Nitrogen lasers represent a class of gas discharge lasers producing a stimulated emission on electronic-vibrational transitions of a nitrogen molecule in the UV with the main bands I=337,1 nm. I=357,7 nm, I=315,9 nm.

Due to the unfavorable correlation between the probabilities of a radiative decay of operating levels of a nitrogen molecule the inversion (that is, laser action) on the indicated transitions can be obtained only in pulsed mode of operation on the rising edge of the excitation pulse. Thus, nitrogen laser operates on self-limited transitions.