The design and coherence properties of a simple N2laser

Abstract

A compact electrical pulse circuit suitable for exciting pulsed gas lasers has been developed. The advantages are the low input voltage (10-20 kV) and the possibility of an output voltage of more than 100 kV. The rise time was found to be less than 10 ns. The design is described and has been used to excite a nitrogen laser. A maximum output power of 500 kW (pulselength 5 ns) with a repetition rate of 1 Hz was achieved from a 36 cm long tube, 6 mm diameter. When the repetition rate was 100 Hz the output power was about 50 kW. The spatial and temporal coherence was also studied. It was found that the spatial coherence existed over the whole cross section of the beam. By operating the laser below the saturation level and introducing mirrors the pulse length could be changed in the range 4-10 ns. The time coherence was approximately equal to the halfwidth of pulse. The beam divergence was improved by a factor of 1o by using a complete cavity instead of a single rear mirror.