Characteristics of a high-power NH$_3$–N$_2$ laser with passive longitudinal mode locking

The results are given of an investigation into the characteristics of an NH$_3$–N$_2$ laser operating in the passive mode locked regime. Pulses of $\sim7$ nsec duration were obtained in the range $745-928$ cm$^{-1}$ and the total laser output energy was up to 70% of that without mode locking. The optimal parameters of a gas absorption cell and of the NH$_3$–N$_2$ laser operating regime with a bleachable filter were found. It was found that adding a buffer gas to the cell made it possible to satisfy the condition $\Delta\nu_{\mathrm{abs}}\gtrsim\Delta\nu_g$ with the minimum possible losses in the absorber. A possible procedure was suggested for increasing the power of the NH$_3$–N$_2$ laser by an order of magnitude.