Influence of the lamp filling on the pumping conditions in a pulsed YAG:Nd3+ laser

The pumping conditions in pulsed YAG:Nd³⁺ lasers are determined, to a great extent, by the filling and the discharge conditions in the pump lamps. It is reported that the highest efficiency under free-oscillation conditions was obtained when krypton discharge lamps were used. These lamps had a discharge gap 60 mm long and 5 mm in diameter. They emitted flashes of about 200 μsec duration. The best results were obtained when the initial gas pressure was ~1000 torr and the discharge energy was W ~ 100–150 J. The efficiency was lower when the value of W was either larger or smaller. The nature of the filling had little effect on the laser efficiency when xenon and krypton lamps were used to provide energies W close to the nominal value of 250 J. The pumping conditions could not be improved significantly by the use of other fillings (inert gases or their mixtures were used). The principal results obtained were valid also when the lamps were operated at a repetition frequency of ν ≈ 10 Hz.