.4 Ω was used as the source of the main discharge. Stimulated emission was in the form of ~ 500 ns pulses with an energy up to ~ 200 mJ when the overall laser efficiency was η_Σ = 1.2% and the efficiency calculated on the basis of the energy stored in the transmission line was up to η_tr = 1.7%. A study was made of the dynamics of changes in the small-signal gain g₀ when the specific pump power was P_V = 50–100 kW/cm³. It was established that in this range of P_V the gain was within the range g₀ = (2–3) X 10 ^{– 2} cm ^{– 1}.