Nitrogen lasers: Optical devices of variable gain coefficient

A N2-laser system, consists of an oscillator and an amplifier of different electrode lengths, ranged from 5 to 31 cm, operating under the optimized gas pressures conditions and 14 kV input voltage, was used to measure small signal gain, g0, and saturation energy density, Es. It was found that g0-parameter follows a profile of the type m + n/lAMP, where lAMP is the effective electrode length of the laser amplifier, and (m, n) are some constants. So, by reducing the active length a gain value as high as ∼1.2 cm−1 for lAMP = 5 cm was obtained. The proposed function, with a rather good approximation, can be used to explain almost all the reported g0-values of laser systems with moderate current densities. For explaining more details of the reported gain coefficients, the g0lAMP-parameter was introduced, where it was realized that with a good approximation a Gaussian profile is a suitable function for explaining the reported g0lAMP-products. Furthermore, we found that at a constant input voltage the saturation energy density and output energy density, Eout, regardless of the type of N2-lasers and their operational conditions, are linearly correlated. Based on this observation, and by operating the system at different input voltages, the functional dependence of the measured Es/Eout-values with respect to the operational voltages is introduced. Details of our present observations, along with the previously reported g0, and Es-measurements are presented graphically, or tabulated. The results are giving some interesting features of TE/TEA N2-lasers for lasers g0, Es predictions which are valuable for laser designs and also for further theoretical investigations.