On the nonuniformity of the output beam power density of a nitrogen laser

The distribution of the UV power density in the 337.1-nm C 3Πu - B 3Πg band over the output beam cross section of a transverse-discharge-pumped nitrogen laser is studied experimentally. It is shown that for the nitrogen pressure up to tens of torr and large laser pulse durations, the radiation power density from the cathode discharge region is lower than that from the rest part of the discharge gap. The potential distribution in the cathode discharge region is analysed theoretically. It is shown that the length of the cathode region with a low radiation power density observed in the experiment corresponds approximately to the length of the dark Faraday space in an anomalous glow discharge. (lasers, active media)